Pharmacotherapy of Heart Failure Flashcards
Definition of heart failure
heart is unable to pump blood in quantities sufficient to support the body’s oxygenation needs
Types of heart failure
Systolic- dysfunction in LV contractility
Diastolic- LV stiffness and delayed filling
Signs of heart failure
left sided CHF: pulmonary congestion
right sided CHF: limb edema, ascites, weight gain
cardiac enlargement, myocardial ischemia, tachycardia, atrial fib\
Classes of Heart Failure
Class I: cardiac lesion, patient shows no signs
Class II: signs of CHF during exercise
Class III: signs of CHF normally
Class IV: signs of CHF at rest
Treatment for Class I CHF
exercise restrictions, decreased Na+ intake
Treatment for Class II CHF
exercise restrictions, decreased Na+ intake, thiazide diuretics and spironolactone
Treatment for Class III CHF
exercise restrictions, decreased Na+ intake, thiazide diuretics and spironolactone, positive inotropes (digitalis) OR vasodialators OR beta-AR blockers (carvedilol)
Treatment for Class IV CHF
exercise restrictions, decreased Na+ intake, thiazide diuretics and spironolactone, positive inotropes (digitalis) AND vasodialators OR beta-AR blockers (carvedilol)
Goal of diuretics
decrease blood volume (preload) by increasing Na excretion and decreasing blood volume
Goal of vasodilators
decreasing outflow resistance and venous return
decrease blood pressure, increase tissues perfusion, increase Na and H2O excretion
Diuretic treatment in CHF: which ones?
loop more effective, but lose lots of K+
thiazide are less effective, useful in mild CHF and can be used in combo with loop
aldosterone antagonists like spironolactone can be used with thiazide and loop, may increase survival time
Examples of drugs used as vasodilators in CHF
ACE inhibitors like enalapril, Ca++ blockers like amlodipine
Examples of drugs used as vasodilators in AHF (acute heart failure)
sodium nitroprusside
How can the renin-angiotensin system be regulated to benefit CHF patients?
inhibit renin activity, inhibit angiotensin-convering enzyme and decrease angiotensin II production (enalapril), block angiotensin II receptors, reduce effects of aldosterone (spironolactone)
What is the effect of treating with NSAIDs and ACE inhibitors?
GFR is compromised because of the downregulation of PGE and PGI (vasodilator of afferent arteriole) and the downregulation of angiotensin (vasocontriction of efferent venules)