Heart: Cardiovascular pathology

B Hypertrophic cardiomyopathy is familial in >70% of cases and is usually transmitted as an autosomal dominant trait. The mutations affect genes that encode proteins of cardiac contractile elements. The most common mutation in the inherited forms affects the β-myosin heavy chain. Autoimmune conditions are unlikely to involve the myocardium. Amyloidosis causes restrictive cardiomyopathy. Hemochromatosis can give rise to cardiomyopathy, but it occurs much later in life. Viral infections produce generalized inflammation and cardiac dilation.

A 10-year-old girl who is normally developed has chronic progressive exercise intolerance. On physical examination, temperature is 37.1° C, pulse is 70/min, respirations are 14/min, and blood pressure is 100/60 mm Hg. A chest radiograph shows cardiomegaly and mild pulmonary edema. An echocardiogram shows severe left ventricular hypertrophy and a prominent interventricular septum. The right ventricle is slightly thickened. During systole, the anterior leaflet of the mitral valve moves into the outflow tract of the left ventricle. The ejection fraction is abnormally high, and the ventricular volume and cardiac output are both low. Which of the following is the most likely cause of the cardiac abnormalities in this patient? A Autoimmunity against myocardial fibers B β-Myosin heavy chain gene mutation C Deposition of amyloid fibrils D Excessive iron accumulation E Latent enterovirus infection

E The mitral valve in the figure shows shortening and thickening of the chordae tendineae typical of chronic rheumatic valvulitis, and the small verrucous vegetations (arrowheads) are characteristic of superimposed acute rheumatic fever. Valvular scarring can follow years after initial group A streptococcal infection. Rheumatic heart disease develops after the immune response directed against the bacterial antigens (similar to cardiac antigens, and thus a form of molecular mimicry) damages the heart because streptococcal antigens cross-react with the heart. The mitral and aortic valves are most commonly affected, so right ventricular dilation from tricuspid involvement is less likely. In almost all cases, the fibrinous pericarditis seen during the acute phase with friction rub resolves without significant scarring, and constrictive pericarditis does not typically develop. Although there is myocarditis with acute rheumatic fever, it does not lead to dilated cardiomyopathy. A left ventricular aneurysm is a complication of ischemic heart disease. Primary cardiac neoplasms, including myxoma, are rare and not related to infection.

A 14-year-old girl has fever and chest pain 2 weeks after having a mild upper respiratory tract infection. On physical examination, her temperature is 37° C, pulse is 90/min, respirations are 20/min, and blood pressure is 85/45 mm Hg. A friction rub is audible on auscultation of the chest. A chest radiograph shows pulmonary edema. An echocardiogram shows small vegetations at the closure line of the mitral and aortic valves. An endomyocardial biopsy shows focal interstitial aggregates of mononuclear cells enclosing areas of fibrinoid necrosis. Her condition improves over the next month. The representative gross appearance of the affected heart is shown in the figure. Which of the following cardiac abnormalities is most likely to occur in this patient? A Constrictive pericarditis B Dilated cardiomyopathy C Left ventricular aneurysm D Myxoma E Valvular stenosis

B In children and adults, the coarctation is typically postductal, and collateral branches from the proximal aorta supply the lower extremities, leading to the large pulse differential between upper and lower extremities. Collaterals often involve intercostal arteries whose enlargement produces 176"rib notching" on chest radiographs. Diminished renal blood flow below the coarctation increases renin production and promotes hypertension. Aortic valve stenosis causes left-sided heart failure and no pressure differential in the extremities. A patent ductus arteriosus produces a small left-to-right shunt. Transposition results in a right-to-left shunt with cyanosis. Tricuspid valve atresia affects the right side of the heart.

A 15-year-old boy complains of pain in his legs when he runs more than 300 m. Physical examination shows temperature, 36.8° C; pulse, 76/min; respirations, 22/min; and blood pressure, 165/90 mm Hg. The radial pulses are 4+, and the dorsalis pedis pulses are 1+. Arterial blood gas measurement shows a normal oxygen saturation level. Which of the following congenital cardiovascular anomalies is most likely to be present in this patient? A Aortic valve stenosis B Coarctation of the aorta C Patent ductus arteriosus D Transposition of the great arteries E Tricuspid valve atresia

C. A stab wound into heart can lead to hemopericardium with cardiac tamponade. The blood around the heart interferes with cardiac motion, reducing the ejection fraction, and diminishes the heart sounds.

A 16-year-old healthy adolescent is involved in a schoolyard gang fight and is stabbed in the chest with a knife in the left midclavicular line. He is taken to the emergency department and on arrival his blood pressure is barely obtainable. His lungs are clear to auscultation. His heart sounds are barely audible. Which of the following is the most useful therapeutic approach for this boy? A Coronary angioplasty B Aortic repair C Pericardiocentesis D Antibiotic therapy E Antiarrhythmic drugs

B. She has coarctation of the aorta, and the constriction is postductal, allowing prolonged survival. Blood pressure is elevated in the upper body but reduced in the lower body. Her physical characteristics also suggest Turner syndrome (monosomy X). (D) Incorrect. When the spiral septum does not develop properly, a truncus arteriosus can result, with mixing of right and left heart blood, leading to cyanosis. (A) Incorrect. Such mitral valve findings are found with chronic rheumatic valvulitis that is typically seen in adults years after episode(s) of rheumatic fever.

A 17-year-old girl is short in stature for her age. She has not yet shown any changes of puberty. On physical examination her vital signs include T 37°C, RR 18/minute, P 75/minute, and BP 165/85 mm Hg. She has a continuous murmur heard over both the front of the chest as well as her back. Her lower extremities are cool with diminished pulses and poor capillary filling. She has a webbed neck. A chest radiograph reveals a prominent left heart border, no edema or effusions, and rib notching. Which of the following cardiovascular abnormalities is she most likely to have? A Shortening and thickening of chordae tendineae of the mitral valve B Narrowing of the aorta past the ductus arteriosus C Supravalvular narrowing in the aortic root D Lack of development of the spiral septum and partial absence of conus musculature E Single large atrioventricular valve

B Hypertrophic cardiomyopathy is the most common cause of sudden unexplained death in young athletes. There is asymmetric septal hypertrophy that reduces the ejection fraction of the left ventricle, particularly during exercise. Histologically, haphazardly arranged hypertrophic myocardial fibers are seen. Arrhythmias can occur. If persons with this condition survive to adulthood, chronic heart failure may develop. Hemochromatosis gives rise to a cardiomyopathy in middle age. Valve destruction with vegetations is seen in infective endocarditis and would be accompanied by signs of sepsis. Rheumatic heart disease with chronic valvular changes would be unusual in a patient this age, and the course is most often slowly progressive. Tachyzoites of Toxoplasma gondii signify myocarditis, a process that may occur in immunocompromised individuals.

A 17-year-old girl jumps up for a block in the third match of a volleyball tournament and suddenly collapses. She requires cardiopulmonary resuscitation. A similar episode occurs a month later. She had been healthy all her life and complained only of limited episodes of chest pain in games during the current school year. Which of the following pathologic findings of the heart is most likely to be present in this girl? A Extensive myocardial hemosiderin deposition B Haphazardly arranged hypertrophied septal myocytes C Large, friable vegetations with destruction of aortic valve cusps D Mitral valvular stenosis with left atrial enlargement E Tachyzoites within foci of myocardial necrosis and inflammation

D Prolonged fever, heart murmur, mild splenomegaly, and splinter hemorrhages suggest a diagnosis of infective endocarditis. The valvular vegetations with infective endocarditis are friable and can break off and embolize. The time course of weeks suggests a subacute form of bacterial endocarditis resulting from infection with a less virulent organism, such as viridans streptococci. Group A streptococci are better known as a cause for rheumatic heart disease, with noninfectious vegetations. Pseudomonas aeruginosa is more likely to cause an acute form of bacterial endocarditis that worsens over days, not weeks; this organism is more common as a nosocomial infection or it may occur in injection drug users. Coxsackievirus B and Trypanosoma cruzi are causes of myocarditis. Tuberculosis involving the heart most often manifests as pericarditis.

A 19-year-old man has had a low-grade fever for 3 weeks. On physical examination, his temperature is 38.3° C, pulse is 104/min, respirations are 28/min, and blood pressure is 95/60 mm Hg. A tender spleen tip is palpable. There are splinter hemorrhages under the fingernails and tender hemorrhagic nodules on the palms and soles. A heart murmur is heard on auscultation. Which of the following infectious agents is most likely to be cultured from this patient's blood? A Coxsackievirus B B Mycobacterium tuberculosis C Pseudomonas aeruginosa D Viridans streptococci E Trypanosoma cruzi

D. The bioprosthesis has the advantage of not requiring anticoagulation, but it does not wear well with time, and typically must be replaced within 5 to 10 years when its leaflets undergo progressive calcification leading to stenosis. (E) Incorrect. Patients with mechanical prostheses are given anticoagulant therapy, but persons with bioprostheses do not need this medication.

A 24-year-old woman with rheumatic heart disease becomes febrile. On physical examination she has a systolic murmur. An echocardiogram shows vegetations of the aortic valve cusps. A blood culture is positive for Staphylococcus epidermidis. She receives a porcine bioprosthesis because of her desire to have children and not to take anticoagulant medication. After ten years, she must have this prosthetic valve replaced. Which of the following pathologic findings in the bioprosthesis has most likely led to the need for replacement? A Dehiscence B Endocarditis C Strut failure D Calcification E Thrombosis

D. Marfan syndrome is a connective tissue disorder that is associated with floppy mitral valve and also with cystic medial necrosis that predisposes to aortic dissection. The sudden cardiac death in this case is due to the valvular abnormality. (F) Incorrect. The dystrophin gene is mutated with Duchenne muscular dystrophy, affecting striated muscle, which can lead to cardiac failure as the disease progresses. However, the onset of muscular weakness occurs early in life. (A) Incorrect. Mutations of the beta-myosin gene may be associated with some cases of hypertrophic cardiomyopathy.

A 19-year-old woman has had increasing malaise for the past 5 months. On physical examination she has a cardiac murmur characterized by a mid systolic click. An echocardiogram demonstrates mitral insufficiency with upward displacement of one leaflet. There is aortic root dilation to 4 cm. She has a dislocated right ocular crystalline lens. A year later she dies suddenly and unexpectedly. The medical examiner finds a prolapsed mitral valve with elongation, thinning, and rupture of chordae tendineae. A mutation involving which of the following genes is most likely to be present in this patient? A Beta-myosin B CFTR C FGFR D Fibrillin E Spectrin F Dystrophin

D Although often not causing a large shunt defect, a patent ductus arteriosus can produce a significant murmur and predispose to infection. This left-to-right shunt may eventually result in pulmonary hypertension. An atretic valve has no flow across it and does not produce a murmur, but there would be a murmur across a shunt around the atretic valve. Aortic atresia is not compatible with continued survival, as seen in hypoplastic left heart syndrome. Aortic coarctations by themselves produce no shunting and no pulmonary hypertension. An atrial septal defect is unlikely to produce a loud murmur because of the minimal pressure differential between the atria. Because pulmonic stenosis is a component of tetralogy of Fallot, no pulmonary hypertension results, and the right-to-left shunting can lead to cyanosis with decreased arterial oxygen saturation. Total anomalous pulmonary venous return is not accompanied by a murmur because of the low venous pressure

A 2-year-old child had an illness 1 year ago characterized by a high fever. Staphylococcus epidermidis was cultured from the blood. The child was given antibiotic therapy and recovered. Now on physical examination, a harsh, waxing and waning, machinery-like murmur is heard on auscultation of the upper chest. A chest radiograph shows prominence of the pulmonary arteries. Echocardiography shows all cardiac valves to be normal in configuration. Laboratory studies show normal arterial oxygen saturation level. Which of the following congenital heart diseases is most likely to explain these findings? A Aortic atresia B Aortic coarctation C Atrial septal defect D Patent ductus arteriosus E Tetralogy of Fallot F Total anomalous pulmonary venous return

C These findings are compatible with hypoplastic left heart syndrome, which may have varying degrees of severity, ranging from severe (as in this case, with virtually no function on the left side of the heart) to milder degrees of hypoplasia. Most of the oxygenated blood returning to the left atrium is shunted across the foramen ovale back to the lungs, increasing pulmonary flow and decreasing oxygenation. Less oxygenated blood exiting the right ventricle into the pulmonic trunk can shunt through a patent ductus arteriosus to the aorta to supply the systemic circulation. Anomalous venous return does not generally connect to the aorta, and there still must be a connection from the lungs to the aorta. The right fourth aortic arch rarely persists. Truncus arteriosus is an anomalous, incomplete separation of the pulmonic and aortic trunks. If there is virtually no left ventricular chamber, a ventricular septal defect would not provide any significant flow.

A 21-year-old primigravida gives birth at term to a 2800-g infant with no apparent external anomalies. The next day, the infant develops increasing respiratory distress and cyanosis. Echocardiography reveals a slitlike left ventricular chamber, small left atrium, and atretic aortic and mitral valves. Through which of the following structures could blood from the lungs most likely have reached the infant's systemic circulation? A Anomalous venous return B Foramen ovale C Patent ductus arteriosus D Right fourth aortic arch E Truncus arteriosus F Ventricular septal defect

B. The history points to infectious endocarditis and acute congestive heart failure. Staphylococcus aureus and Pseudomonas aeruginosa are the most likely organisms to be found with a history of injection drug use. (D) Incorrect. His heart failure, if severe, could reduce cardiac output and lead to pre-renal azotemia if he survives. (A) Incorrect. The CK-MB is typically elevated with ischemic heart disease, which would be unusual at his age.

A 22-year-old man has had increasing malaise over the past 3 weeks. On physical examination his vital signs show T 39.2°C, P 105/minute, RR 30/minute, and BP 80/40 mm Hg. On auscultation of his chest a loud systolic cardiac murmur is heard, and his lungs have bibasilar crackles. Needle tracks are seen in his left antecubital fossa. He has splinter hemorrhages noted on fingernails, as well as painful erythematous nodules on palmar surfaces. A tender spleen tip is palpable. A chest radiograph shows pronounced pulmonary edema. Which of the following laboratory test findings is most likely to be present in this patient's peripheral blood? A Creatine kinase-MB of 8% with a total CK 389 U/L B Positive blood culture for Pseudomonas aeruginosa C Total serum cholesterol of 374 mg/dL D Blood urea nitrogen of 118 mg/dL E Antinuclear antibody titer of 1:512

B. The poor outcome so soon after birth suggests a severe defect, and lack of sufficient left heart to provide appropriate cardiac output can explain these findings. There can be varying degrees of hypoplasia which determine how long the child survives.

A 23-year-old primigravida gives birth following an uncomplicated pregnancy to a 2870 gm girl infant. The baby initially does well, but 12 hours following delivery she develops respiratory difficulty. On examination the infant has a poor color, weak pulses, and oxygen saturation of only 90%. Which of the following cardiac findings is this infant most likely to have? A Muscular ventricular septal defect B Hypoplastic left heart C Complete transposition with no shunt D Secundum type atrial septal defect E congenital Group B Streptococcus infection

C. Patients with systemic lupus erythematosus can develop Libman-Sacks endocarditis, but the sterile, non-infectious vegetations are never large and they rarely embolize, so the endocarditis is not clinically significant in most cases. She probably has a friction rub from fibrinous pericarditis as a result of uremia from renal failure.

A 23-year-old woman has had worsening malaise along with a malar skin rash persisting for 3 weeks. On physical examination, she has an audible friction rub on auscultation of the chest, along with a faint systolic murmur. An echocardiogram reveals small vegetations on the mitral valve and adjacent ventricular endocardium. Laboratory studies show a positive serologic test for anti-Smith antibody, with a titer of 1:2048. Which of the following is the most likely diagnosis? A Polyarteritis nodosa B Scleroderma, diffuse C Systemic lupus erythematosus D ANCA-associated granulomatous vasculitis E Adenocarcinoma of the pancreas

A. This finding has been associated with sudden death and cocaine use. It is thought that it may be mediated by high norepinephrine levels through blockage of catecholamine reuptake. Continued use may promote arteriopathy in small peripheral coronary branches.

A 25-year-old man dies suddenly and unexpectedly while at a nightclub late one evening. The medical examiner performs an autopsy. There is no evidence for trauma on external examination of the body. There are no gross pathologic findings of internal organs. Postmortem toxicologic findings are significant for high blood levels of cocaine and its metabolite benzoylecgonine. Which of the following is the most likely histopathologic finding involving his heart? A Contraction band necrosis B Lymphocytic myocarditis C Myofiber disarray D Coronary thrombosis E Pericardial tamponade

A. Arrhythmogenic right ventricular cardiomyopathy (arrhythmogenic right ventricular dysplasia) is most likely an autosomal dominant inherited condition with abnormal desmosomal adhesion proteins in myocytes. Infections of the heart are accompanied by inflammation, though a late finding in Chagas disease is ventricular fibrosis with ventricular wall thinning. Hypertension leads to ventricular hypertrophy. There is no characteristic gross or microscopic finding with long QT syndrome caused by myocyte channelopathies. Prior radiation therapy results in fibrosis, but it is not likely to be localized to the right ventricle; improving techniques that focus the beam and synchronize it with breathing motion reduce cardiac damage when treating chest cancers.

A 25-year-old man suffers a sudden cardiac arrest. He is resuscitated. On examination his vital signs are normal. Echocardiography shows that the left ventricle is normal but there is marked thinning with dilation of the right ventricle. MR imaging of his chest shows extensive fibrofatty replacement of the myocardium, but no inflammation. Which of the following is the most likely cause for his findings? A Cardiomyopathy B Chagas disease C Hypertension D Long QT syndrome E Radiation therapy

E The aortic valve shown has large, destructive vegetations. The probe passes through a perforated leaflet, typical of infective endocarditis caused by highly virulent organisms such as Staphylococcus aureus. The verrucous vegetations of acute rheumatic fever are small and nondestructive, and the diagnosis is suggested by an elevated anti-streptolysin O titer. A positive ANCA determination suggests a vasculitis, which is unlikely to involve cardiac valves. An elevated creatine kinase-MB level suggests myocardial, not endocardial, injury. A positive double-stranded DNA finding suggests systemic lupus erythematosus, which can produce nondestructive Libman-Sacks endocarditis.

A 25-year-old man was found dead at home by the apartment manager, who had been called by the decedent's employer because of failure to report to work for the past 3 days. An external examination by the medical examiner showed splinter hemorrhages under the fingernails and no signs of trauma. The gross appearance of the heart at autopsy is shown in the figure. Which of the following laboratory findings is most likely to provide evidence for the cause of his disease? A Elevated anti-streptolysin O titer B Positive ANCA serology C Increased creatine kinase-MB (CK-MB) fraction D High double-stranded DNA autoantibody titer E Positive blood culture for Staphylococcus aureus

A. The most common cause for a primary myocarditis is a virus (such as Coxsackie virus). The myocardial fiber necrosis with lymphocytic infiltrates are consistent with viral infection. Viral myocarditis can be a cause for sudden death in a young person. (D) Incorrect. Streptococcus viridans group is a cause for bacterial endocarditis. A myocarditis could be produced from septic emboli from vegetations, but this is not common. (G) Incorrect. Group A streptococcal infections are a cause for rheumatic fever, which may produce a myocarditis with granulomatous inflammation characterized by Aschoff nodules.

A 25-year-old previously healthy woman collapses suddenly and unexpectedly. Echocardiography shows global hypokinesis with increased left ventricular end diastolic and systolic size, along with systolic left ventricular dysfunction with decreased ejection fraction. An endomyocardial biopsy is obtained and microscopically, the myocardium shows infiltration by small lymphocytes, with focal myocyte necrosis. Which of the following infectious agents is most likely to have caused these findings? A Coxsackie B virus B Candida albicans C Aspergillus fumigatus D Streptococcus, viridans group E Staphylococcus aureus F Cytomegalovirus G Streptococcus, group A

C. She has a febrile illness with findings that suggest myocarditis, which can have features of cardiomyopathy because of the diffuse myocardial involvement. The most likely organisms are enteroviruses (coxsackie B virus, echovirus) as well as adenoviruses. (A) Incorrect. An elevation of the ASO titer suggests a recent streptococcal infection that might be associated with rheumatic fever. The infection, typically a pharyngitis, is gone by the time the ASO titer is elevated and the cardiac lesions, including myocarditis, are present.

A 26-year-old previously healthy woman has had worsening fatigue with dyspnea, palpitations, and fever over the past week. On physical examination her vital signs show T 38.9°C, P 104/minute, RR 30/minute, and BP 95/65 mm Hg. Her heart rate is slightly irregular. An ECG shows diffuse ST-T segment changes. A chest x-ray shows mild cardiomegaly. An echocardiogram shows slight mitral and tricuspid regurgitation but no valvular vegetations. Laboratory studies show a troponin I of 12 ng/mL. She recovers over the next two weeks with no apparent sequelae. Which of the following laboratory test findings best explains the underlying etiology for these events? A Anti-streptolysin O titer of 1:512 B Total serum cholesterol of 537 mg/dL C Echovirus serologic titer of 1:160 D Blood culture positive for Streptococcus, viridans group E ANCA titer of 1:80

A. This history points to an infective endocarditis. A common risk factor for infective endocarditis, particularly with more severe and acute disease, is intravenous drug use.

A 35-year-old man was found down, was delirious, and talking incoherently. On examination in the emergency department his temperature is 39.3°C, pulse 110/minute, and blood pressure 70/palpable. He has a heart murmur, palpable spleen tip, and splinter hemorrhages of fingernails. Which of the following laboratory findings is most likely to be present in this man? A Positive urine screen for opiates B Elevated anti-streptolysin O (ASO) C Increased urinary free catecholamines D Elevated Coxsackie B viral titer E Rising creatine kinase (CK) in serum

E Reperfusion of an ischemic myocardium by spontaneous or therapeutic thrombolysis changes the morphologic features of the affected area. Reflow of blood into vasculature injured during the period of ischemia leads to mitochondrial dysfunction, followed by leakage of blood into the tissues (hemorrhage). Contraction bands are composed of closely packed hypercontracted sarcomeres. They are most likely produced by exaggerated contraction of previously injured myofibrils that are exposed to a high concentration of calcium ions from the plasma. The damaged cell membrane of the injured myocardial fibers allows calcium to penetrate the cells rapidly. Free radical formation and release of leukocyte enzymes further potentiate myocardial cell death. Hemorrhage would not be a prominent feature in the other listed options. Vasculitides involving the heart are uncommon; Takayasu arteritis can involve coronary arteries, but is most often a rare pediatric condition. Drugs used to control arrhythmias during acute coronary syndromes are unlikely to have hemorrhage as an adverse event. Angioplasty per se does not increase the risk for hemorrhage, and stents help to keep the artery open longer. Septic embolization from infected valvular vegetations to a coronary artery is uncommon, although such emboli may produce focal necrosis and hemorrhage.

A study of ischemic heart disease analyzes cases of individuals hospitalized with acute chest pain in which myocardial infarction was documented at autopsy. The gross and microscopic appearances of the hearts are correlated with the degree of coronary atherosclerosis and its complications, clinical symptoms, and therapies given before death. Hemorrhage and contraction bands in necrotic myocardial fibers are most likely to be seen with infarction in which of the following settings? A Acute coronary vasculitis B Anti-arrhythmic drug usage C Angioplasty with stent placement D Septic embolization E Thrombolytic therapy

A She developed bacterial septicemia followed by infective endocarditis of the mitral valve. Thus she has a high risk for developing complications of infective endocarditis. Such valvular vegetations are destructive of the valve. The impaired functioning of the mitral valve (most likely regurgitation) would give rise to left atrial dilation and left ventricular failure with pulmonary edema. Septic emboli from the mitral valve vegetation could reach the systemic circulation and give rise to abscesses. Infection of an arterial wall can weaken the wall, resulting in aneurysm formation and the potential for rupture. Dilated cardiomyopathy may be due to chronic alcoholism, or it may be idiopathic. It may be familial, or it may follow myocarditis, but it is not a direct complication of infective endocarditis. Myxomatous degeneration of the mitral valve results from a defect in connective tissue, whether well defined or unknown; the mitral valve leaflets are enlarged, hooded, and redundant. Lesions on the right side of the valve can produce septic emboli that involve the lungs, but vegetations on the left side embolize to the systemic circulation, producing lesions in the spleen, kidneys, or brain. Pulmonary abscesses can occur from right-sided infective endocarditis, because septic emboli pour into the pulmonary arterial circulation.

A 26-year-old woman has had a fever for 5 days. On physical examination, her temperature is 38.2° C, pulse is 100/min, respirations are 19/min, and blood pressure is 90/60 mm Hg. A cardiac murmur is heard on auscultation. Her sensorium is clouded, but there are no focal neurologic deficits. Laboratory findings include hemoglobin, 13.1 g/dL; platelet count, 233,300/mm3; and WBC count, 19,200/mm3. Blood cultures are positive for gram-positive bacteria. Urinalysis shows hematuria. An echocardiogram shows a 1.5-cm vegetation on the mitral valve. Which of the following conditions is this patient most likely to develop? A Cerebral arterial mycotic aneurysm B Dilated cardiomyopathy C Myxomatous mitral valve degeneration D Pericardial effusion with tamponade E Pulmonary abscess

B. This congenital condition can predispose to infective endocarditis. If such conditions are known, then antibiotic prophylaxis can be given prior to invasive or dental procedures that increase the risk for bacteremia. (C) Incorrect. Chagas disease results from Trypanosoma cruzi infection and produces a myocarditits that may cause heart failure and arrhythmias acutely or chronically.

A 27-year-old man has become severely ill with fever and malaise over the past 3 days following tooth extraction. On examination he has a temperature of 38.8°C, heart rate of 105/minute, respiratory rate of 24/min, and blood pressure of 80/40 mm Hg. He has a widely split S2 heart sound and a rumbling mid-diastolic murmur. He has small hemorrhages visible on nail beds. His spleen tip is palpable. Which of the following cardiac conditions is most likely to predispose him to this acute illness? A Hypoplastic left heart syndrome B Atrial septal defect C Chagas disease D Coronary atherosclerosis E Hypertrophic cardiomyopathy

D The figure shows that the aorta emerges from the right ventricle, and the pulmonic trunk exits the left ventricle, consistent with complete transposition of the great vessels. Unless there is another anomalous connection between the pulmonary and systemic circulations, this condition is incompatible with extrauterine life. The most common additional anomalous connections would be ventricular septal defect, patent ductus arteriosus, and patent foramen ovale (or atrial septal defect). In pulmonic and aortic stenosis, the great arteries are normally positioned, but small. In tetralogy of Fallot, the aorta overrides a ventricular septal defect, but is not transposed. In truncus arteriosus, the spiral septum that embryologically separates the great arteries does not develop properly.

A 27-year-old woman gives birth to a term infant after an uncomplicated pregnancy and delivery. The infant is cyanotic at birth. Two months later, physical examination shows the infant to be at the 37th percentile for height and weight. The representative gross appearance of the infant's heart is shown in the figure. What is the most likely diagnosis? A Aortic stenosis B Pulmonic stenosis C Tetralogy of Fallot D Transposition of the great vessels E Truncus arteriosus

A The figure shows dark red blood filling the opened pericardial cavity, a massive hemopericardium with pericardial tamponade. After excluding trauma, a complication of ischemic heart disease should be suspected. Rupture of a transmural myocardial infarction typically occurs 3 to 7 days after onset, when there is maximal necrosis before significant healing of the infarct. Ischemic heart disease occurs in patients of his age, and risk factors such as obesity, smoking, diabetes mellitus, and hyperlipidemia can play a role in its development. Cardiomyopathies lead to ventricular hypertrophy or dilation, or both, but do not cause rupture. Tuberculosis can cause hemorrhagic pericarditis, typically without tamponade. Scleroderma is most likely to produce serous effusion. Metastases from melanoma and other carcinomas can produce hemorrhagic pericarditis without tamponade. This patient does not have a marfanoid habitus, although Marfan syndrome can cause cystic medial necrosis involving the aorta, leading to aortic dissection that can cause an acute hemopericardium. Takayasu arteritis can involve coronary arteries with aneurysms and rupture, but is most often a rare pediatric condition.

A 31-year-old man experienced chest pain, became increasingly dyspneic and nauseated, and lost consciousness multiple times. Seven days after the appearance of these symptoms, he was found dead in his sleep. External examination of the body by the medical examiner shows no evidence of trauma. The body is 166 cm (5 ft 5 in) in height and weighs 75 kg (BMI 27). The gross appearance of the chest cavity at autopsy with the pericardial sac opened is shown in the figure. What is the most likely underlying cause of his death? A Coronary atherosclerosis B Dilated cardiomyopathy C Disseminated tuberculosis D Systemic sclerosis E Malignant melanoma F Marfan syndrome G Takayasu arteritis

A Focal myocardial necrosis with a lymphocytic infiltrate is consistent with viral myocarditis. This is uncommon, and many cases may be asymptomatic. In North America, most cases are caused by coxsackieviruses A and B. This illness may often be self-limited. Less often, it ends in sudden death or progresses to chronic heart failure. Mycobacterial infections of the heart are uncommon, but pericardial involvement is the most likely pattern. Septicemia with bacterial infections may involve the heart, but the patient probably would be very ill with multiple organ failure. Viridans streptococci and Staphylococcus aureus are better known as causes of endocarditis with neutrophilic inflammatory infiltrates. Toxoplasma gondii may cause myocarditis with mixed inflammatory cell infiltrates in immunocompromised patients. Trypanosoma cruzi is the causative agent of Chagas disease, seen most often in children. This is probably the most common infectious cause of myocarditis worldwide.

A 33-year-old woman from Victoria, British Columbia, goes to the physician because of increasingly severe dyspnea, orthopnea, and swelling of the legs for the past 2 weeks. She has no previous history of serious illness or surgery. On physical examination, her temperature is 37.8° C, pulse is 83/min, respirations are 20/min, and blood pressure is 100/60 mm Hg. An ECG shows episodes of ventricular tachycardia. An echocardiogram shows right and left ventricular dilation, but no valvular deformities. An endomyocardial biopsy shows focal myocyte necrosis and lymphocytic infiltrate. Which of the following organisms most likely caused the infection? A Coxsackievirus A B Mycobacterium kansasii C Viridans streptococci D Staphylococcus aureus E Toxoplasma gondii F Trypanosoma cruzi

B A floppy (prolapsed) mitral valve is usually asymptomatic. When symptomatic, it can cause fatigue, chest pain, and arrhythmias. Some cases are linked to clinical depression and anxiety, and others are associated with Marfan syndrome. Valvular vegetations suggest endocarditis, and a murmur is likely to be heard with infective endocarditis causing valvular insufficiency. A patent ductus arteriosus causes a shrill systolic murmur. Pulmonic stenosis is most often a congenital heart disease. Tricuspid regurgitation is accompanied by a rumbling systolic murmur.

A 35-year-old woman has had palpitations, fatigue, and worsening chest pain during the past year. On physical examination, she is afebrile. Her pulse is 75/min, respirations are 15/min, and blood pressure is 110/70 mm Hg. Auscultation of the chest indicates a midsystolic click with late systolic murmur. A review of systems indicates that the patient has one or two anxiety attacks per month. An echocardiogram is most likely to show which of the following? A Aortic valvular vegetations B Mitral valve prolapse C Patent ductus arteriosus D Pulmonic stenosis E Tricuspid valve regurgitation

D. Angiosarcoma is a rare cardiac neoplasm (all primary cardiac neoplasms are rare) but the size alone suggests a malignancy.

A 37-year-old previously healthy man has had worsening dyspnea along with peripheral edema for the past two years. On physical examination he has diffuse crackles auscultated over both lungs. A chest radiograph shows that the heart nearly fills the chest. A chest CT scan demonstrates a 10 cm mass involving the right ventricle that appears to have areas of hemorrhage and necrosis within it. Which of the following neoplasms is this man most likely to have? A Rhabdomyosarcoma B Mesothelioma C Myxoma D Angiosarcoma E Papillary fibroelastoma F Kaposi sarcoma G Rhabdomyoma

C The figure shows a coronary artery with marked luminal narrowing caused by atheromatous plaque, complicated by a recent thrombus filling the narrowed lumen. Atherosclerosis is accelerated with diabetes mellitus. When a premenopausal woman develops severe atherosclerosis, as in this case, underlying diabetes mellitus or a lipid disorder must be strongly suspected. Patients with leukemias may have reversal of any atheromas, but can develop hypercoagulable states. When this occurs, there is widespread thrombosis in normal blood vessels. Individuals with chronic alcoholism often have less atherosclerosis than individuals of the same age who do not consume large amounts of alcohol. The cystic medial necrosis that occurs in Marfan syndrome most often involves the ascending aorta and predisposes to dissection that could involve coronary arteries, although with external compression. Polyarteritis nodosa can involve coronary arteries and give rise to coronary thrombosis when the arterial wall is necrotic and inflamed.

A 37-year-old woman has the sudden onset of chest pain. On examination she is afebrile but tachycardic and hypotensive. An ECG shows ST segment elevation and pathologic Q waves. The representative microscopic appearance of her left circumflex artery is shown in the figure. Which of the following underlying conditions is she most likely to have? A Acute myelogenous leukemia B Chronic alcoholism C Diabetes mellitus D Marfan syndrome E Polyarteritis nodosa

E Paroxysmal nocturnal dyspnea is a feature of left-sided congestive heart failure, and rheumatic heart disease most often involves the mitral, aortic, or both valves, and left-sided valvular disease leads to pulmonary edema. While upright, pulmonary edema fluid is more concentrated at lung bases, which helps improve breathing. Rheumatic heart disease was more common before antibiotic therapy for group A β-hemolytic streptococcal infections was available, and multiple bouts beginning in childhood led to valvular damage over decades. An atrial myxoma usually occurs on the left side of the heart, but the obstruction is often intermittent. Fibrinous pericarditis can produce chest pain, but the amount of accompanying fluid is often small so that cardiac function is not impaired. Giant cell myocarditis is a rare cause of cardiac failure. Libman-Sacks endocarditis, seen in systemic lupus erythematosus, typically does not impair valvular or ventricular function.

A 41-year-old woman has been awakened at night with "air hunger" for the past year. She notes sleeping better while sitting up in bed. Her serum B-type natriuretic peptide is >400 pg/mL (very high). What cardiac disease best explains her condition? A Atrial myxoma B Fibrinous pericarditis C Giant cell myocarditis D Libman-Sacks endocarditis E Rheumatic valvulitis

D Libman-Sacks endocarditis is an uncommon complication of systemic lupus erythematosus (SLE) that has minimal clinical significance because the small vegetations, although they spread over valves and endocardium, are unlikely to embolize or cause functional flow problems. Calcific aortic stenosis may be seen in older individuals with tricuspid valves, or it may be a complication of bicuspid valves. Although pericardial effusions are common in active SLE, along with pleural effusions and ascites from serositis, they are usually serous effusions, and no significant hemorrhage or scarring occurs. The vegetations of nonbacterial thrombotic endocarditis are prone to embolize. Mural thrombi are most likely to form when cardiac chambers are dilated, or there is marked endocardial damage. Rheumatic heart disease is an immunologic disease based on molecular mimicry; serologic tests would be positive for anti-streptolysin O (ASO), not ANA.

A 41-year-old woman has had increasing dyspnea for the past week. On physical examination, temperature is 37.3° C, pulse is 85/min, respirations are 20/min, and blood pressure is 150/95 mm Hg. There is dullness to percussion over the lung bases. A chest radiograph shows large bilateral pleural effusions and a normal heart size. Laboratory findings include serum creatinine, 3.1 mg/dL; urea nitrogen, 29 mg/dL; troponin I, 0.1 ng/mL; WBC count, 3760/mm3; hemoglobin, 11.7 g/dL; and positive ANA and anti-double-stranded DNA antibody test results. Which of the following cardiac lesions is most likely to be present in this patient? A Calcific aortic stenosis B Hemorrhagic pericarditis C Nonbacterial thrombotic endocarditis D Libman-Sacks endocarditis E Mural thrombosis F Rheumatic verrucous endocarditis

A The most common cause for sudden cardiac arrest is ischemic heart disease. The risk for sudden death is increased with worsening atherosclerotic coronary arterial narrowing. However, the first event with an acute coronary syndrome is typically an arrhythmia, and this is why resuscitation, including defibrillation, can be successful, and survivors may have no ECG or enzyme changes to suggest myocardial infarction has occurred. Inflammation with infarction or infection takes days to develop. A sudden valvular incompetence from papillary muscle rupture, or wall rupture, may complicate an infarction 3 to 7 days following the initial event.

A study of persons receiving emergent medical services is conducted. It is observed that 5% of persons with sudden cardiac arrest who receive cardiopulmonary resuscitation survive. Which of the following is the most likely mechanism for cardiac arrest in these survivors? A Arrhythmia B Infarction C Inflammation D Valve failure E Ventricular rupture

E. He has findings of a cardiomyopathy with right and left heart failure. Hereditary hemochromatosis can produce iron deposition in visceral organs, including the heart. The serum ferritin is a good indicator of body iron stores. Hemochromatosis affects the pancreas as well, leading to diabetes mellitus. Deposition of iron in joints leads to arthritis. There is a gradual increase in body iron stores, so that the onset of disease is typically in the 40's in males and 60's in females.

A 45-year-old man has had no major medical problems throughout his life, except for arthritis pain involving all extremities for the past 5 years. He has had worsening orthopnea and pedal edema in the past 6 months. There is no chest pain. On examination he is afebrile. A chest radiograph shows cardiomegaly with prominent left and right heart borders, along with pulmonary edema. Laboratory studies show serum sodium 139 mmol/L, potassium 4.3 mmol/L, chloride 99 mmol/L, CO2 25 mmol/L, urea nitrogen 18 mg/dL, creatinine 1.3 mg/dL, and glucose 167 mg/dL. Which of the following additional laboratory test findings is he most likely to have? A Spherocytes on his peripheral blood smear B Hemoglobin of 10.7 g/dL with MCV of 72 fL C Erythrocyte sedimentation rate of 79 mm/Hr D Anti-centromere antibody titer of 1:320 E Serum ferritin of 800 ng/mL

C. After 3 to 4 days following infarction, the muscle will still be necrotic and many neutrophils will persist, while macrophage infiltration will be beginning. (B) Incorrect. Granulation tissue with ingrowth of capillaries is most prominent after about a week after infarction and then collagenization becomes more prominent. (A) Incorrect. Collagenization becomes more prominent following the first week after a myocardial infarction as healing continues. After a couple of weeks, the infarct consists mainly of collagen.

A 45-year-old man was rushed to the hospital following the sudden onset of an episode of crushing substernal chest pain. He receives advanced life support measures. An EKG shows changes consistent with a large transmural anterolateral area of infarction involving wall of the left ventricle. He develops cardiogenic shock. Which of the following microscopic findings is most likely to be present in this area 4 days following the onset of his chest pain? A Fibroblasts and collagen deposition B Capillary proliferation and macrophages C Myofiber necrosis with neutrophils D Granulomatous inflammation E Perivascular lymphocytic infiltrates

C. Mitral valve stenosis leads to left atrial enlargement, but the left ventricle is usually small. There is typically a 'fishmouth' shaped mitral valve that has stenosis as well as insufficiency, since it does not close completely. Most mitral valvular disease in adults results from rheumatic valvulitis. The episode(s) of rheumatic fever occurred years before and the scarring of the valve developed slowly. (B) Incorrect. Cardiomyopathies often involve all heart chambers, including left ventricular hypertrophy with dilation, as well as right ventricular hypertrophy and dilation. (A) Incorrect. This is the most common cause for left ventricular hypertrophy, due to the pressure load from the hypertension. The left atrium is not typically enlarged with systemic hypertension.

A 45-year-old woman has had worsening shortness of breath for 3 years. She now has to sleep sitting up on two pillows. She has had difficulty swallowing for the past year. She has no history of chest pain. A month ago, she had a 'stroke' with resultant inability to move her left arm. She is afebrile. A chest radiograph reveals a near-normal left ventricular size with a prominent left atrial border. Which of the following conditions is most likely to account for her findings? A Essential hypertension B Cardiomyopathy C Mitral valve stenosis D Aortic coarctation E Patent foramen ovale

E. A He has both venous and arterial thromboembolic disease that suggests Trousseau syndrome. Non-bacterial thrombotic endocarditis (NBTE) is seen with this paraneoplastic condition. Though the small vegetations are bland, they often embolize, in this case in the systemic circulation to spleen and kidney. The highest rate of Trousseau syndrome occurs with high grade gliomas--about 25% of patients.

A 48-year-old man has had worsening severe headaches over the past 3 months. There are no abnormal findings on physical examination. Brain MR imaging shows a large 8 cm mass in the right posterior parietal region that extends across the splenium of the corpus callosum. A stereotaxic biopsy reveals an anaplastic astrocytoma. He is treated with radiation and chemotherapy. Two months later he experiences left upper quadrant abdominal pain, accompanied by hematuria. He then has an episode of sudden dyspnea and a chest CT scan shows large thromboemboli filling both main pulmonary arterial branches. Which of the following cardiovascular lesions is most likely to be found in this man? A Tear in the ascending aortic intima B Occlusive coronary atheromatous plaques C Hypertrophic cardiomyopathy D Epicardial metastases E Mitral marantic vegetations

C The figure shows intensely eosinophilic myocardial fibers with loss of nuclei, all are indicative of coagulative necrosis. The deeply red-stained transverse bands are called contraction bands. Neutrophils infiltrate between myocardial fibers. This pattern is most likely caused by a myocardial infarction (MI) that is approximately 24 to 48 hours old. Chest pain is present in most but not all cases of MI. Rheumatic myocarditis is characterized by minimal myocardial necrosis with foci of granulomatous inflammation (Aschoff bodies). There is no significant inflammation with restrictive cardiomyopathies such as amyloidosis or hemochromatosis. Septic emboli result in focal abscess formation. In viral myocarditis, there is minimal focal myocardial necrosis with round cell infiltrates.

A 48-year-old woman has had increasing dyspnea for the past 2 days. She experiences sudden cardiac arrest. The representative light microscopic appearance of her left ventricular free wall is shown in the figure. Which of the following is the most likely diagnosis? A Acute rheumatic myocarditis B Cardiomyopathy C Myocardial infarction D Septic embolization E Viral myocarditis

E. The findings suggest a predominantly right-sided congestive heart failure, which would be characteristic for cor pulmonale. Pulmonary hypertension most often results from obstructive or restrictive lung diseases. The second heart sound (S2) is comprised of aortic valve closure (A2) happening first and pulmonic valve closure (P2) occurring second. Normally, these are nearly superimposed. Normally, P2 is soft and heard only in the 2nd intercostal space at the left parasternal border. Increased pulmonary arterial pressure will increase the split and the loudness of P2.

A 50-year-old man has noted increasing swelling of his lower legs along with shortness of breath for 5 months. On physical examination he is afebrile, but diffuse crackles are heard over the lung bases. His heart rate is 80/minute and regular, with no murmurs, rubs, or gallops, but there is a prominent widened split S2. A chest radiograph reveals an increased size to the right heart border, along with bilateral pleural effusions. Laboratory studies show a serum troponin I of <0.4 ng/mL. Which of the following conditions is he most likely to have? A Alcoholic cardiomyopathy B Viral myocarditis C Bicuspid aortic valve D Constrictive pericarditis E Pulmonary interstitial fibrosis

C Atrial myxoma is the most common primary cardiac neoplasm. On the left side of the heart, it can produce a ball-valve effect that intermittently occludes the mitral valve, leading to syncopal episodes and possible strokes from embolization to cerebral arteries. Calcification of a bicuspid valve can lead to stenosis and heart failure, but this condition is progressive. Coronary artery thrombosis results in an acute ischemic event, typically with chest pain. By the time left atrial enlargement with mural thrombosis and risk of embolization occurs from mitral stenosis, this patient would have been symptomatic for years. Most pericardial effusions are not large and do not cause major problems. Large effusions could lead to tamponade, but this is not an intermittent problem.

A 48-year-old, previously healthy woman reports having suddenly lost consciousness four times in the past 6 months. In three instances, she was unconsciousness for only a few minutes. After the fourth episode 1 month ago, she was unconscious for 6 hours and had weakness in her right arm and difficulty speaking. On physical examination, she is afebrile, and her blood pressure is normal. No murmurs are auscultated. She has good carotid pulses with no bruits. Which of the following cardiac lesions is most likely to be present in this woman? A Bicuspid aortic valve B Coronary artery thrombosis C Left atrial myxoma D Mitral valve stenosis E Pericardial effusion

D. Bouts of rheumatic fever can eventually lead to rheumatic mitral stenosis with left atrial enlargement. (B) Incorrect. There may be some degree of cardiac enlargement, including the left atrium, with the heart failure produced by ischemic heart disease, including myocardial infarction, but it is not marked, and valves are not scarred or stenotic as a consequence.

A 49-year-old woman had atrial fibrillation that was poorly controlled, even with amiodarone therapy. She suffered a 'stroke' and died. At autopsy, her 600 gm heart is noted to have a mitral valve with partial fusion of the leaflets along with thickening and shortening of the chordae tendineae. There is an enlarged left atrium filled with mural thrombus. Which of the following underlying causes of death is she most likely to have? A Systemic lupus erythematosus B Coronary atherosclerosis C Marantic endocarditis D Rheumatic heart disease E Cardiac amyloidosis

D The figure shows a large ventricular septal defect. By the age of 5 years, such an uncorrected defect causes marked shunting of blood from left to right, causing pulmonary hypertension (Eisenmenger complex). The left and right ventricular chambers undergo hypertrophy and some dilation, but the functioning of the cardiac valves is not greatly affected. In most cases, congenital heart disease is not an antecedent to ischemic heart disease. Nonbacterial thrombotic endocarditis most often occurs secondary to a hypercoagulable state in adults. Restrictive cardiomyopathy may occur from conditions such as amyloidosis or hemochromatosis.

A 5-year-old child is not as active as other children his age. During the past 8 months, the child has had multiple episodes of respiratory difficulty following exertion. On physical examination, his temperature is 37° C, pulse is 81/min, respirations are 19/min, and blood pressure is 95/60 mm Hg. On auscultation, a loud holosystolic murmur is audible. There are diffuse crackles over the lungs bilaterally, with dullness to percussion at the bases. A chest radiograph shows a prominent left heart border, pulmonary interstitial infiltrates, and blunting of the costodiaphragmatic recesses. The representative gross appearance of the child's heart is shown in the figure. Which of the following additional pathologic conditions would most likely develop in this child? A Aortic regurgitation B Coronary atherosclerosis C Nonbacterial thrombotic endocarditis D Pulmonary hypertension E Restrictive cardiomyopathy

E Cyanosis at this early age suggests a right-to-left shunt. Truncus arteriosus, transposition of the great arteries, and tetralogy of Fallot are the most common causes of cyanotic congenital heart disease. The cerebral lesion suggests an abscess as a consequence of septic embolization from infective endocarditis, which can complicate congenital heart disease. Atrial septal defect, patent ductus arteriosus, and ventricular septal defect initially lead to left-to-right shunts, though the shunt may reverse with development of pulmonary hypertension. Coarctation is not accompanied by a shunt and cyanosis. In most cases, a bicuspid valve is asymptomatic until adulthood, and there is no shunt.

A 5-year-old girl who is below the 5th percentile for height and weight for age has exhibited easily fatigability since infancy. On physical examination, she appears cyanotic. Her temperature is 37° C, pulse is 82/min, respirations are 16/min, and blood pressure is 105/65 mm Hg. Pulse oximetry shows decreased oxygen saturation. One month later, she has fever and obtundation. A cerebral CT scan shows a right parietal, ring-enhancing, 3-cm lesion. Which of the following congenital heart diseases is the most likely diagnosis? A Atrial septal defect B Bicuspid aortic valve C Coarctation of the aorta D Patent ductus arteriosus E Truncus arteriosus F Ventricular septal defect

B The findings point to pure right-sided congestive heart failure. Rarely, this can be caused by right-sided cardiac valvular lesions, such as tricuspid or pulmonic stenosis. Pulmonary hypertension resulting from obstructive lung diseases, such as emphysema or chronic bronchitis, most often caused from smoking cigarettes, is much more common. Primary pulmonary hypertension also can cause right-sided heart failure, but it is a much less common cause than obstructive lung diseases. Because acute myocardial infarction usually affects the left ventricle, left-sided heart failure would be more common in these patients. Chronic left-sided heart failure eventually can lead to right-sided heart failure.

A 50-year-old man has had increasing abdominal discomfort and swelling of his legs for the past 2 years. He has smoked cigarettes for 35 years. On physical examination, he has jugular venous distention, even when sitting up. The liver is enlarged and tender and can be palpated 10 cm below the right costal margin. Pitting edema is observed on the lower extremities. A chest radiograph shows bilateral diaphragmatic flattening, pleural effusions, and increased lucency of lung fields. Thoracentesis on the right side yields 500 mL of clear fluid with few cells. Which of the following is most likely to be the underlying disease in this patient? A Acute myocardial infarction B Chronic bronchitis C Primary pulmonary hypertension D Pulmonary valve stenosis E Tricuspid valve stenosis

D In the period immediately after coronary thrombosis, arrhythmias are the most important complication and can lead to sudden cardiac death. It is believed that, even before ischemic injury manifests in the heart, there is greatly increased electrical irritability predisposing to dysrhythmias. Myocardial rupture, valvular insufficiency from papillary muscle involvement, and pericarditis occur several days later. Another complication is a left ventricular aneurysm, a late complication of the healing of a large transmural infarction; a mural thrombus may fill an aneurysm and become a source of emboli. If portions of the coronary thrombus break off and embolize, they enter smaller arterial branches in the distribution already affected by ischemia. Valvular insufficiency from a ruptured papillary muscle would occur later in the course.

A 50-year-old man has sudden onset of severe substernal chest pain that radiates to the neck. On physical examination, he is afebrile, but has tachycardia, hyperventilation, and hypotension. No cardiac murmurs are heard on auscultation. Emergent coronary angiography shows a thrombotic occlusion of the left circumflex artery and areas of 50% to 70% narrowing in the proximal circumflex and anterior descending arteries. Which of the following complications of this disease is most likely to occur within 1 hour of these events? A Myocardial rupture B Pericarditis C Valvular insufficiency D Ventricular fibrillation E Thromboembolism

B CK activity begins to increase 2 to 4 hours after an MI, peaks at about 24 to 48 hours, and returns to normal within 72 hours. Troponin I levels begin to increase at about the same time as CK and CK-MB, but remain elevated for 7 to 10 days. Total CK activity is a sensitive marker for myocardial injury in the first 24 to 48 hours. CK-MB offers more specificity, but not more sensitivity. The risk for myocardial rupture is greatest from 4 to 7 days after transmural myocardial necrosis. This patient had an MI on the day of the shoulder pain. When he saw the physician on day 3, the CK levels had returned to normal, but troponin I levels remained elevated. Three days later, the infarct ruptured, and blood filled the pericardial cavity. Cardiac valves are essentially avascular and not subject to ischemic injury. Ventricular aneurysm formation is a late complication of a healed MI. Papillary muscles are at risk for rupture, just like the free wall, but the consequence would be acute valvular insufficiency, not hemopericardium. A transmural MI may lead to pericarditis, often with some accompanying pericardial effusion, but the acute event here in the time frame described suggests rupture.

A 50-year-old man with diabetes mellitus and hypertension has had pain in the left shoulder and arm for the past 12 hours. Over the next 6 hours, he develops shortness of breath, which persists for 2 days. On day 3, he visits the physician. On physical examination, his temperature is 37.1° C, pulse is 82/min, respirations are 18/min, and blood pressure is 160/100 mm Hg. Laboratory studies show total creatine kinase (CK) activity within reference range, but the troponin I level is elevated. He continues to experience dyspnea for the next 3 days. On day 7 after the onset of shoulder pain, he has a cardiac arrest and is resuscitated. Cardiac imaging now shows a large fluid collection around the heart. Which of the following complications has he most likely developed? A Aortic valvular perforation B Hemopericardium C Left ventricular aneurysm D Papillary muscle rupture E Pericarditis

B. Contraction band necrosis is an initial change as the myocardial fibers begin to die within the first day of onset of myocardial infarction. Neutrophils become more numerous following the first day.

A 51-year-old man has the sudden onset of substernal chest pain which radiates to his left arm and neck. He becomes light-headed and diaphoretic over the next 3 hours. He goes to the emergency room. On examination he is afebrile but has a heart rate of 96/minute with an irregular rhythm. Laboratory studies show an increased serum troponin I. Which of the following features would be most prominent by histopathologic examination of his myocardium at this point in time? A Macrophage infiltration B Contraction band necrosis C Neutrophilic infiltration D Capillary proliferation E Collagen deposition

B. Primary cardiac neoplasms are uncommon. Of these, the most common is myxoma. Atrial myxomas are more often on the left. Though benign, they can occlude the mitral valve and produce sudden loss of cardiac output. They may embolize small portions of themselves or thrombus formed over their surface.

A 51-year-old woman has had several syncopal episodes over the past year. Each episode is characterized by sudden but brief loss of consciousness. She reports no chest pain. On physical examination her vital signs show T 36.9°C, P 80/minute, RR 16/minute, and BP 110/75 mm Hg. She has no pedal edema. On brain MR imaging there is a 1.5 cm cystic area in the left parietal cortex. A chest radiograph shows no cardiac enlargement, and her lung fields are normal. Her serum total cholesterol is 165 mg/dL. Which of the following cardiac lesions is she most likely to have? A Cardiac amyloidosis B Left atrial myxoma C Tuberculous pericarditis D Mitral valve prolapse E Ischemic cardiomyopathy

D. Pericardial tumor and tuberculosis are the typical causes for a hemorrhagic pericarditis. (E) Incorrect. This may lead to a fibrinous pericarditis. (C) Incorrect. Rheumatic fever is associated with a fibrinous pericarditis.

A 53-year-old man has had malaise for the past 3 months. On physical examination he is afebrile. On auscultation of the chest, heart sounds are distant and there is a friction rub. An echocardiogram shows a pericardial fluid collection. A pericardiocentesis yields 10 mL of bloody fluid. Which of the following conditions is most likely to give rise to these findings? A Autoimmune disease B Chronic renal failure C Rheumatic fever D Metastatic carcinoma E Acute myocardial infarction

C. The findings suggest the rare arrhythmogenic right ventricular cardiomyopathy, which is inherited in an autosomal dominant pattern. There is thinning with fatty replacement, beginning in the right ventricle but eventually involving the left ventricle, unless a fatal arrhythmia occurs. (E) Incorrect. Viral myocarditis can lead to arrhythmias, but there is unlikely to be focal right ventricular involvement. (B) Incorrect. Ethanolism may lead to a dilated cardiomyopathy involving all four chambers. (A) Incorrect. Atherosclerosis is most likely to lead to ischemic heart disease with left venttricular involvement, and thinning following healing of a myocardial infarction would represent a ventricular aneurysm.

A 53-year-old woman has noted increasing dyspnea for the past 2 years. On examination she is afebrile. She has an irregular pulse. A chest radiograph shows an enlarged right cardiac silhouette and bilateral pleural effusions. Echocardiography shows thinning of the right ventricular wall with reduced ejection fraction. Which of the following is the most likely etiology for her cardiac disease ? A Atherosclerosis B Chronic alcohol abuse C Gene mutation D Hypertension E Viral infection

C The findings point to dilated cardiomyopathy (DCM) with both right-sided and left-sided heart failure. The most common toxin producing DCM is alcohol, and individuals with chronic alcoholism are more likely to have DCM than to have ischemic heart disease. Acetaminophen ingestion can be associated with hepatic necrosis and analgesic nephropathy. Cocaine can produce ischemic effects on the myocardium. Lisinopril is an angiotensin-converting enzyme inhibitor that is used to treat hypertension. Nicotine in cigarette smoke is a risk factor for atherosclerosis. Propranolol is a β-blocker that has been used to treat hypertension, and it may exacerbate bradycardia and congestive heart failure.

A 56-year-old man has experienced increased fatigue and decreased exercise tolerance for the past 2 years. On physical examination, his temperature is 37° C, pulse is 75/min, respirations are 17/min, and blood pressure is 115/75 mm Hg. On auscultation, diffuse crackles are audible. The abdomen is distended with a fluid wave, and there is bilateral pitting edema to the knees. A chest radiograph shows pulmonary edema, pleural effusions, and marked cardiomegaly. An echocardiogram shows mild tricuspid and mitral regurgitation and reduced right and left ventricular wall motion, with an ejection fraction of 30%. He experiences cerebral, renal, and splenic infarctions over the next year. Chronic use of which of the following substances has most likely produced these findings? A Acetaminophen B Cocaine C Ethanol D Lisinopril E Nicotine F Propranolol

D. He has had an acute myocardial infarction complicated by rupture. This is a typical complication about 3 to 7 days following the onset of infarction. 75% arterial narrowing is the point at which coronary occlusion becomes very serious with increased risk for acute coronary syndromes.

A 60-year-old man had chest pain and was hospitalized. On the first day of admission, his troponin I is elevated. A coronary angiogram revealed 75% stenosis of the anterior interventricular (left anterior descending) artery. Four days later he suddenly becomes worse, with marked hypotension. A pericardiocentesis is performed and returns 150 cc of bloody fluid. Which of the following microscopic findings is most likely to be present in his left ventricular myocardium at the time of this hypotensive episode? A Extensive transmural collagen deposition B Lymphocytic infiltrates C Coronary arterial dissection D Necrosis with neutrophils and macrophages E Interstitial edema and loss of myofiber cross striations

D Myxomatous mitral valve degeneration can be primary from a connective tissue disorder such as Marfan syndrome or secondary to chronic hemodynamic forces 179(later in life); the chordae tendineae become elongated and can rupture to produce acute valvular incompetence. Destructive vegetations occur with infective endocarditis, and develop over days to weeks. Dystrophic calcification in older persons can occur in the mitral annulus or aortic valve; the former is typically incidental and the latter may produce symptomatic stenosis. Fibrinoid necrosis is most typical of hyperplastic arteriolosclerosis, not cardiac valves. Rheumatic heart disease leads to valvular scarring with shortening and thickening of the chordae tendineae, not thinning and elongation.

A 65-year-old healthy woman has a check of her health status and the only finding is a midsystolic click on auscultation of the heart. Within 5 years she has increasing dyspnea. Echocardiography now shows mitral regurgitation from prolapse of a leaflet. Which of the following pathologic changes is most likely present in this valve? A Destructive vegetations B Dystrophic calcification C Fibrinoid necrosis D Myxomatous degeneration E Rheumatic fibrosis

E These findings are consistent with right-sided congestive heart failure leading to peripheral edema, body cavity effusions (pleural effusions in this case), passive congestion of the liver, and jugular venous distension. Pure right-sided failure is less common than left-sided failure, and the former most often follows pulmonary disease (cor pulmonale). Chronic obstructive pulmonary disease (COPD) is more common than restrictive lung disease, and smoking leads to COPD. Atrial myxomas are uncommon, more often on the left side of the heart, and may produce intermittent valvular obstruction. Essential hypertension is systemic and places a pressure load on the left side of the heart. Hyperlipidemia is a risk factor for ischemic heart disease that is more likely to involve the left side of the heart. Rheumatic heart disease may produce heart failure, but it is more often left-sided.

A 66-year-old man has had cough and worsening shortness of breath for 3 years. On examination, there is dullness to percussion at both lung bases and poorly audible breath sounds. On physical examination, pulse is 77/min and BP is 110/80 mm Hg. He does not have anginal pain. His liver span is increased to 14 cm. He has pitting edema to his knees. Jugular venous distention is noted to the angle of the jaw at 45-degree elevation of his head while lying down. Which of the following is most likely causing his heart disease? A Atrial myxoma B Essential hypertension C Hyperlipidemia D Rheumatic fever E Smoking

A. The uremia leads to exudation of fibrin onto the epicardial and pericardial surfaces. There is often accompanying fluid, and the term serofibrinous exudate may be used. (D) Incorrect. This is more typical for collagen vascular diseases.

A 66-year-old man has had increasing malaise for the past year. On physical examination auscultation of the chest reveals a friction rub. Laboratory studies show a serum urea nitrogen of 100 mg/dL and creatinine of 9.8 mg/dL. Which of the following forms of pericarditis is he most likely to have? A Fibrinous B Hemorrhagic C Purulent D Serous E Constrictive

C Fibrinous pericarditis leads to the rough, corrugated brownish surfaces of epicardium and reflected pericardial sac as shown, which is sometimes described as a "bread and butter" appearance (after dropping the buttered bread on the carpet). Friction between epicardial and pericardial surfaces yields the rub, which may disappear with fluid collection (serofibrinous pericarditis). The most common cause is uremia resulting from renal failure. Elevation of the anti-streptolysin O titer accompanies rheumatic fever. Acute rheumatic fever may produce fibrinous pericarditis, but rheumatic fever is uncommon at this age. An elevated renin level is seen in some forms of hypertension, but by itself does not indicate renal failure. 182Elevation of serum creatine kinase occurs in myocardial infarction. An acute myocardial infarction may be accompanied by a fibrinous exudate over the area of infarction, not the diffuse pericarditis seen in this patient. A positive ANA test result suggests a collagen vascular disease, such as systemic lupus erythematosus, more likely associated with a serous pericarditis (without extensive fibrinous exudate). Fibrinous pericarditis is unlikely the result of an infection, but a fibrinopurulent appearance could suggest bacterial infection.

A 68-year-old man has become increasingly lethargic and weak for the past 7 months. On physical examination, his temperature is 36.9° C, pulse is 70/min, respirations are 15/min, and blood pressure is 160/105 mm Hg. On auscultation of his chest, a friction rub is audible. There are no other remarkable findings. The representative gross appearance of the heart is shown in the figure. Which of the following laboratory findings is most likely to be reported for this patient? A Elevated serum anti-streptolysin O titer B Elevated plasma renin level C Increased blood urea nitrogen level D Increased serum CK-MB level E Positive ANA with "rim" pattern F Positive viral serology

F. The figure shows an enlarged and dilated heart with a large ventricular aneurysm with a thin wall and white fibrous endocardial surface. Such an aneurysm most likely results from weakening of the ventricular wall at the site of a prior healed myocardial infarction. Because of the damage to the endocardial lining, with stasis and turbulence of blood flow in the region of the aneurysm, mural thrombi are likely to develop. When detached, thrombi in the left side of the heart embolize to the systemic circulation and can cause infarcts elsewhere. An atrial myxoma is the most common primary cardiac neoplasm, but it is rare and is not related to ischemic heart disease. Cardiac rupture with tamponade is most likely to occur 5 to 7 days after an acute myocardial infarction. Constrictive pericarditis follows a previous suppurative or tuberculous pericarditis. Hypertrophic cardiomyopathy is not related to ischemic heart disease, but 50% of cases are familial and may be related to genetic mutations in genes encoding for cardiac contractile elements. Infective endocarditis is more likely to complicate valvular heart disease or septal defects

A 69-year-old man with metabolic syndrome had chest pain and an elevated serum troponin I level 1 year ago. He was treated in the hospital with anti-arrhythmic agents for 1 week. An echocardiogram showed an ejection fraction of 28%. He now has markedly reduced exercise tolerance. On physical examination, his temperature is 37° C, pulse is 68/min, respirations are 17/min, and blood pressure is 130/80 mm Hg. Diffuse crackles are heard on auscultation of the lungs. The representative gross appearance of his heart is shown in the figure. Which of the following complications of this disease is the patient most likely to develop? A Atrial myxoma B Cardiac tamponade C Constrictive pericarditis D Hypertrophic cardiomyopathy E Infective endocarditis F Systemic thromboembolism

B. Such pancreatic cancers can produce paraneoplastic syndromes and be associated with a hypercoagulable state (Trousseau's syndrome) with formation of marantic cardiac valvular vegetations.

A 69-year-old woman with a 7 kg weight loss over the past 6 months now has developed painless jaundice over the past 2 weeks. On physical examination she is afebrile. An abdominal CT scan shows a large mass involving the head of the pancreas, along with widespread nodules in the liver. Nodules are seen in both lungs by chest radiograph. Which of the following cardiac abnormalities is she most likely to develop? A Dilated cardiomyopathy B Non-bacterial thrombotic endocarditis C Acute fibrinous pericarditis D Endocardial fibrosis E Acute myocardial infarction

E So-called marantic vegetations may occur on any cardiac valve, but tend to be small and do not damage the valves. They have a tendency to embolize, however. They can occur with hypercoagulable states that accompany certain malignancies, especially mucin-secreting adenocarcinomas. Thrombosis can occur anywhere, but is most common in leg veins, predisposing to pulmonary thromboembolism. This paraneoplastic state is known as Trousseau syndrome. Calcific aortic stenosis occurs at a much older age, usually in the eighth or ninth decade, and produces obstruction but not embolism. Cardiac metastases are uncommon, and they tend to involve the epicardium; they do not explain embolism with cerebral infarction in this case. A metastatic tumor can encase the heart to produce constriction, but this is rare. Mural thromboses occur when cardiac blood flow is altered, as occurs in a ventricular aneurysm or dilated atrium, but persons with malignancies likely have no or minimal ischemic heart disease.

A 71-year-old woman has had a 10-kg weight loss accompanied by severe nausea and vomiting of blood for the past 8 months. On physical examination, she is afebrile. Laboratory studies show hemoglobin, 8.4 g/dL; platelet count, 227,100/mm3; and WBC count, 6180/mm3. Biopsy specimens obtained by upper gastrointestinal endoscopy show adenocarcinoma of the stomach. CT scan of the abdomen shows multiple hepatic masses. CT scan of the head shows a cystic area in the right frontal lobe. Her condition is stable until 2 weeks later, when she develops severe dyspnea. A chest CT scan shows areas of decreased pulmonary arterial attenuation. Which of the following cardiac lesions is most likely to be present in this woman? A Calcific aortic valvular stenosis B Constrictive pericarditis C Epicardial metastatic carcinoma D Left ventricular mural thrombosis E Nonbacterial thrombotic endocarditis

A The history of diabetes mellitus and the chest pain put ischemic heart disease at the top of the differential diagnosis list for this man, who has findings with both right and left ventricular failure and enlargement, suggesting ischemic cardiomyopathy. An elevated serum B-type natriuretic peptide (which is measured instead of atrial natriuretic peptide) is consistent with heart failure. Occlusive coronary atherosclerosis may lead to multiple infarctions, or may silently cause progressive myofiber loss, but the end stage is ischemic cardiomyopathy. Atrial mural thrombus formation can occur with aortic valve dysfunction and with dysrrhythmias. Myofiber disarray is characteristic for hypertrophic cardiomyopathy, which affects the interventricular septum preferentially and is usually symptomatic by young adulthood. Although rheumatic valvulitis with thickening may involve both the left and right sides of the heart, this is unusual, and it is not associated with coronary artery disease. Pericardial fluid collection may constrict heart motion, without an enlarged heart, and hemopericardium may acutely occur with ventricular rupture.

A 72-year-old man with poorly controlled diabetes mellitus has worsening exercise tolerance for 5 years. For the past year he has had chest pain with minimal exertion. On physical examination he has bilateral pulmonary rales and pitting edema of his legs. He has an irregular heart rate. A chest radiograph shows prominent right and left heart borders. Echocardiography shows decreased left ventricular ejection fraction (25%) with diminished wall motion. Laboratory studies show an elevated serum B-type natriuretic peptide. Which of the following pathologic findings is most likely present in this man? A Critical coronary stenosis B Left atrial mural thrombus C Hypertrophic cardiomyopathy D Mitral and tricuspid valve thickening E Pericardial fibrinohemorrhagic exudate

E Myocardial infarction results from occlusion of large coronary arterial branches, and in most cases an occluding thrombus is present. The posterior left ventricle and septum are supplied by the posterior descending artery. The left circumflex artery supplies the lateral left ventricular wall, whereas the left anterior descending artery supplies the anterior left ventricle. An aortic dissection that extends proximally may cause tamponade, compressing the heart, great vessels, and even coronary arteries, but this is much less likely a cause for myocardial infarction than atherosclerotic coronary arterial disease. The coronary sinus is where venous blood from the myocardium drains into the right atrium.

A retrospective study of myocardial infarction is performed to analyze patterns of cardiac injury. One pattern of injury involves the posterior left ventricular wall and septum. Which of the following pathologic abnormalities is most likely to produce this pattern? A Ascending aortic dissection B Left anterior descending arterial plaque rupture C Left circumflex arterial vasculitis D Right coronary sinus embolization E Right posterior descending arterial thrombosis

C Hemorrhagic pericardial effusion most commonly is caused by either tumor or tuberculosis. The most common neoplasm involving the heart is metastatic cancer, because primary cardiac neoplasms are rare. The most common primary sites are nearby—lung, breast, and esophagus. The skin lesion in this patient is likely to be a malignant melanoma, which tends to metastasize widely, including to the heart. Most cardiac metastases involve the epicardium/pericardium. (By convention, even though epicardial surfaces are often involved most severely, the term pericardial effusion is typically used when fluid is present, or pericarditis is used when inflammation is present.) A large effusion can cause tamponade, which interferes with cardiac motion. Calcific aortic stenosis leads to left-sided congestive heart failure, with pulmonary edema as a key finding. Coronary atherosclerosis may lead to myocardial infarction, which can be complicated by ventricular rupture and hemopericardium, but the level of troponin I in this case suggests that infarction did not occur. Rheumatic heart disease mainly affects the cardiac valves, but acute rheumatic fever can produce fibrinous pericarditis. Tuberculosis is unlikely in this case because no pulmonary lesions were seen on the radiograph.

A 73-year-old woman has had episodes of chest pain during the past week. She is afebrile. Her pulse is 80/min, respirations are 16/min, and blood pressure is 110/70 mm Hg. On auscultation of the chest, heart sounds seem distant, but the lung fields are clear. Neck veins are distended to the angle of the jaw, even while sitting. There is a darkly pigmented, irregular, 1.2-cm skin lesion on the right shoulder. A chest radiograph shows prominent borders on the left and right sides of the heart. Pericardiocentesis yields bloody fluid. Laboratory findings include a serum troponin I level of 0.3 ng/mL. Which of the following lesions is the most likely cause of these findings? A Calcific aortic stenosis B Coronary atherosclerosis C Epicardial metastases D Mitral valvulitis E Tuberculous pericarditis

A. These are classic findings for temporal arteritis, the most typical involvement with giant cell arteritis. Corticosteroid therapy typically produces a diminution in the symptoms. Biopsy of the artery can remove the offending site of inflammation and relieve symptoms (don't worry--there are collateral branches). Not treating this condition puts the patient at risk for involvement of other branches of the external carotid artery, the worst of which would be the ophthalmic branch. The elevation of the sed rate is way out of proportion to the extent and amount of inflammation in this one arterial segment.

A 74-year-old man has had increasingly severe headaches for 2 months, centered on the right. His vital signs include T 36.9°C, P 82/minute, RR 14/minute, and BP 130/85 mm Hg. There is a palpable tender cord-like area over his right temple. His heart rate is regular with no murmurs, gallops, or rubs. Pulses are equal and full in all extremities. A biopsy of this lesion is obtained, and microscopic examination reveals a muscular artery with luminal narrowing and medial inflammation with lymphocytes, macrophages, and occasional giant cells. He improves with a course of high-dose corticosteroid therapy. Which of the following laboratory test findings is most likely to be present with this man's disease? A Erythrocyte sedimentation rate of 110 mm/hr B Rheumatoid factor titer of 80 IU/mL C HDL cholesterol of 15 mg/dL D Anti-double stranded DNA titer of 1:1024 E pANCA titer of 1:160

E. Treponema pallidum is the organism that causes syphilis. Tertiary syphilis may have neurologic, joint, and cardiovascular complications. The endaortitis of the vasa vasora affects the media of the aorta, leading to buckling of the intimal surface in a 'tree bark' pattern, and aneurysmal dilation, including the aortic root, causing aortic regurgitation. This happens decades following initial infection.

A 77-year-old man with decreasing mental function has developed increasing dyspnea for the past 3 years. On physical examination he has a diastolic murmur. A chest CT scan shows an enlarged heart and prominent aorta. He dies from complications of pneumonia. At autopsy, the thoracic aorta is aneurysmally dilated. A microscopic section of the aorta shows chronic inflammation and luminal narrowing of vasa vasora. There is disruption of the aortic medial elastic fibers. Which of the following conditions is most likely to cause these findings? A Hypercholesterolemia B Marfan syndrome C Polyarteritis nodosa D Takayasu arteritis E Tertiary syphilis F ANCA-associated vasculitis

D This is the infamous "paradoxical embolus" that has appeared far more often in question sets than in real life. She started with thrombophlebitis that led to pulmonary embolism, but there must be an explanation for the "stroke" that then occurred. Pulmonary emboli can obstruct the pulmonary arterial circulation, raising right atrial pressure, and opening a patent foramen ovale that normally remains closed because of higher left atrial pressure. The remaining choices do not explain pulmonary thromboembolism. A left atrial myxoma can embolize to the brain; lesions of endocarditis are most often on the left side of the heart and could produce cerebral emboli; a ventricular aneurysm is virtually always on the left side of the heart because it results from a healed infarction, and can be filled with mural thrombus that can embolize.

A 77-year-old woman fell and fractured her ankle. She has spent most of her time in bed for the past 16 days. She develops sudden chest pain, dyspnea, and diaphoresis. On examination she has left thigh swelling and tenderness. A chest CT shows areas of decreased attenuation in the right and left pulmonary arteries. A day later she has difficulty speaking. MR angiography shows focal occlusion of a left middle cerebral artery branch. Which of the following cardiac abnormalities is she most likely to have? A Atrial myxoma B Infective endocarditis C Nonbacterial thrombotic endocarditis D Patent foramen ovale E Ventricular aneurysm

B. Libman-Sacks endocarditis is most often seen in patients with autoimmune diseases such as systemic lupus erythematosus, and SLE often has renal complications with glomerulonephritis.

A clinical study is performed to document complications in persons with glomerulonephritis and with laboratory studies showing an elevated antinuclear antibody and anti-ds-DNA titer. Which of the following cardiac abnormalities is most likely to be present? A Pancarditis B Libman-Sacks endocarditis C Hemorrhagic pericarditis D Lipofuscin deposition E Coronary artery vasculitis

D This boy developed acute left ventricular failure, an uncommon but serious complication of acute rheumatic fever. Pancarditis with pericarditis, endocarditis, and myocarditis develop during the acute phase. Myocarditis led to dilation of the ventricle so severe that the mitral valve became incompetent. Rheumatic heart disease is now uncommon, and the number of children that require prophylactic antibiotic therapy to prevent just one case is >10,000. Chronic inflammatory conditions may produce reactive systemic amyloidosis, but this is unlikely to occur given the limited and episodic nature of the streptococcal infection that causes rheumatic heart disease. Fibrinous pericarditis can produce an audible friction rub, but it is not constrictive, and the amount of fluid and fibrin are not great, so no tamponade occurs. Myocardial necrosis associated with myocarditis is patchy, and the ventricle does not rupture to produce tamponade. Fibrosis and fusion of the mitral valve leaflets develop over weeks to months and indicate chronic rheumatic valvulitis. Verrucous vegetations are small and may produce a murmur, but they do not interfere greatly with valve function and do not tend to embolize.

An 11-year-old boy had a sore throat, no cough, tonsillar exudates, and 38.3° C fever 3 weeks ago, and a throat culture was positive for group A β-hemolytic Streptococcus. On the follow-up examination, the child is afebrile. His pulse is 85/min, respirations are 18/min, and blood pressure is 90/50 mm Hg. On auscultation, a diastolic mitral murmur is audible, and there are diffuse rales over both lungs. Over the next 2 days he has several episodes of atrial fibrillation accompanied by signs of acute left ventricular failure. Which of the following pathologic changes occurring in this child's heart is most likely to be the cause of the left ventricular failure? A Amyloidosis B Fibrinous pericarditis C Mitral valve fibrosis D Myocarditis E Tamponade F Verrucous endocarditis

B Reduced cardiac chamber compliance is a feature of the restrictive form of cardiomyopathy. Cardiac amyloidosis may be limited to the heart (so-called senile cardiac amyloidosis derived from transthyretin protein) or may be part of organ involvement in systemic amyloidosis derived from serum amyloid-associated (SAA) protein or, in multiple myeloma, derived from light chains (AL amyloid). Incidental isolated atrial deposits of amyloid are derived from atrial natriuretic peptide. Myocardial fiber dysfunction markedly reduces ventricular compliance. Dynamic left ventricular outflow obstruction is characteristic of hypertrophic cardiomyopathy. Valvular insufficiency of mitral and tricuspid valves can occur with dilated cardiomyopathy, which also reduces contractility and ejection fraction with increased end-systolic volume.

An 86-year-old man has had increasing dyspnea and reduced exercise tolerance for the past 7 years. On physical examination, he is afebrile and has a blood pressure of 135/85 mm Hg. An irregularly irregular heart rate averaging 76/min is audible on auscultation of the chest. Crackles are heard at the bases of the lungs. A chest radiograph shows mild cardiomegaly and mild pulmonary edema. Echocardiography shows slight right and left ventricular wall thickening with reduced left and right ventricular wall motion, reduced left ventricular filling, and an ejection fraction estimated to be 25%. An endomyocardial biopsy specimen shows amorphous pink-staining deposits between myocardial fibers, but no inflammation and no necrosis. Echocardiography would most likely show which of the following functional cardiac disturbances? A Dynamic obstruction to ventricular outflow B Impaired ventricular diastolic filling C Increased end-systolic volume D Mitral and tricuspid valvular insufficiency E Reduced ejection fraction

E This shunt results from abnormal confluence of pulmonary veins leading to the right atrium (or systemic veins), and not the left. Obstruction is often present, as in this case, with pulmonary congestion. Deoxygenated systemic and oxygenated pulmonary venous blood mix in the right atrium. There must be an atrial septal defect for blood to reach the left atrium, but an ASD by itself does not explain this case. A coarctation is not associated with cyanosis; a preductal coarctation is life-threatening. Patent ductus arteriosus is a 175left-to-right shunt without cyanosis. Tetralogy of Fallot can lead to cyanosis, but mixing of blood occurs at an overriding aorta.

Following an uncomplicated pregnancy, a term infant appears normal at birth, but at 1 day of life the infant develops respiratory distress. On physical examination the infant has tachypnea, tachycardia, and cyanosis. There is an S1 ejection click and a split S2 with prominent P sound. A radiograph shows normal heart size but prominent hilar vascular markings. Echocardiography shows a small left atrium, large right atrium, normally sized ventricles, widely patent foramen ovale, and normally positioned aorta and pulmonary trunk. What type of congenital heart disease does this infant most likely have? A Atrial septal defect B Coarctation of the aorta, preductal type C Patent ductus arteriosus D Tetralogy of Fallot E Total anomalous pulmonary venous connection