Congestive Heart Failure Flashcards
What is heart failure?
inability of the heart to maintain its function of pumping blood to the lungs and the rest of the body
What medical conditions increase afterload?
On left side: HTN, aortic stenosis, aortic coarctation. On right side: pulmonary embolism
What is cardiac arrest/asystole?
cessation of normal circulation of the blood due to failure of the heart to contract effectively. brain injury is likely if longer than 5 minutes.
How does failure of the compensatory mechanism of the Frank-Starling Law of the heart explain the pathophysiology of heart failure?
the ventricle is loaded with blood to the point where heart muscle contraction becomes less efficient due to reduced ability to cross-link actin and myosin filaments in over-stretched heart muscle
What is reduced space capacity?
loss of cardiac reserve or the ability of the heart to work harder during physical activity since it can no longer meet normal O2 demands.
How does increased HR lead to left sided heart failure?
Initially, this helps compensate by maintaining BP. This places further strain on the myocardium, increasing coronary perfusion requirements, which can lead to worsening of ischemic heart disease
How does hypertrophy lead to left sided heart failure?
terminally differentiated heart muscle fibres increase in size to improve contractility. This contributes to the increased stiffness and decreased ability to relax during diastole
How does enlargement of the ventricle lead to left sided heart failure?
contributes to the spherical shape of the failing heart. The increase in ventricular volume also causes a reduction in stroke volume due to mechanical and contractile inefficiency.
What might you find on physical exam of right sided heart failure?
pitting peripheral edema, ascites, hepatomegaly, increased JVP, and parasternal heave
What is the jugular venous pressure?
Best estimate of right artrium pressure and right side function. Identify highest point of pulsation and measure from highest point vertically to the sternal angle. Abnormal if > 3 cm
What happens as a result of backward failure of left-side failure?
tachypnea, rales/crackles w/pulmonary edema (fluid in alveoli), cyanosis in severe pulmonary edema, orthopnea, paroxysmal nocturnal dyspnea, cardiac asthma
What is the most common mechanism of damage that leads to systolic dysfunction?
ischemia causing infarction and scar formation. After myocardial infarction, dead myocytes are replaced by scar tissue, deleteriously affecting the function of the myocardium
Describe the New York Heart Association Classification of heart failure
Class I: no limitation and no symptoms from ordinary activities. Class II: slight, mild limitation of activity and sx. Class III: marked limitation of any activity; the patient is comfortable only at rest. Class IV: symptoms occur at rest.
Describe the American College of Cardiology/American Heart Association classification of heart failure
Stage A: Patients at high risk for developing HF in the future. Stage B: a structural heart disorder but no symptoms at any stage. Stage C: previous or current symptoms of heart failure w/an underlying structural heart problem, managed with medical treatment. Stage D: advanced disease
What stage of heart failure are beta blockers contraindicated?
stage IV
