Clinical Pathophysiology Chapter 10 Review
Most cases of myocarditis in the US are viral in origin. What are the most common pathogens responsible?
Coxsackieviruses A and B, echovirus
In most cases of chronic cardiac decompensation, patients present with ___________________________
biventricular CHF encompassing the clinical syndromes of both right sided and left sided heart failure
What type of valvular heart disease is a common degenerative age-related lesion?
calcific aortic stenosis - valve fibroblasts and valve mitral fibroblasts decrease and calcic is building up during this most common congenital disease is bicuspid aortic valve stenosis is failure of a valve to open completely, obstructing forward flow, and insufficiency results from a failure of a valve to close completely thereby allowing regurgitation (backflow of blood)
List the classifications of vascular tumors
capillary hemangioma, lymphangioma, and glomus tumor are benign vascular tumors angiosarcoma is a malignant tumor hemangioendotheliomas are low grade malignant tumors
Define systolic dysfunction
cardiac muscle contracts weakly and the chambers cannot empty properly, usually a consequence of ischemic heart disease or hypertension
What event happens during ventricle systole?
opening of semilunar valves (pulmonary on the right and aortic on the left)
What is the SA node?
pacemaker of the heart
Describe Eisenmenger Syndrome
prolonged left to right shunting with volume and pressure overloads eventually causes pulmonary hypertension and secondarily right sided pressure that exceed those on the left, at the point reversal of blood flow occurs with resultant right to left shunting, and development of cyanosis such reversal of flow and shunting of unoxygenated blood into the systemic circulation is called Eisenmenger Syndrome
Formation of thrombi and emboli arising from these thrombi account for the common and the most serious complications following __________________
prosthetic valve implantation
What is the cardiac cycle?
rhythmic pumping of heart that is broken into two parts: systole: ventricle of heart contracts diastole: ventricle of heart relaxes
What are clinical manifestations of right ventricular failure?
right atrial and ventricular dilation, hypertrophy, congestive hepatomegaly, congestive splenomegaly, peripheral edema, pleural effusion, ascites
What usually causes right sided heart failure?
right sided is usually a consequence of left sided heart failure, pressure increase in pulmonary circulation inevitably produces an increased burden on the right side of the heart
Carcinoid tumors elaborate bioactive products that can cause cardiac lesions. What are these products?
serotonin, kallikrein, bradykini, histamine, prostaglandins, and tachykinins p and K lesions are usually located on the right heart valves on endocardium
What are two intracellular bacteria that kill the host cell through rapid replication and lysis?
shigella and e.coli
Name the two categories of hypertensive heart disease
systemic (left sided) hypertensive heart disease pulmonary (right sided) heart disease - cor pulmonale
Most cases of congestive heart failure are due to _______________
systolic dysfunction
What are the most common causes of left sided heart failure?
the most common cause of left sided is ischemic heart disease, systemic hypertension, mitral or aortic valve disease, and primary diseases of the myocardium
Endomyocardial catheter biopsy is the only reliable means of diagnosing ______________
transplantation rejection in transplanted hearts
Congenital hypertrophic cardiomyopathy can result from the mutation of the gene encoding _______________
troponin T, troponin I, a-tropomyosin, myosin-binding protein, B-myosin heavy chain
What is currently the best biochemical indicator of a myocardial infarction?
troponin t there are multiple indicators, this is just the best one
Describe bacillary angiomatosis
typically found in AIDS patients and caused by Bartonella henselae
Calcific aortic valve stenosis causes _______________ to flow
obstruction
Describe mitral valve prolapse and its primary form
one or both valves are enlarged
Fevers, murmurs, embolic phenomena, and the ultrasonographic findings suggest the diagnosis of _______________
bacterial endocarditis
At what age of the embryo's life does the heart begin to pump blood?
22nd day of gestation
Cardiovascular disease accounts for what percent of all deaths in the United States?
40%
What percentage of cases will an angiography reveal a thrombus occulting the coronary artery after the onset of infarction?
90% within 4 hours
What is an adaptive response of the heart to systemic hypertensive heart disease?
hypertrophy
What are three mechanisms the cardiovascular system uses to compensate for reduced myocardial contractility or increased hemodynamics burden?
Frank-Starling mechanism, activation of neurohumoral systems (release of epinephrine and other chemicals), myocardial structural changes (increase in myocyte hypertrophy and fibrosis)
Name the bacterial agents in the low virulence HACEK group of oral cavity commensals associated with infective endocarditis?
Haemophilus, actinobacillus, cardiobacterium, eikenella, kingella
Describe endocarditis of systemic lupus erthematosus
Libman-sacks disease endocarditis that occurs in SLE and in antiphospholipid syndrome, presumably due to immune complex deposition
Describe myocardial infarction as well as the clinical features of a class MI
MI also referred to as a "heart attack" is necrosis of heart muscle resulting from ischemia, severe crushing chest pain radiating to the neck, jaw, epigastrium, or left arm, weak or rapid pulse, diaphoresis, nausea, dyspnea, myoglobin, cardiac troponins T and I, creatine kinase, and lactate dehydrogenase found in blood
Describe nonbacterial thrombotic endocarditis
Marantic endocarditis
Describe the 3 types of congenital atrial septal defects
Ostium Secundum ASDs account for 90% of ASDs: smooth walled defects near the foramen ovale usually without other associated cardiac abnormality (most common) Ostium Primum ASDs accounts for 5% of ADSs: occurs in the lowest part of the atrial septum and can be associated with mitral and tricuspid valve abnormalities Sinus Venosus ASDs accounts for 5% of ASDs: located high in the atrial septum and often are associated with anomalous drainage of the pulmonary veins into the right atrium or superior vena cava
Describe course of impulse travel through the cardiac conduction system
SA node impulse-> AV node impulse -> AV bundle impulse (bundle of his) -> purkinje fibers impulse
What protozoan, also associated with Chagas disease, causes myocarditis in most those infected with it?
Trypanosoma cruzi
Describe the mechanism of cardiac cell contraction
action potential induced by pacemaker cells in SA and AV nodes action potentials travel between sarcomeres
Describe the two types of infective endocarditis and the most common bacteria associated with each
acute endocarditis: happens quickly, caused by highly virulent organisms (staphylococcus aureus) typically seeding a previously normal valve to produce necrotizing subacute endocarditis: fast, but not as fast, typically caused by moderate to low virulence organisms (streptococcus viridians) seeding an abnormal or previously injured valve
Describe rheumatic fever
acute inflammatory disease that occurs in children after group A beta-hemolytic streptococcal (not staphococcal) usually pharyngitis
Describe Tetralogy of Fallot
cardinal features: right ventricular outflow tract obstruction (pulmonary stenosis), right hypertrophy, VSD, overriding of the VSD by the aorta, the hemodynamic consequences of tetralogy fallot are right-to-left shunting, decreased pulmonary blood flow, and increased aortic volumes the clinical severity largely depends on the degree of the pulmonary outflow obstruction
What are clinical manifestations of left ventricular failure?
cardiomegaly, tachycardia, a third heart sound (S3), fine rales at the lung bases, pulmonary congestion and edema, left atrial dilation, atrial fibrillation, decreased renal perfusion
What is the etiology of serious pericarditis?
cause is usually unknown, it is characteristically non-bacterial
Describe infantile coarctation
characterized by circumferential narrowing of the aortic segment between left subclavian artery and the ductus arterioisus
Chronic cor pulmonale is a result of what specific factors?
chronic right ventricular pressure overload
Myocyte hypertrophy increase the content of contractile proteins at the expense of what?
compliance, impairing diastolic filling while increasing oxygen demand
Name some causes of acquired valvular heart disease?
degeneration - calcification inflammatory processes - rheumatic heart disease infection - infective endocarditis changes secondary to myocardial disease
Describe ischemic heart disease and list clinical manifestations
diagnose by listening to any heart that has abnormal rhythm (dysrhythmia) caused by myocardial ischemia clinical manifestations include angina pectoris, acute myocardial infarction, chronic IHD with CHF, and sudden cardiac death
What are the three main functional and pathologic patterns of cardiomyopathies?
dilated, hypertrophic, restrictive
What is usually the the earliest and most significant symptom of left sided heart failure?
dyspnea
What is seen microscopically in the acute phase of of rheumatic fever?
fibrinoid necrosis, ashcoff bodies, anitschkow cells - "caterpillar cells"
Which of the following is the most common cardiac disease encountered in patients who have rheumatoid arthritis?
fibrinous pericarditis often progresses to adhesive pericardial fibrosis, adhesive pericardial fibrosis is the most common heart disease found in patients who have longstanding rheumatoid arthritis
The most common location of atrial septal defects is in the _____________
fossa ovalis, the original site of the foramen secundum
Define congestive heart failure and what it is caused by
generally defined as heart failure, occurs when the heart cannot generate sufficient output to meet the metabolic demands of the tissues, caused by many conditions that damage cardiac muscle such as: coronary artery disease, heart attack, cardiomyopathy, and other conditions that overwork the heart (high blood pressure, valve disease, thyroid disease, kidney heart disease, diabetes, or heart defects present at birth) myocytes in heart hypertrophy and increase in fibrosis
Cardiac output
heart rate x stroke volume x volume of blood being pumped by the heart per minute
The central circulation contains blood that is in what?
heart, lungs (pulmonary blood vessels)
Does compensated heart failure usually lead to decompensated heart failure?
in compensated heart failure, the dilated ventricle is able to maintain cardiac output via the frank starling mechanism, this ventricular dilation comes at the expense of increased wall tension and amplifies the oxygen requirements of the myocardium, eventually the muscle fails and is longer able to propel sufficient blood to meet needs of tissues and the patients develops decompensated heart failures
Describe the Frank-Starling mechanism
increased end-diastolic filling volumes dilate the heart and cause increase cardiac myofiber stretching, these lengthened fibers contract more forcibly, thereby increasing cardiac output the larger the stretch of the muscle - the more force it gives
Describe blood flow vena cava
inferior vena cava: carries deoxygenated blood from the lower half of the body to the right atrium of the heart clinical significance: blockage of inferior vena cava is associated with DVT (blood clot) superior vena cava: receives from from upper limbs, eyes, and neck, behind the lower border of the first right costal cartilage clinical significance: obstruction can lead to enlarged veins in the head and neck and may also cause breathlessness cough, chest pain, and difficulty swallowing
Describe angina pectoris and the variants
intermittent chest pain caused by transient, reversible myocardial ischemia, the pain is a consequence of the ischemia-induced release of adenosine, bradykinin, and other molecules that stimulate the autonomic afferents typical or stable angina: prinzmetal or variant angina: unstable angina:
List 5 manifestations of arrhythmia
irregular rhythm can start in any cell in the heart tachycardia (fast heart rate), bradycardia (slow heart rate), irregular rhythm with normal ventricular contraction, chaotic depolarization without functional ventricular contraction (ventricular fibrillation), no electrical activity at all (asystole)
What is the most common cause of sudden death in adults?
ischemic heart disease caused by thrombotic occlusion of atherosclerotic coronary arteries, atherosclerotic coronary heart disease
Describe the two periods of ventricular systole
isovolumetric contraction period: AV and semilunar valves are closed, ventricles begin to contract, ventricular muscle initially shortens only a little, but intraventricular pressure rises sharply ventricular ejection period: AV valves are closed and semilunar valves are open, pressure in left and right ventricle exceeds pressures in aorta and pulmonary artery, ejection is rapid at first, slowing down as systole progresses
What are two types of prosthetic heart valves?
mechanical valves: rigid, synthetic bioprosthetic valves: chemically fixed animal tissue
Rheumatic endocarditis is still the most common cause of _____________
mitral stenosis (accounting for 99% of all cases)
Define diastolic dysfunction
muscle cannot relax sufficiently to permit ventricular filling, such as massive left ventricular hypertrophy, myocardial fibrosis, amyloid deposition, or constrictive pericarditis
Describe the Jones criteria
used to diagnose rheumatic fever the constellation of findings to diagnose rheumatic fever, erythema marginatum - skin rash, Sydenham chorea - purposeless movement, carditis, subcutaneous nodules and/or migratory large joint polyarthritis Duke criteria: describes infective endocarditis
___________________ is the most common cause of death within the first few hours after coronary artery occulusion
ventricular fibrillation