What are the signs and symptoms of left-sided heart failure?

Signs and Symptoms of Left-Sided Heart Failure

The primary signs and symptoms of left-sided heart failure include breathlessness (dyspnea), fatigue, pulmonary congestion, and peripheral edema, resulting from increased pulmonary capillary pressure and reduced cardiac output. 1

Respiratory Manifestations

• Dyspnea (shortness of breath), especially with exertion, is a cardinal symptom of left-sided heart failure 1, 2
• Paroxysmal nocturnal dyspnea (episodes of severe shortness of breath that wake patients from sleep) is characteristic of left-sided heart failure 1, 3
• Orthopnea (shortness of breath when lying flat) occurs due to increased venous return in the recumbent position 4, 5
• Pulmonary rales/crackles on auscultation due to fluid accumulation in the lungs 1, 2
• Cough, especially when lying down, due to pulmonary congestion 6, 7
• Cheyne-Stokes respiration (periodic breathing pattern) in severe cases 1

Cardiovascular Signs

• Pulmonary congestion resulting from elevated left atrial and pulmonary venous pressures 1, 2
• Tachycardia as a compensatory mechanism to maintain cardiac output 1, 2
• Third heart sound (S3 gallop) due to rapid ventricular filling in the setting of systolic dysfunction 7
• Cardiomegaly visible on chest radiography 1, 4
• Displaced cardiac apex on physical examination 7

Systemic Manifestations

• Fatigue and decreased exercise tolerance due to reduced cardiac output and skeletal muscle perfusion 1, 8
• Peripheral edema, particularly ankle swelling, resulting from fluid retention 1, 2
• Nocturia (frequent urination at night) due to improved renal perfusion when lying down 6
• Poor appetite and early satiety due to hepatic congestion and bowel edema 6
• Cachexia (muscle wasting) in advanced chronic heart failure 1

Diagnostic Findings

• Chest X-ray may show cardiomegaly, pulmonary congestion, interstitial or alveolar edema, and bilateral pleural effusions 1, 4
• Elevated B-type natriuretic peptide (BNP) or NT-proBNP levels support the diagnosis 1, 8
• Electrocardiogram may show evidence of left ventricular hypertrophy, prior myocardial infarction, or arrhythmias 4, 7
• Echocardiography provides objective evidence of cardiac dysfunction, which is required for diagnosis 4, 7

Important Clinical Considerations

• The severity of symptoms may not correlate with the degree of cardiac dysfunction - patients with preserved ejection fraction may have severe symptoms while those with reduced ejection fraction may be relatively asymptomatic 1, 4
• Symptoms alone are insufficient for diagnosis - objective evidence of cardiac dysfunction is required 1, 2
• Left-sided heart failure can be due to systolic dysfunction (reduced ejection fraction) or diastolic dysfunction (preserved ejection fraction) 2
• Acute decompensation may be precipitated by medication non-compliance, dietary indiscretion, acute coronary syndromes, arrhythmias, infections, or uncontrolled hypertension 1
• The New York Heart Association (NYHA) functional classification is commonly used to assess severity:
  • Class I: No limitation of physical activity 6
  • Class II: Slight limitation (symptoms with ordinary exertion) 6
  • Class III: Marked limitation (symptoms with less-than-ordinary exertion) 6
  • Class IV: Unable to perform any physical activity without discomfort 6

Pathophysiological Basis

• Left ventricular dysfunction leads to increased left ventricular filling pressures 1, 8
• Elevated left atrial pressure causes pulmonary venous congestion 1, 2
• Increased pulmonary capillary pressure contributes to pulmonary edema and breathlessness 4, 3
• Low cardiac output leads to fatigue, peripheral hypoperfusion, and activation of neurohormonal systems 4, 8
• Cardiac remodeling with chamber dilation and/or hypertrophy occurs as the disease progresses 1, 8