Heart Failure

Sangjin Lee

Robert E. Hobbs

POINTS TO REMEMBER

The most common cause of heart failure in the United States is end-stage coronary artery disease, accounting for more than half of cases.
Systolic heart failure refers to contractile impairment manifested by low left ventricular ejection fraction (LVEF).
Diastolic heart failure, also called heart failure with preserved ejection fraction occurs in the setting of preserved LVEF and is associated with abnormal left ventricular relaxation and filling, left ventricular hypertrophy, and elevated intracardiac pressures.
- Diastolic dysfunction occurs with hypertensive heart disease, ischemic heart disease, hypertrophic cardiomyopathy, restrictive cardiomyopathy (including infiltrative diseases), and aortic valve disease.
High-output heart failure is rare. The causes of high-output heart failure include thyrotoxicosis, arteriovenous fistula, pregnancy, Paget’s disease, anemia, and beriberi.
Jugular venous distension is the most important and sensitive physical exam finding in patients with decompensated failure, indicating fluid overload.
The degree of functional impairment usually is stated in terms of the New York Heart Association classification:
- Class I refers to no limitation of physical activity and no dyspnea or fatigue with ordinary physical activities.
- Class II indicates mild limitation of physical activity and dyspnea or fatigue occurring with ordinary physical activities. The patient has no symptoms at rest.
- Class III implies marked limitation of activity. Less than ordinary physical activities cause symptoms. The patient is asymptomatic at rest.
- Class IV refers to symptoms at rest and with any physical exertion.
The B-type natriuretic peptide (BNP) assay is a useful test for determining whether dyspnea is due to heart failure. Elevated levels of BNP in general correlate with the severity and prognosis of heart failure. BNP levels are not as reliable in the setting of chronic kidney disease.
Echocardiography is the single most useful diagnostic test in heart failure.
Many therapies for heart failure attempt to modulate neurohormonal factors. Sympathetic nervous system excess may be modulated through the use of β-blockers and possibly digoxin. The renin-angiotensin system may be inhibited by angiotensin-converting enzyme inhibitors, angiotensin II receptor blockers, and aldosterone receptor antagonists.
Current indications for implantable cardiac defibrillator placement include survivors of a cardiac arrest, sustained ventricular tachycardia, unexplained syncope with inducible ventricular tachycardia, and dilated or ischemic cardiomyopathy with ejection fraction ≤35%.