Heart Failure Flashcards
Pathologic changes that lead to heart failure
increased fluid volume/FVO, impaired ventricular filling, decreased ventricular contractile function
Etiology of heart failure
Ischemic heart disease, chronic hypertension, chronic pulmonary disease, cardiomyopathies, dysrhythmias, heart valve abnormalities
How does ischemic heart disease cause heart failure
lack of sufficient coronary circulation causes repeated ischemia or infarction to the myocardium, decreasing the contractions of the ventricles
How does chronic hypertension cause heart failure
LVH occurs predisposing the left ventricle to ischemic injury and inadequate perfusion, enlarging the cardiac muscle, more workload and weakened ventricles
How does restrictive cardiomyopathy cause heart failure
the ventricle is impaired from filling to full capactiy
How does ischemic cardiomyopathy cause heart failure
fibrous and scarring of the heart muscle cause by coronary insufficiency and MI
How does hypertrophic cardiomyopathy cause heart failure
the left ventricle is enlarged and the hypertrophy causes stiffness and obstruction of blood during systole cause by genetic predisposition
How do tachydysrhythmias cause heart failure
reduce the time available for ventricular filling
How do bradydysrhythmias cause heart failure
slow the heart rate enough to minimize CO
How do atrial dysrhythmias cause heart failure
diminish the volume emptied into the ventricle, decreasing SV and CO
How does mitral regurgitation cause heart failure
the mitral valve does not close completely during systole –> back-up of fluid into the atrium –> backward pressure in the pulmonary veins –> increased pulmonary capillary hydrostatic pressure
–> fluid leakage into the pulmonary interstitium
How does aortic stenosis cause heart failure
calcification of the aortic valve with aging, narrowing the valve and impedes ejection of blood flow from the left ventricle causing LVH
How do endocarditis and myocarditis cause heart failure
infection causes biochemical and structural changes to the heart. Leads to deterioration of contractile strength of ventricular muscle
How does a pulmonary embolism cause heart failure
raises pressure creating a backwards resistance into the right ventricle, weakening the muscle causing RVF
Acute heart failure
occurs from a massive MI that causes ventricular injury leading to cardiogenic shock from the inability to maintain blood pressure and perfusion to the body
Systolic dysfunction
the weakened ventricle has difficulty ejecting blood out of the chamber, or poor forward pumping action which causes reduced SV/CO
Diastolic dysfunction
the ventricle has difficulty relaxing and cannot fill, pumping out insufficient volume of blood for the body
High-output failure
the heart cannot pump blood to the tissues
Low-output failure
not enough blood returns to the heart
Diagnostic criteria for heart failure
need one major and two minor criteria, observe clinical manifestations, history, and lab finding
Major s/s of heart failure
PND, JVD, pulmonary crackles, cardiomegaly, S3 sound, increased CVP, hepatojuglar reflux
Minor s/s of heart failure
bilateral edema, DOE, hepatomegaly, pleural effusion, tachycardia, reduced pulmonary capacity
What lab and diagnostic studies are done
BNP levels, serum electrolyte levels, chest x-ray, ECG, echocardiogram
BNP
increased secretion due to stretching of the ventricle with increased fluid volume, >500 is indicative of heart failure
Serum electrolytes
excess fluid volume causes hyponatremia/kalemia, constant cycling of RAAS chaanges potassium excreting from kidneys, hypokalemia increases dysrhythmia risk
Chest x-ray
shows cardiac shadow, cardiomegaly, vascular congestion, kerley A/B lines
What do kerley A/B lines indicate
engorged blood vessels of the lungs –> left sided HF
ECG
demonstrated various abnormalities
Echocardiogram
shows activity and structures of the heart
Treatment of heart failure
diuretics, synthetic natriuretics, vasodilators, ACE inhibitors, beta-adrenergic blockers, inotropic agents, LVAD, intra-aortic assist device, cardiac resynchronization therapy
Diuretics
enhance water loss
Synthetic natriuretics
synthetic form of BNP that acts to increase diuresis at renal vasculature
Vasodilators
nitrates are both arterial and venous vasodilators that enhance coronary circulation and decrease the heart’s workload
ACE inhibitors
inhibit vasoconstriction and stimulation of aldosterone, decreases resistance against LV, lower blood volume and and ease workload of the heart
Beta-adrenergic blockers
inhibit effects of SNS, reduces strain on heart
Inotropic agents
increase the contractile force of the heart muscle
Digitalis
inotropic agent that increases the force and rate of the heart, slowing conduction through AV node, measure apical pulse for 1 minute, monitor potassium
Intra-aortic balloon assist device
increase aortic pressure and blood flow
CRT
specialized pace maker to optimize pumping by coordinating impulse
