Pulmonary Heart Disease (Cor Pulmonale)

Introduction
Essentials of Diagnosis

  • Symptoms and signs of chronic bronchitis and pulmonary emphysema.
  • Elevated jugular venous pressure, parasternal lift, edema, hepatomegaly, ascites.
  • ECG shows tall, peaked P waves (P pulmonale), right axis deviation, and right ventricular hypertrophy.
  • Chest x-ray: Enlarged right ventricle and pulmonary artery.
  • Echocardiogram or radionuclide angiography excludes primary left ventricular dysfunction.

General Considerations
The term “cor pulmonale” denotes right ventricular hypertrophy and eventual failure resulting from pulmonary disease and attendant hypoxia or from pulmonary vascular disease. Its clinical features depend upon both the primary underlying disease and its effects on the heart.

Cor pulmonale is most commonly caused by COPD. Less frequent causes include pneumoconiosis, pulmonary fibrosis, kyphoscoliosis, primary pulmonary hypertension, repeated episodes of subclinical or clinical pulmonary embolization, Pickwickian syndrome, schistosomiasis, and obliterative pulmonary capillary or lymphangitic infiltration from metastatic carcinoma.

Clinical Findings

A. Symptoms and Signs
The predominant symptoms of compensated cor pulmonale are related to the pulmonary disorder and include chronic productive cough, exertional dyspnea, wheezing respirations, easy fatigability, and weakness. When the pulmonary disease causes right ventricular failure, these symptoms may be intensified. Dependent edema and right upper quadrant pain may also appear. The signs of cor pulmonale include cyanosis, clubbing, distended neck veins, right ventricular heave or gallop (or both), prominent lower sternal or epigastric pulsations, an enlarged and tender liver, and dependent edema.

B. Laboratory Findings
Polycythemia is often present in cor pulmonale secondary to COPD. The arterial oxygen saturation is often below 85%; PCO2 may or may not be elevated.

C. Electrocardiography and Chest X-Ray
The ECG may show right axis deviation and peaked P waves. Deep S waves are present in lead V6. Right axis deviation and low voltage may be noted in patients with pulmonary emphysema. Frank right ventricular hypertrophy is uncommon except in primary pulmonary hypertension. The ECG often mimics myocardial infarction; Q waves may be present in leads II, III, and aVF because of the vertically placed heart, but they are rarely deep or wide, as in inferior myocardial infarction. Supraventricular arrhythmias are frequent and nonspecific.

The chest radiograph discloses the presence or absence of parenchymal disease and a prominent or enlarged right ventricle and pulmonary artery.

D. Diagnostic Studies
Pulmonary function tests usually confirm the underlying lung disease. The echocardiogram should show normal left ventricular size and function but right ventricular dilation. Perfusion lung scans are rarely of value, but, if negative, they help to exclude pulmonary emboli, an occasional cause of cor pulmonale. Pulmonary angiography is the most specific method of diagnosis for the pulmonary emboli, but it carries increased risk when performed in patients with pulmonary hypertension.

Differential Diagnosis
In its early stages, cor pulmonale can be diagnosed on the basis of radiologic, echocardiographic, or electrocardiographic evidence. Catheterization of the right heart will establish a definitive diagnosis but is usually performed to exclude left-sided heart failure, which may in some patients be an inapparent cause of right-sided failure. Differential diagnostic considerations relate chiefly to the specific pulmonary disease that has produced right ventricular failure (see above).

Treatment
The details of the treatment of chronic pulmonary disease (chronic respiratory failure) are discussed in Pulmonary Diseases section. Otherwise, therapy is directed at the pulmonary process responsible for right heart failure. Oxygen, salt and fluid restriction, and diuretics are mainstays; digitalis has no place in right heart failure unless atrial fibrillation is present.

Prognosis
Compensated cor pulmonale has the same prognosis as the underlying pulmonary disease. Once congestive signs appear, the average life expectancy is 2-5 years, but survival is significantly longer when uncomplicated emphysema is the cause.

Budev MM et al: Diagnosis and evaluation of pulmonary hypertension. Cleve Clin J Med 2003;70(Suppl 1):S9.

Lehrman S et al: Primary pulmonary hypertension and cor pulmonale. Cardiol Rev 2002;10:265.

Vizza CD et al: Right and left ventricular dysfunction in patients with severe pulmonary disease. Chest 1998;113:576.

Provided by ArmMed Media
Revision date: July 7, 2011
Last revised: by David A. Scott, M.D.