The syndrome of cardiac tamponade with "small" pericardial effusion.

Cardiac tamponade is usually a consequence of increased pericardial pressure with accumulation of pericardial effusion. Pericardial effusion may be caused by acute pericarditis, tumor, uremia, hypothyroidism, trauma, cardiac surgery, or other inflammatory/noninflammatory conditions. In this article we describe four scenarios illustrated by case reports where a small or apparently small pericardial effusion may produce cardiac tamponade.