Chest X-ray showing left ventricular hypertrophy, the enlargement of the heart caused by an increase in size of the walls of the left ventricle, the heart's largest pumping chamber. The enlarged heart appears as the central white mass that bulges to right of image. The term hypertrophy describes an increase in the size of an organ due to the enlargement of its constituent cells rather than by cell multiplication. Left ventricular hypertrophy may occur as a result of heart valve diseases, where an increase in thickness of the heart muscle allows it to beat more strongly to compensate for the increased strain placed upon it.