ESSENTIALS OF DIAGNOSIS
Associated with chronic bronchitis or emphysema or pulmonary hypertension.
Elevated jugular venous pressure, parasternal lift, edema, hepatomegaly, ascites.
ECG shows tall, peaked P waves (P pulmonale), right axis deviation, and RVH.
Echocardiogram excludes primary LV dysfunction.
The term “cor pulmonale” denotes RV systolic and diastolic failure resulting from pulmonary disease and the attendant hypoxia or from pulmonary vascular disease (pulmonary hypertension). Its clinical features depend on both the primary underlying disease and its effects on the heart.
Cor pulmonale is most commonly caused by pulmonary hypertension from any cause, COPD or idiopathic pulmonary fibrosis. Less frequent causes include pneumoconiosis and kyphoscoliosis.
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 RV failure, these symptoms may be intensified. Dependent edema and right upper quadrant pain may also appear. The signs of cor pulmonale include cyanosis, clubbing (see Figure 6–41), distended neck veins and tricuspid regurgitation, an RV heave or gallop (AUDIO 10–24) (or both), prominent lower sternal or epigastric pulsations, an enlarged and tender liver, dependent edema, and ascites. Severe lung disease can be a cause of low cardiac output by reducing LV filling and subsequently LV preload and stroke volume.
Audio 10–24. A summation gallop in heart failure.
(Reproduced, with permission, from T. Anthony Don Michael, MD. Mastering Auscultation [CD-ROM], 2000.)
RV volume and function differ depending on the degree of emphysema present in patients with COPD; those with greater degrees of emphysema have smaller RV volumes and mass and a lower RVEF as assessed by cardiac MRI than those with less emphysema.
Polycythemia is often present in cor pulmonale secondary to chronic hypoxemia. The arterial oxygen saturation is often below 85% and frequently falls with exertion; PCO2 may or may not be elevated. Cyanosis is more prevalent if there is right to left shunting via a PFO.
C. ECG and Chest Radiography
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 RVH is uncommon except when pulmonary hypertension is associated. The ECG often mimics MI; 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 MI (see eFigure 10–17). Supraventricular arrhythmias are frequent and nonspecific.
The chest radiograph discloses the presence or absence of parenchymal disease and a ...