Chronic Constrictive Pericarditis with peripheral edema : a case report

Constrictive pericarditis (CP) is a type of diastolic heart failure that occurs because the inelastic pericardium inhibits filling of the heart. The true population prevalence is unknown, but among those with viral pericarditis it is estimated to occur in less than %۰.۵ of cases۱. Although the cause of CP can be different (idiopathic, post-viral, tuberculosis, post-surgery, radiation-induced, etc). The last common pathway is the development of fibrous thickening or calcification of the pericardium, which leads to pericardial noncompliance ۲,۳.A normal pericardium minimally interferes with ventricular expansion at normal cardiac workloads. In CP, pericardial noncompliance creates a stiff ventricular-pericardial unit, leading to increased diastolic pressure and a faster rise in ventricular pressure for a given venous return. A noncompliant pericardium limits ventricular relaxation and determines ventricular diastolic pressure, resulting in high and uniform diastolic pressure in all chambers. Clinically, this presents predominantly as right-sided congestion. Increased pulmonary capillary wedge pressure and decreased cardiac output response to exercise lead to dyspnea and exercise intolerance, although overt pulmonary edema is less common than typical systolic heart failure.The normal pericardium adjusts the coupling of left and right stroke volumes during acute changes in preload, such that a sudden increase in right venous return increases. This in turn reduces LV end-diastolic volume (LV preload) and, therefore, left-sided volume. Due to the constant volume of the pericardium in CP, the pericardial coupling is greatly exaggerated, leading to a dramatic ventricular interdependence. Abnormal movement of the ventricular septum is caused by increased respiratory changes in left and right stroke volume۴.