Enlarged heart. X-ray of the chest of a 46-year-old patient with cardiomegaly (enlarged heart). The heart is the mass at lower right of the spine (running down centre). Cardiomegaly can be symptomless and is often only detected on a chest X-ray. The enlarged heart is often a response to excessive strain, such as obesity or a weakening of the heart muscle (cardiomyopathy), leading to heart failure. It can be treated with drugs and, as a last resort, a heart transplant.