The response of the heart and pulmonary arteries to hypoxia, pressure, and volume. A short review.

The pulmonary arterioles react to hypoxia by contraction and to increased pressure and volume by hypertrophy of the muscular wall, referred to as pulmonary vascular remodeling, both of which increase vascular resistance and result in increased pulmonary arterial pressure. Heart muscle reacts to increased pressure by hypertrophy of cardiac myocytes and thickening of the muscular wall. The heart responds to increased volume by dilation of the chamber that may result in physiologic or pathologic hypertrophy of the muscle wall. Heart muscle cells are very sensitive to hypoxia or other insults, and this may result in death of individual cardiac myocytes with lengthening and thinning of the remaining heart muscle cells and dilation of the chamber in a process called dilated cardiomyopathy.