Echocardiography in the differential diagnosis of the large heart.

Echocardiography is an extremely useful noninvasive technic in the differential diagnosis of a large heart. It may show whether a large heart is due to left ventricular hypertrophy or dilatation, or if it is due to a pericardial effusion. The hypertrophied heart may be further characterized by determining whether it is symmetrical, as caused by aortic stenosis or hypertension, or whether it is assymmetrical, which is characteristic of hypertrophic cardiomyopathy. Similarly, dilatation of the heart may be due to volume overload of the left ventricle secondary to valvular insufficiency, congestive cardiomyopathy or ischemic heart disease; these can be distinguished by echocardiography. As certain types of mitral insufficiency are associated with specific valvular dysfunction, the possible etiology of the mitral insufficiency and therefore of the volume overload of the left ventricle may be determined using echocardiography. Finally, mediastinal tumors may simulate a large heart, and demonstration of normal cardiac dimensions and wall motion can exclude a cardiac etiology for the "large heart."