Clinical Pathophysiology Unit 3 Review

In most cases of chronic cardiac decompensation, patients present with ___________________________

Biventricular congestive heart failure (symptoms of both right and left-sided heart failure)

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

Most cases of myocarditis in the US are viral in origin. What are the most common pathogens responsible?

Coxsackieviruses A and B, echovirus

Fevers, murmurs, embolic phenomena, and the ultrasonographic findings suggest the diagnosis of _______________

bacterial endocarditis

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)

Formation of thrombi and emboli arising from these thrombi account for the common and the most serious complications following __________________

prosthetic valve implantation

What are clinical manifestations of right ventricular failure?

right atrial and ventricular dilation, hypertrophy, congestive hepatomegaly, congestive splenomegaly, peripheral edema, pleural effusion, ascites

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

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

Describe mitral valve prolapse and its primary form

one or both valves are enlarged

What is an adaptive response of the heart to systemic hypertensive heart disease?

hypertrophy

Calcific aortic valve stenosis causes _______________ to flow

obstruction

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

Name the bacterial agents in the low virulence HACEK group of oral cavity commensals associated with infective endocarditis?

Haemophilus, actinobacillus, cardiobacterium, eikenella, kingella

What are the most common causes of left sided heart failure?

Ischemic heart disease, systemic hypertension, mitral/aortic valve disease, primary diseases of the myocardium

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

What usually causes right sided heart failure?

Occurs due to left-sided heart failure, pressure increase in pulmonary circulation produces increased burden on right side

Describe Eisenmenger Syndrome

Prolonged left to right shunting with volume and pressure overloads eventually causes pulmonary hypertension and secondary right-sided pressures that exceed those of the left. At that point, reversal of blood flow occurs with resulting right to left shunting, and development of cyanosis. This reversal of flow and shunting of unoxygenated blood into the systemic circulation is Eisenmenger Syndrome.

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 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

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 arteriosus (STOPPED HERE 11/9)

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 (shortness of breath)

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

The central circulation contains blood that is in what?

heart, lungs (pulmonary blood vessels)

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 blood 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 closed, ventricles contract, ventricular muscle shortens, intraventricular pressure rises sharply ventricular ejection period: · AV valves closed, semilunar valves open, pressure in left and right ventricle exceed pressure in aorta and pulmonary artery, rapid ejection at first which slows 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

Describe the mechanism of cardiac cell contraction

· 1) An action potential, induced by the pacemaker cells in the SA and AV nodes, is conducted to contractile cardiomyocytes through gap junctions · 2) Action potentials travel between sarcomeres (smallest functional units of myofibril) activating Ca2+ channels in T-tubules, resulting in influx of Ca2+ ions into cardiomyocyte. · 3) Ca2+ ions in cytoplasm bind to troponin, troponin complex moves away from the actin-binding site, freeing up the actin to be bound by myosin and initiates contraction. · 4) Myosin head binds ATP and pulls actin filaments toward center of sarcomere, contracting muscle · 5) Intracellular Ca2+ is removed from sarcoplasmic reticulum, decreasing intracellular concentration, returning troponin complex to inhibitory state, effectively ending contraction as actin filaments return to initial position (muscle relax)

Define congestive heart failure and what it is caused by

· CHF occurs when the heart cannot generate sufficient output to meet the metabolic demands of the tissues. o CHF caused by many conditions that damage cardiac muscle such as: § Coronary artery disease § Heart attack § Cardiomyopathy § Other conditions that over work the heart (high blood pressure, valve disease, thyroid disease, kidney disease, diabetes, or heart defects present at birth)

What is the cardiac cycle?

· Cardiac cycle = rhythmic pumping of heart (0.8 seconds long) · Systole (ventricle contraction), diastole (ventricle relaxation)

Describe Tetralogy of Fallot

· Cardinal features: right ventricular outflow tract obstruction (pulmonary stenosis), right hypertrophy, ventricular septal defect (VSD), and overriding of VSD by the aorta · Consequences include right-to-left shunting, decreased pulmonary blood flow, and increased aortic volumes · Clinical severity largely depends on degree of pulmonary outflow obstruction

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 · Myocardial structural changes

Does compensated heart failure usually lead to decompensated heart failure?

· In compensated heart failure, the dilated ventricle can maintain cardiac output via the Frank-Starling mechanism · Ventricular dilation comes at expense of increased wall tension and amplifies O2 requirements of the myocardium · Eventually, the muscle fails and can't propel enough blood to meet needs of tissues and the patient develops decompensated heart failure

Describe the Frank-Starling mechanism

· Increased end-diastolic filling volumes dilate the heart and cause increased cardiac myofiber stretching, these lengthened fibers contract more forcibly, increasing cardiac output

Describe the 3 types of congenital atrial septal defects

· Ostium Secundum ASDs (90% of defects) occur when the growth of the septum secundum is insufficient to occlude the second ostium · Ostium Primum ASDs (5% of defects) occur at the lowest part of the atrial septum and can be associated with mitral and tricuspid valve abnormalities · Sinus Venosus ASDs (5% of defects) are located high in the atrial septum and often are accompanied by anomalous drainage of the pulmonary veins into the right atrium of superior vena cava

What is the SA node?

· Sinoatrial node (pacemaker of the heart), coordinates heart contraction · In upper wall of right atrium, generates nerve impulses that travel throughout the heart wall causing both atria to contract

Cardiac output

· The amount of blood pumped by the heart in liters/minute o Cardiac Output (CO) = Heart Rate (HR; bpm) x Stroke Volume (SV; amount pumped/beat)