Hemodynamic Phenomenon of Diastolic Superior Vena Cava Collapse in Constrictive Pericarditis

Constrictive pericarditis represents a condition of diastolic heart failure resulting from pericardial fibrosis and calcification, which imposes a rigid constraint on cardiac filling. While ventricular interdependence and equalization of diastolic pressures are well-recognized hemodynamic features, the behavior of the systemic veins proximal to the heart has received limited systematic investigation. The superior vena cava, particularly its intrapericardial segment, is exposed to the same pressure variations that affect the cardiac chambers and may undergo dynamic collapse during early diastole when transmural pressure becomes sufficiently negative.