Cor pulmonale is characterized by which cardiac change?

• A. Left ventricular enlargement
• B. Atrial fibrillation
• C. Pulmonary edema
• D. Right ventricular enlargement (hypertrophy or dilation)

Answer: (D)

Cor pulmonale is right-sided heart involvement caused by chronic lung disease and the resulting pulmonary hypertension. The primary cardiac adaptation is enlargement of the right ventricle due to increased afterload from the high pressures in the pulmonary circulation. This can start as hypertrophy and progress to dilation as the right ventricle struggles to move blood through the constricted pulmonary arteries. Over time, this leads to signs of right-sided heart failure, such asneck vein distension and peripheral edema.

Left ventricular enlargement is associated with conditions primarily affecting the left heart, not cor pulmonale. Atrial fibrillation is a rhythm disturbance, not the structural change defining cor pulmonale. Pulmonary edema tends to reflect left-sided failure or acute decompensation rather than the typical right ventricular remodeling seen in cor pulmonale. Thus, the characteristic cardiac change is right ventricular enlargement (hypertrophy or dilation).