Doppler echocardiogram in cardiac tamponade

In cardiac tamponade, the Doppler echocardiogram shows respiratory variation of left-sided Doppler flow signals. Drift in electrocardiogram (ECG) baseline identifies respiration. Panel A is recorded from the left ventricular outflow tract; the arrows denote the peak forward velocity of each beat, demonstrating that respiration causes a change in velocity that exceeds 25 percent. Panel B is obtained from the mitral inflow; the large and small arrows are the E and A waves, respectively. The E and A waves change in amplitude with respect to each other within each beat (ie, E>A or A>E) and to their analogues in neighboring beats. The pattern of mitral inflow and E/A ratio are similar to those seen with the major types of diastolic dysfunction.