COR PULMONALE

RV enlargement resulting from primary lung disease; leads to RV hypertrophy and eventually to RV failure. Etiologies include:
• Pulmonary parenchymal or airway disease leading to hypoxemic vasoconstriction. Chronic obstructive lung disease (COPD), interstitial lung diseases, bronchiectasis, cystic fibrosis .
• Conditions that occlude the pulmonary vasculature. Recurrent pulmonary emboli, pulmonary arterial hypertension (PAH) , vasculitis, sickle cell anemia.
• Inadequate mechanical ventilation (chronic hypoventilation). Kyphoscoliosis, neuromuscular disorders, marked obesity, sleep apnea .



Symptoms 

Depend on underlying disorder but include dyspnea, cough, fatigue, and sputum production (in parenchymal diseases).

Physical Examination 

Tachypnea, RV impulse along left sternal border, loud P2, right-sided S4; cyanosis, clubbing are late findings. If RV failure develops, elevated jugular venous pressure, hepatomegaly with ascites, pedal edema; murmur of tricuspid regurgitation  is common.

Laboratory ECG

RV hypertrophy and RA enlargement ; tachyarrhythmias are common.

Radiologic Studies 

CXR shows RV and pulmonary artery enlargement; if PAH present, tapering of the pulmonary artery branches. Chest CT identifies emphysema, interstitial lung disease, and acute pulmonary embolism; V/Q scan is more reliable for diagnosis of chronic thromboemboli. Pulmonary function tests and ABGs characterize intrinsic pulmonary disease.

Echocardiogram 

RV hypertrophy; LV function typically normal. RV systolic pressure can be estimated from Doppler measurement of tricuspid regurgitant flow. If imaging is difficult because of air in distended lungs, RV volume and wall thickness can be evaluated by MRI.

Right-Heart Catheterization 

Can confirm presence of pulmonary hypertension and exclude left-heart failure as cause.

Cor Pulmonale TREATMENT

Aimed at underlying pulmonary disease and may include bronchodilators, antibiotics, oxygen administration, and noninvasive mechanical ventilation. For pts with PAH, pulmonary vasodilator therapy may be beneficial to reduce RV afterload . See  for specific treatment of pulmonary embolism. If RV failure is present, treat as heart failure, instituting low-sodium diet and diuretics; digoxin is of uncertain benefit and must be administered cautiously (toxicity increased due to hypoxemia, hypercapnia, acidosis). Loop diuretics must also be used with care to prevent significant metabolic alkalosis that blunts respiratory drive.