Heart Failure Flashcards
Symptoms of L-sided HF
dyspnea, fatigue, edema, and specifically for L: PULMONARY CONGESTION
Most common causes of L-sided HF
general: MI, atherosclerotic heart ds, hypertensive changes, valve ds, dilated cardiomyopathy, congenital heart ds. Most common: MYOCARDIAL ISCHEMIA due to coronary artery ds, followed by HTN
Symptoms of R-sided HF
dyspnea, fatigue, edema, and specifically for R: PERIPHERAL EDEMA
Most common causes of R-sided HF
general: MI, atherosclerotic heart ds, hypertensive changes, valve ds, dilated cardiomyopathy, congenital heart ds. Most common: MYOCARDIAL ISCHEMIA due to coronary artery ds, followed by HTN
Compensatory effects of HF
3 major responses: Increase sympathetic activity, activate RAS (renin-angiotensin system), myocardial hypertrophy
Two Pathways of SNS stimulation during HF
Stimulation of B-adrenergic receptors; alpha 1-adrenergic stimulation
Effects of alpha 1-adrenergic stimulation in HF
produces vasoconstriction that enhances venous return, Increase cardiac preload and afterload.
Effects of B-adrenergic stimulation in HF
Stimulation of B-adrenergic receptors in heart Increase HR, Increase force of contraction
Adverse Effects of SNS Stimulation as a Compensatory Measure in HF
Increase work-load of heart (which causes further decline in cardiac function)
Mechanism of Renin-Angiotensin System Activation due to HF
Decrease in CO leads to Decrease renal blood flow that triggers release of renin to both: Increase formation of angiotensin II (vasoconstrictor that Increase peripheral resistance); and release aldosterone
Effects of Renin-Angiotensin System Activation in HF
Release of aldosterone promotes retention of Na & water thus Increase blood vol and amount of blood returned to heart
Adverse Effects of Renin-Angiotensin System Activation in HF
edema because of Increase venous pressure due to inability of heart to pump extra vol
Effects of Myocardial Hypertrophy in HF
Myocardial Hypertrophy: heart Increase size via: chambers dilate; initial stretching leads to more forceful, stronger contraction, but excessive elongation of fibers and thus weaker contractions (ultimately Decrease ejection ability - systolic failure); a
Compensated HF
compensatory mechanisms (myocardial hypertrophy, RAS activation, SNS stimulation0 are restoring ADEQUATE CARDIAC OUTPUT
Decompensated HF
mechanisms eventually Increase overall workload on heart and lead to furhter decline in cardiac functio; compensatory mechanisms FAIL TO MAINTAIN ADEQUATE CO
Drug classes used to treat HF
Inhibitors of renin-angiotensin-aldosterone system (RAAS); β-blockers; diuretics; inotropic agents; direct vasodilators; aldosterone antagonists
Types of RAAS Inhibitors
ACE inhibitors; Angiotensin-Receptor Blockers (ARBs)
Indications for ACEIs
MONOTHERAPY (pts with mild DOE and no apparent signs of vol overload); ASYMPTOMATIC PTS WITH EJECTION FRACTION <35% (left ventricular dysfunction); PTS WITH RECENT MI; all stages LEFT VENTRICULAR FAILURE with or w/o symptoms
Indications for ARBs
Angiotensis-Receptor Blockers (ARBs): HTN, SUBSTITUTES FOR ACEI (esp. when ACEI associated with cough &/or angioedema)
Indications for B-Blockers
Unless BB therapy contraindicated, BB should be used in management of HF
Indications for Loop Diuretics
provide relief of volume overload symptoms (dyspnea and peripheral edema)
Primary Inotropic Drug
Digoxin
Indications for Direct Vasodilators
Add on therapy
Aldosterone Antagonists
Spironolactone; eplerenone
Indications for Aldosterone Antagonists
aldosterone antagonists: spironolactone: reserved for most severe HF cases; eplerenone: REDUCES MORTALITY in L VT SYSTOLIC DYSFUNCTION, HF AFTER ACUTE MI
Which B-blockers are indicated for HF
CARVEDILOL (COREG) - non-selective B-blockade, also alpha -blockade. METOPROLOL (LOPRESSOR); Long-Acting variant (Toprol)- B1 selective (cardioselective), immediate or extended release
When B-blockers are indicated for HF
used for structural heart ds, no symptoms in selected pts with ACEI; structural heart ds with previous or current symptoms in all pts with ACEI
3 Stages of HF
Stage A: High Risk, No Symptoms Stage B: Structure HD, No Symptoms Stage C: Structure HD, previous or current symptoms
Treatment Regimen for Stage A HF (Lowest Level)
Risk-factor reduction; patient education
Treatment Regimen for Stage A (2nd tier) HF
Treat HTN, DM, dyslipidemia; ACEIs or ARBs in SOME patients
Treatment Regimen for Stage B HF
ACEIs or ARBs in ALL patients; B-blocker in selected patients
Treatment Regimen for Stage C HF
ACEIs and B-Blockers in ALL patients
Treatment Regimen for Stage C HF (Highest Level)
ACEIs and B-Blockers in ALL patients; dietary Na+ restriction; diuretics & digoxin
Use of digoxin
- increase cardiac contractility
- improve ejection fraction
- lower diastolic volume,
- improved circulation
MoA of digoxin
promotes calcium entry into the cell and causees retention of calcium in the cell
Indication for digoxin
in severe left ventricular systolic dysfunction - after initiation of a ACE inhibitor and diuretic
Half-life of digoxin
36 hours (very long)
Side effects of digoxin
GI effects: anorexia (due to N/V), N/V; CNS effects: headache, fatigue, confusion, blurred vision, alteration of color perception and halos
Use of spironolactone
direct antagonist of aldosterone
MoA of spironolactone
prevents salt retention, myocardial hypertrophy and hypokalemia due to elevated aldosterone levels and angiotensin II stimulation and reduced hepatic clearence
Indication for for spironolactone
Reserved for the most severe heart failure cases
Half-life of spironolactone (active metabolites)
14-22 hr
Side effects of spironolactone
GI disturbances, lethargy and confusion, gynecomastia;progestational and antiandrogenic adverse effects due to its nonspecific binding to various steroid receptors
Use of eplerone
competitive antagonist of aldosterone
MoA of eplerone
lower incidence of endocrine related side effects because of reduced affinity for glucocorticoid, andogen and progesterone receptors
Indications for eplerone
left ventricular systolic dysfunction and heart failure after acute myocardial infarction
Half-life of eplerone
4-6 hr
Side effects of eplerone
Reduced compared to spironolactone
Treatment for overt HF
loop diuretics are initated first to provide relief of volume overload; then an ACE inhibitor or ARB is induced; third, beta blockers are started after the patient is stable on ACE and finally digoxin is added if needed (symptoms remain)
