Q. What is pericardial effusion?

A pericardial effusion is viewed as an echo free space surrounding the heart, most commonly seen posteriorly. Echocardiography provides a semiquantitative assessment of pericardial efision and a qualitative description of its distribution. It can be quantified into small, moderate and large pericardial effusion. A small pericardial effusion is defined as less than 5mm in maximum dimension. Moderate pericardial effusion typically are 10-15mm in dimension and tends to be more circumferential. Large effusions are defined as more than 15mm. When amount of pericardial efision is massive, the heart may have "swinging" motion in pericardial cavity.