Which condition leads to eccentric hypertrophy of the ventricle?

Eccentric hypertrophy of the ventricle primarily occurs as a response to volume overload. This condition involves an increase in the ventricular chamber size along with a proportional increase in the mass of the myocardial muscle fibers.

In cases of volume overload, such as in heart valve regurgitation (e.g., aortic or mitral regurgitation) or in conditions like dilated cardiomyopathy, the heart compensates for the increased volume of blood that it needs to pump. As the volume of blood within the ventricle increases, the walls of the ventricle stretch to accommodate the larger volume. This leads to a remodeling process where the muscle fibers are added in series, resulting in greater chamber size and lengthening of the ventricle, characteristic of eccentric hypertrophy.

This contrasts distinctly with pressure overload, where the heart walls thicken due to an increase in the resistance the heart must work against (as seen in conditions like aortic stenosis or hypertension). In pressure overload, the heart muscle adapts primarily by hypertrophying (thickening) rather than expanding in volume.