Definition. Abrupt drop in cardiac output as part of a pericardial compressive syndrome caused by an abnormal amount of intrapericardial fluid whose pressure exceeds the pressure of the heart chambers, hindering its filling.
Figure 36. From: Saito et al. Echocardiography 2008;25:321. A slow-growing effusion reaches the limit of pericardial stretch and thus the signs and symptoms of pericardial tamponade later than a fast-growing effusion.
Figure 37. From: Leimgruber, Circulation 1983;68:612.
Contrary to what was previously believed, it has been demonstrated that tamponade may appear progressively, not only abruptly. There is a progressive reduction of cardiac output which precedes the reduction of mean arterial pressure. The diastolic collapse of the RV free wall (RVDC) precedes overt tamponade (DCT).
Echocardiographic signs of pericardial tamponade.
Pericardial tamponade: progression of echocardiographic signs.