Flashcards in Card - Path (Part 4: Cardiomyopathies & CHF) Deck (31):
What is the most common cardiomyopathy? For what percentage of cases does it account?
Dilated cardiomyopathy; Most common cardiomyopathy (90% of cases)
What 2 general causes of dilated cardiomyopathy that often occur? What are 8 other, more specific etiologies?
Often idiopathic or congenital; Other etiologies include Alcohol abuse, wet Beriberi, Coxsackie B virus myocarditis, chronic Cocaine use, Chagas disease, Doxorubicin toxicity, hemochromatosis, and peripartum cardiomyopathy; Think: "ABCCCD"
What are 4 clinical findings associated with dilated cardiomyopathy?
Findings: (1) heart failure (2) S3 (3) dilated heart on echocardiogram (4) balloon appearance of heart on CXR
What are 7 treatments for dilated cardiomyopathy?
Treatment: (1) Na+ restriction, (2) ACE inhibitors, (3) Beta-blockers, (4) Diuretics, (5) Digoxin, (6) Implantable cardioverter defibrillator (ICD), (7) Heart transplant
What kind of cardiac dysfunction results from dilated cardiomyopathy?
Systolic dysfunction ensues
What kind of hypertrophy occurs with dilated cardiomyopathy, and why?
Eccentric hypertrophy (sarcomeres added in series)
What percentage of hypertrophic cardiomyopathy cases are familial, autosomal dominant? What is commonly the mutation?
60-70% of cases are familial, autosomal dominant (commonly a Beta-myosin heavy-chain mutation).
With what condition can hypertrophic cardiomyopathy rarely be associated?
Rarely can be associated with Friedreich ataxia
With what patient population is hypertrophic cardiomyopathy associated, and in what context?
Cause of sudden death in young athletes, due to ventricular arrhythmia
What are 2 clinical findings associated with Hypertrophic cardiomyopathy?
Findings: (1) S4 (2) Systolic murmur
What is the treatment for hypertrophic cardiomyopathy? What is the treatment for particularly high risk patients?
Treatment: Cessation of high-intensity athletics, use of Beta-blocker or non-dihyropyridine calcium channel blocks (e.g., verapamil). ICD if patient is high risk.
What kind of cardiac dysfunction occurs with hypertrophic cardiomyopathy?
Diastolic dysfunction ensues.
What are the gross and histologic findings that characterize cardiac hypertrophy?
Marked (concentric) ventricular hypertrophy, often septal predominance. Myofibrillar disarray and fibrosis
What pathophysiology and outcome(s) characterize the obstructive HCM subset?
Obstructive HCM (subset): Hypertrophied septum too close to anterior mitral leaflet => outflow obstruction => dyspnea, possible syncope
What are 6 major causes of Restrictive/infiltrative cardiomyopathy?
Major causes include (1) sarcoidosis, (2) amyloidosis, (3) postradiation fibrosis, (4) endocardial fibroelastosis (thick fibroelastic tissue in endocardium of young children), (5) Loffler syndrome (endomyocardial fibrosis with a prominent eosinophilic infiltrate), and hemochromatosis (dilated cardiomyopathy can also occur)
What characterizes endocardial fibroelastosis? With what kind of cardiomyopathy is it associated?
Endocardial fibroelastosis (thick fibroelastic tissue in endocardium of young children); Restrictive cardiomyopathy
What characterizes Loffler syndrome? With what kind of cardiomyopathy is it associated?
Loffler syndrome (endomyocardial fibrosis with a prominent eosinophilic infiltrate); Restrictive cardiomyopathy
With what cardiomyopathies is hemochromatosis associated?
Restrictive/infiltrative; Hemochromatosis (dilated cardiomyopathy can also occur)
What kind of cardiac dysfunction occurs in restrictive/infiltrative cardiomyopathy?
Diastolic dysfunction ensues
What ECG finding characterizes restrictive/infiltrative cardiomyopathy? For what cause of restrictive/infiltrative cardiomyopathy is this especially the case?
Can have low-voltage ECG despite thick myocardium (especially amyloid)
What is CHF?
Clinical syndrome of cardiac pump dysfunction
What are 3 symptoms and 3 signs that characterize CHF?
Symptoms include dyspnea, orthopnea, and fatigue; Signs include rales, JVD, and pitting edema
What occurs as a result of systolic versus diastolic dysfunction in CHF?
Systolic dysfunction - low EF, poor contractility, often secondary to ischemic heart disease or DCM; Diastolic dysfunction - normal EF and contractility, impaired relaxation, decreased compliance
To what is systolic dysfunction in CHF often secondary?
Often secondary to ischemic heart disease or DCM
From what does right heart failure most often result? Other than this, what usually causes right heart failure, and in what context?
Right heart failure most often results from left heart failure. Isolated heart failure is usually due to cor pulmonale.
What are 4 drugs that that decrease mortality in CHF? What 2 drugs are used in CHF mainly for symptomatic relief? What drug therapy improves both symptoms and mortality in select patients?
ACE inhibitors, Beta-blockers (except in acute decompensated HF), angiotensin II receptor blockers, and spironolactone decrease mortality. Thiazide or loop diuretics are used mainly for symptomatic relief. Hydralazine with nitrate therapy improves both symptoms and mortality in select patients.
What are 2 general abnormalities of CHF (i.e., not directly related to left or right heart failure)? What causes each?
(1) Cardiac dilation - Greater ventricular end-diastolic volume (2) Dyspnea on exertion - Failure of CO to increase during exercise
What are 3 abnormalities of CHF associated with left heart failure? What defines and/or causes each?
(1) Pulmonary edema - increased pulmonary venous pressure => pulmonary venous distention and transudation of fluid. Presence of hemosiderin-laiden macrophages ("heart failure" cells) in lungs. (2) Orthopnea - Shortness of breath when supine: Increased venous return from redistribution of blood (immediate gravity effect) exacerbates pulmonary vascular congestion. (3) Paroxysmal nocturnal dyspnea - breathless awakening from sleep: Increased venous return from redistribution of blood, reabsorption of edema, etc.
What is a key histologic effect in the lungs during CHF, and what causes this?
Pulmonary edema - increased pulmonary venous pressure => pulmonary venous distention and transudation of fluid. Presence of hemosiderin-laiden macrophages ("heart failure" cells) in lungs.
What are 3 abnormalities of CHF associated with right heart failure? What causes each?
(1) Hepatomegaly (nutmeg liver) - Increased central venous pressure => Increased resistance to portal flow. Rarely, leads to "cardiac cirrhosis". (2) Peripheral edema - Increased venous pressure => Fluid transudation (3) Jugular venous distention - Increased venous pressure