Cor Pulmonale/Right Heart Failure

KEY FEATURES

ESSENTIALS OF DIAGNOSIS

• Respiratory or pulmonary vascular disease

• Elevated jugular venous pressure, hepatomegaly, peripheral edema

• Normal or near-normal left ventricular (LV) function and filling pressures

GENERAL CONSIDERATIONS

• Alteration in the structure and function of the right ventricle (RV) caused by pulmonary hypertension (PH)

• Pathophysiology: pulmonary vasoconstriction due to alveolar hypoxia or blood acidemia; reduced cross-sectional area of the pulmonary vascular bed

• Causes:

  • – Lung disorders (eg, emphysema, pulmonary fibrosis)

  • – Acute or chronic pulmonary embolism

  • – Increased blood viscosity (eg, polycythemia vera, sickle cell disease, macroglobulinemia)

  • – Pulmonary arterial hypertension

• Acute right heart failure may accompany acute respiratory failure or pulmonary embolism

• RV hypertrophy predominates in chronic pulmonary hypertensive states

• RV dilatation and dysfunction predominantly occur with acute cor pulmonale

• Acute cor pulmonale is usually due to acute pulmonary thromboembolism

CLINICAL PRESENTATION

SYMPTOMS AND SIGNS

• Symptoms may be vague and subtle, especially in the early stages

• Fatigue, exercise intolerance

• Dyspnea

• Syncope

• Chest discomfort (usually exertional)

• Palpitations

• Dizziness

• Cough

• Hemoptysis

PHYSICAL EXAM FINDINGS

• Tachypnea

• Tachycardia

• Systemic hypotension

• Elevated jugular venous pressure

• Labored respiratory efforts with retractions of the chest wall

• Hyperresonance to lung percussion

• Diminished breath sounds

• Pulmonary wheezes

• Left parasternal lift

• Distant heart sounds

• Accentuated pulmonic component of the S₂

• Split second heart sound that increases with inspiration

• Holosystolic murmur at the lower sternal border (tricuspid regurgitation)

• Diastolic murmur along the left sternal border due to pulmonary regurgitation may be present

• Right-sided S₃ and S₄

• Hepatomegaly; pulsatile liver (with severe tricuspid regurgitation)

• Abdominal fluid wave from ascites

• Peripheral edema

• Cyanosis

DIFFERENTIAL DIAGNOSIS

• Right heart failure due to left heart failure

• RV myocardial infarction

• Constrictive pericarditis

• Other cardiac causes of right heart failure, such as pulmonic stenosis or atrial septal defect

DIAGNOSTIC EVALUATION

LABORATORY TESTS

• CBC (polycythemia may be present)

• Serum electrolytes (including calcium, magnesium),

• Blood urea nitrogen and creatinine

• Serum uric acid level (may be elevated from diuretics)

• Liver function tests (elevated with hepatic congestion)

• Coagulation studies

• Antinuclear antibody and rheumatoid factor, hypercoagulability laboratories, HIV test, thyroid function test, serum alpha₁-antitrypsin (if deficiency is suspected) to exclude causes of PH

ELECTROCARDIOGRAPHY

• Sinus tachycardia

• Atrial fibrillation or flutter

• Premature atrial contractions

• Multifocal atrial tachycardia

• Junctional tachycardia

• Low-voltage QRS in patients with chronic obstructive pulmonary disease (COPD)

• Right atrial enlargement (P pulmonale)

• Right bundle branch block

• RV hypertrophy: R/S amplitude ratio > 1 mV in lead V1 and right-axis deviation (QRS axis of +110°)

IMAGING STUDIES

• Chest x-ray findings vary with underlying disorder

• Transthoracic echocardiography: RV hypertrophy may be present

  • – RV dilatation with reduced systolic function

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