M-mode echocardiogram showing respiratory motion of the interventricular septum in cardiac tamponade such that during inspiration, the right ventricle enlarges, and the left ventricle becomes smaller.
RV-I: right ventricle in inspiration; RV-E: right ventricle in expiration; LV-I: left ventricle in inspiration; LV-E: left ventricle in expiration.
Reproduced by permission of the American Heart Association from Settle, et al. Circulation 1977; 56:951.