Congestive Heart Failure: Reduced Ejection Fraction

KEY FEATURES

ESSENTIALS OF DIAGNOSIS

• Dyspnea on exertion, paroxysmal nocturnal dyspnea, orthopnea, and dyspnea at rest (late stage)

• Jugular venous distention, peripheral edema, sinus tachycardia, pulmonary rales, cardiomegaly, S₃, and liver enlargement

• Left ventricular (LV) systolic dysfunction

GENERAL CONSIDERATIONS

• Lifetime risk of developing heart failure is 20% for Americans ≥ 40 years old

• Approximately 600,000 new patients each year

• Complex clinical syndrome characterized by dysfunction of the left, right, or both ventricles and changes in neurohumoral regulation

• Effort intolerance, fluid retention, and shortened survival

• Principal clinical manifestations result from inadequate forward cardiac output

• Neurohumoral activation responsible for fluid retention, peripheral edema, and an increase in peripheral resistance

• Manifestations depend on the rate of heart failure development with adaptive mechanisms minimizing symptoms and chronic heart failure

• Causes:

  • – Coronary artery disease

  • – Idiopathic/familial dilated cardiomyopathy

  • – Metabolic causes (alcohol, nutritional and thyroid disorders, pheochromocytoma)

  • – Drugs and toxins

  • – Myocarditis

  • – Connective tissue diseases

  • – Chemotherapy-induced

  • – Inherited storage diseases

  • – Infiltrative diseases

CLINICAL PRESENTATION

SYMPTOMS AND SIGNS

• Dyspnea

• Paroxysmal nocturnal dyspnea

• Orthopnea

• Cough

• Fatigue and weakness

• Nocturia and oliguria

• Abdominal bloating and discomfort

PHYSICAL EXAM FINDINGS

• Tachycardia

• Hypotension

• Tachypnea

• Diaphoresis

• Elevated jugular venous pressure

• Pulmonary rales

• Reduced breath sounds and dullness to percussion consistent with pleural effusions

• Laterally displaced, enlarged, and sustained ventricular impulse

• Murmurs of tricuspid and mitral regurgitation

• S₃ and sometimes S₄

• Hepatomegaly, pulsatile liver with tricuspid regurgitation

• Abdominal fluid wave due to ascites

• Peripheral edema

• Pulses alternans

• Reduced pulse pressure

• Cool, clammy skin

DIFFERENTIAL DIAGNOSIS

• Chronic lung disease, chronic bronchitis

• Pneumonia

• Pulmonary emboli

• Pericardial disease—tamponade or constriction

• Nephrosis

• Hepatic cirrhosis

• Hypothyroidism

DIAGNOSTIC EVALUATION

LABORATORY TESTS

• CBC: to exclude anemia or infection

• Serum electrolytes (including calcium and magnesium), blood urea nitrogen, creatinine, glucose

• Urinalysis

• Liver function tests

• Fasting lipid profile

• Thyroid function tests

• Measurement of B-type natriuretic peptide (BNP) or N-terminal pro-BNP (NT-proBNP) may be useful

• Measurement of cardiac troponin

ELECTROCARDIOGRAPHY

• Sinus tachycardia

• Atrial fibrillation

• Ventricular premature beats

• Intraventricular conduction delay

• Nonspecific ST- and T-wave segment changes

IMAGING STUDIES

• Chest x-ray findings:

  • – Cardiomegaly

  • – Interstitial and perivascular edema

  • – Kerley B lines

  • – Pleural effusions

• Typical transthoracic echocardiography findings:

  • – Biatrial enlargement

  • – Left and/or right ventricular wall motion abnormalities, hypertrophy, enlargement, and/or reduced contractility

  • – Diastolic dysfunction due to elevated cardiac filling pressures

  • – Eccentric hypertrophy

  • – Functional mitral and tricuspid regurgitation

• Noninvasive imaging to detect myocardial ischemia and myocardial viability is reasonable for patients with known coronary artery disease unless the patient is not eligible for revascularization

• Cardiac MRI is reasonable when ...