best cardiac doctors in yelahanka Cardiac enlargement, also known as cardiomegaly, refers to the abnormal enlargement of the heart. It can be identified through imaging tests like X-rays or echocardiograms and is often a sign of underlying conditions, such as heart disease, hypertension, or heart valve issues. Causes of cardiac enlargement include: Hypertension (High Blood Pressure): Increased blood pressure makes the heart work harder, leading to thickening and enlargement of the heart muscles. Heart Valve Disease: Improperly functioning valves can cause the heart to work harder, resulting in enlargement. Cardiomyopathy: Diseases of the heart muscle can lead to an increase in heart size.