Subacute (elastic)
|
Chronic (rigid shell)
|
Paradoxical pulse usually present, other signs of interdependence usually prominent | Paradoxical pulse usually minimal or absent, other signs of interdependence less prominent |
| |
Usually an XY waveform (“M” or “W” waveform) | Y is predominant, X sometimes minimal |
| |
Dip–plateau pattern less conspicuous, because early diastolic nadir may not approach zero | Dip–plateau usually conspicuous, because early diastolic nadir often reaches zero |
|
| |
Calcification usually absent | Calcification often present |
| |
Pericardial effusion sometimes present, generalised or loculated. Constriction is by the visceral pericardium | Pericardial effusion absent. The two layers of pericardium are fused, and jointly constrict the heart |
| |
P waves usually normal | P waves often wide, notched and low in amplitude |
| |
Atrial fibrillation or flutter rare | Atrial fibrillation or flutter common |