Enlargement of the heart refers to an increase in the size of the atria and ventricles of the heart, or both atria and ventricles, causing a change in the shape of the heart, and is most commonly seen in various types of cardiac insufficiency or heart failure. Patients may experience compensatory enlargement due to ischemia of the heart, usually between coronary atherosclerotic heart disease, myocarditis, or heart failure, hypertensive heart disease, or even malnutrition. Especially for viral myocarditis, or congenital heart disease, hypertrophic obstructive cardiomyopathy, there will be typical clinical symptoms of heart enlargement, which can be clearly diagnosed by cardiac ultrasound.