BRS Pathology 10 - The Heart
The answer is E. This is a case of acute rheumatic fever. Acute rheumatic fever manifests most commonly in patients 5 to 15 years of age with migratory polyarthritis, pancarditis, subcutaneous nodules, erythema marginatum, and Sydenham chorea. Decades later, severe valvular disease, often manifesting as mitral stenosis, may develop as a feature of rheumatic heart disease. In this chronic stage of rheumatic disease, fibrotic valves may become stenotic, insufficient, or both, but much more commonly, progression to cardiac valve complication does not occur.
A 10-year-old boy presents with migratory polyarthritis involving several large joints, fever, and malaise. Physical examination reveals a new heart murmur and friction rub on auscultation, and a painless nodule is detected on the extensor surface of the elbow. He had a severe sore throat approximately 2 weeks ago, apparently recovering without antibiotic therapy. The anti- streptolysin O (ASO) titer is elevated. Which of the following describes the most likely outcome for this patient? (A) Development of mitral valve stenosis over many months to years (B) Development of mitral valve stenosis over the next few months (C) Increasing severity of the current symptoms and findings over the next few decades (D) Persistence of the current symptoms and signs over the patient's lifetime (E) Total recovery after 1 to 2 months with no further complications or sequelae
The answer is D. In the tetralogy of Fallot, the characteristic lesions include ventricular septal defect, overriding aorta, pulmonary valve stenosis, and right ventricular hypertrophy. The pulmonary stenosis and overriding aorta cause increased right ventricular pressure and lead to right-to-left shunting. Cyanosis, which occurs when the arterial concentration of reduced hemoglobin exceeds 5 mg/mL, is seen with a right-to-left shunt, in which venous blood gains direct access to the arterial circulation. In contrast, patent ductus arteriosus, atrial septal defect, and ventricular septal defect are associated with left-to-right blood flow.
A 3-year-old boy presents with cyanosis and shortness of breath that develops when he plays with friends. According to his mother, the boy was born cyanotic. The boy is very small and short for his age, and he squats on the floor next to his mother. Chest radiography reveals a boot-shaped heart, normal heart size, and a right aortic arch. Echocardiography reveals a large ventricular septal defect with an overriding aorta, pulmonary stenosis, and right ventricular hypertrophy. Which of the following is the most likely diagnosis? (A) Coarctation of the aorta (B) Patent ductus arteriosus (C) Rheumatic heart disease (D) Tetralogy of Fallot (E) Transposition of the great vessels
The answer is B. Cardiomyopathies are noninflammatory myocardial disorders that are not associated with coronary artery obstruction, hypertension, valvular disease, congenital heart disease, or infectious disease. They are most often characterized by otherwise unexplained ventricular dysfunction, such as cardiac failure, ventricular enlargement, or ventricular arrhythmias.
A 42-year-old man is seen because of a long history of slowly developing congestive heart failure. His blood pressure is normal. Coronary artery angiography reveals no vascular disease. No heart murmurs are heard. The white blood cell count, differential, and erythrocyte sedimentation rate are normal. The most likely diagnosis is (A) carcinoid heart disease. (B) cardiomyopathy. (C) coarctation of the aorta. (D) constrictive pericarditis. (E) myocardial infarction.
The answer is A. This is a case of paradoxical embolism, which denotes the passage of an embolus of venous origin into the arterial circulation, by way of a right-to-left shunt (e.g., atrial septal defect or patent foramen ovale). Ordinarily, atrial septal defects result in a left-to-right shunt across the atrial septum, but over time may develop into a rightto-left shunt. The likelihood of right-to-left passage of an embolus is often enhanced by pulmonary hypertension, sometimes secondary to pulmonary thromboembolism.
A 50-year-old man presents with sudden weakness in his left leg. He has felt well lately and has no past medical history of coronary artery disease, hyperlipidemia, or hypertension, and no family history of myocardial infarction or stroke. Physical examination reveals motor weakness in the left leg, with no other neurologic deficits, and no cardiac murmur. Magnetic resonance imaging of the brain demonstrates a small ischemic infarct in the arterial distribution of the brain correlating with motor control of the left leg. Angiography and echocardiography reveal normal coronary arteries, normal valves with no vegetations, and a small right-to-left shunt. Which of the following is most likely associated with this scenario? (A) Atrial septal defect (B) Bacterial endocarditis (C) Nonbacterial thrombotic (marantic) endocarditis (D) Tetralogy of Fallot (E) Ventricular septal defect
The answer is A. Congestive or dilated cardiomyopathy is the most common form of cardiomyopathy. It is characterized by four-chamber hypertrophy and dilation as well as right- and left-sided severe heart failure. In some cases, congestive (dilated) cardiomyopathy may be associated with alcoholism, thiamine deficiency, or prior myocarditis.
A 53-year-old woman presents with dyspnea on exertion, orthopnea, paroxysmal nocturnal dyspnea, edema in the legs and feet, and fatigue. She has no history of angina, other signs of coronary artery disease, hypertension, or valvular disease. Echocardiography reveals cardiomegaly, with four-chamber hypertrophy and dilation. Which of the following is the most likely diagnosis? (A) Congestive or dilated cardiomyopathy (B) Hypertrophic cardiomyopathy (C) Myocarditis (D) Restrictive cardiomyopathy
The answer is D. This is a classic case of stable angina, which is chest pain that is precipitated by exertion but relieved by rest. Stable angina is due to atherosclerosis of the coronary arteries. This patient has risk factors for ischemic heart disease (IHD) (e.g., cigarette smoking, hypertension, hyperlipidemia, diabetes, family history of IHD/coronary artery disease). Prinzmetal angina is intermittent chest pain at rest, and unstable angina is prolonged chest pain at rest.
A 55-year-old woman presents with complaints of chest pain. She states that the chest pain predictably occurs when she climbs four flights of stairs to reach her apartment or when she has been jogging for more than 10 minutes. She is particularly concerned because her mother died of a myocardial infarction at 50 years of age. Which of the following best describes this patient's state? (A) Arrhythmia (B) Myocardial infarction (C) Prinzmetal angina (D) Stable angina pectoris (E) Unstable angina pectoris
The answer is D. Myxoma of the heart, although rare, is the most common primary cardiac tumor. Because of the jelly-like appearance and myxoid histology similar to that of some organized thrombi, the neoplastic nature of this lesion was debated for many years; however, it is now generally believed that myxoma is a true neoplasm. The most common location of myxoma is in the left atrium. Due to its location, complications may develop due to physical obstruction of blood flow through the mitral valve, resulting in symptoms of congestive heart failure. Note that while angiosarcoma is the most common primary cardiac malignancy, it is not the most common primary cardiac tumor.
A 56-year-old woman presents with dyspnea on exertion, orthopnea, paroxysmal nocturnal dyspnea, and pulmonary edema. She also presents with severe dizziness and syncope, fatigue, weight loss, and arthralgias. After undergoing several tests, she is diagnosed with a primary heart tumor that is causing a "ball-valve obstruction" of her mitral valve. Which of the following is the most likely tumor? (A) Fibroma (B) Leiomyoma (C) Lipoma (D) Myxoma (E) Rhabdomyoma
The answer is A. This is a case of syphilitic (luetic) aortitis. In syphilitic aortitis, the elastica of the aorta undergoes calcification and is replaced by fibrous tissue, resulting in dilation of the ascending aorta and separation of the aortic valve commissures, with resultant aortic insufficiency. Thus, echocardiography and computed tomography of the heart reveal calcification in a linear pattern along the ascending aorta, calcification in the coronary arteries (leading to anginal symptoms), and aortic valvular insufficiency.
A 60-year-old man presents with angina. He has no past medical history of heart disease. On questioning, the patient reveals that he had repeated sexually transmitted diseases in the past, including a painless chancre (a hard, round sore) on his penis, for which he never sought medical attention. Rapid plasma reagin (RPR), Venereal Disease Research Laboratory (VDRL) slide test, and fluorescent treponemal antibody (FTA) serologic tests (indicative of syphilis infection) are positive. Echocardiography and computed tomography of the heart are performed. The history of untreated syphilis suggests that these tests will most likely detect which of the following abnormalities? (A) Aortic valvular insufficiency and linear calcification along the ascending aorta (B) Bicuspid aortic valve with aortic stenosis (C) Large valvular vegetations from bacterial endocarditis (D) Right-sided heart failure from the carcinoid syndrome (E) Small fibrin deposits on the mitral valve from nonbacterial thrombotic (marantic) endocarditis
The answer is D. Rupture of the left ventricle, a catastrophic complication of acute myocardial infarction, usually occurs when the necrotic area has the least tensile strength, about 4 to 7 days after an infarction, when repair is just beginning. The anterior wall of the heart is the most frequent site of rupture, usually leading to fatal cardiac tamponade. Internal rupture of the interventricular septum or of a papillary muscle may also occur. The risk of arrhythmia is greatest within the first 6 hours after myocardial infarct. Arrhythmias are the most important early complication of acute myocardial infarction, accounting for almost 50% of deaths shortly after myocardial infarction. Myocardial, or pump, failure and mural thrombosis are other complications that may develop as a result of permanent damage to the heart after infarct. Ventricular aneurysms may develop in the fibrotic scar within 3-6 months after myocardial infarct.
A 60-year-old-man is discharged after being observed in the hospital for 4 days following a myocardial infarction. He returns to his normal activities, which include sedentary work only. This point in time following a myocardial infarct is noteworthy for the special danger of which of the following? (A) Arrhythmia (B) Mural thrombosis (C) Myocardial (pump) failure (D) Myocardial rupture (E) Ventricular aneurysm
The answer is B. The term cor pulmonalerefers to right ventricular hypertrophy caused by pulmonary hypertension secondary to disorders of the lungs or pulmonary vessels. Other causes of right ventricular hypertrophy and failure, such as valvular disease, congenital defects, and left-sided heart failure, are precluded by this definition. Therefore, although in general, the most common cause of right-sided heart failure is left-sided heart failure, cor pulmonale with right-sided heart failure is due to an intrinsic disease originating in the lungs. Constrictive pericarditis can clinically mimic right-sided heart failure but is entirely unrelated to cor pulmonale.
A 64-year-old woman presents with dependent peripheral edema in her ankles and feet. She has long-standing chronic obstructive lung disease and a long history of cigarette smoking. Further investigation reveals that she has cor pulmonale with right-sided heart failure. Which of the following is the most likely cause of the right-sided heart failure in this patient? (A) Constrictive pericarditis (B) Disease of the lungs or pulmonary vessels (C) Left-sided heart failure (D) Pulmonary infundibular or valvular stenosis (E) Systemic hypertension
The answer is D. Nonbacterial thrombotic endocarditis, or marantic endocarditis, has been associated with a variety of wasting diseases and is observed most often in patients with cancer.
A 70-year-old woman has a long history of metastatic colon cancer, and she donates her body for use in medical school anatomy courses. At death, the body is emaciated and cachectic, and gross dissection reveals small fibrin deposits arranged around the line of closure of the leaflets of the mitral valve. The valvular lesions most likely represent (A) bacterial endocarditis. (B) endocarditis of the carcinoid syndrome. (C) Libman-Sacks endocarditis. (D) nonbacterial thrombotic (marantic) endocarditis. (E) rheumatic endocarditis.
The answer is C. The most common cause of death that occurs during acute rheumatic fever is cardiac failure secondary to myocarditis.
A 9-year-old girl is diagnosed with acute rheumatic fever. Instead of recovering as expected, her condition worsens, and she dies. Which of the following is the most likely cause of death? (A) Central nervous system involvement (B) Endocarditis (C) Myocarditis (D) Pericarditis (E) Streptococcal sepsis
The answer is A. The figure illustrates an Aschoff body, the characteristic lesion of rheumatic fever. This myocardial lesion is most often oval in shape and characterized by swollen, fragmented collagen and fibrinoid material and by characteristic large mesenchymal cells (Anitschkow myocytes) and multinucleated cells (Aschoff cells). Sydenham chorea is a major manifestation of rheumatic fever.
The myocardial lesions shown in the figure were observed at the autopsy examination of a pediatric patient who died after a short illness. During life, which of the following manifestations of his illness was most likely? (A) Chorea (B) Systemic embolization (C) Systemic lupus erythematosus (D) Unstable angina (E) Wasting diseases
The answer is A. By 24 hours well-developed microscopic changes of coagulative necrosis can be detected in infarcted tissue. There is loss of nuclei in cells and infiltration of neutrophils into tissue.
Yesterday, a 60-year-old man presented to the emergency department with dyspnea, diaphoresis, and crushing substernal chest pain that radiated to his neck and left arm. When asked to describe the pain, he put his fist to the center of his chest and stated that it felt "as if someone is squeezing my heart." An electrocardiogram demonstrated changes consistent with myocardial infarction, and serum troponin I levels were elevated. If the patient unexpectedly dies today, which of the following would almost certainly be found on histologic examination of the affected myocardium? (A) Coagulative necrosis with neutrophil infiltration (B) Fibrotic tissue replacing infarcted tissue (C) No histologic changes (D) Slight swelling of tissue and change of color (E) Young fibroblasts and new vessels growing into the infarcted tissue
