causes of left ventricular enlargement
Other medical conditions are less frequent causes of left atrial enlargement. For example, a ventricular septal defect -- a hole in the wall that separates the right and left ventricles -- can alter blood flow through the heart such that there is overfilling and enlargement of the left atrium.
Valvular Heart Disease. Disorders of certain heart valves can also lead to left atrial enlargement. The mitral valve separates the left atrium from the left ventricle. If the mitral valve becomes narrow -- a condition known as mitral stenosis -- blood accumulates in the left atrium and causes enlargement.