What is cor pulmonale?

Cor Pulmonale is increased strain on the right side of the heart due to lung diseases that increase the pressure of the blood flowing through the lungs. The right ventricle tries to push blood through the diseased and usually scarred lung via vessels called pulmonary arteries, but has trouble doing this because of the scarring, resulting in increased pressure in the artery and therefore the right ventricle. The right ventricle compensates by getting bigger, and ultimately stops working so well.