Cardiac compression with mitral stenosis: a haemodynamic challenge

The hemodynamics of pericardial restriction (diastolic equilibration of pressures in all the four chambers of heart) and that of mitral stenosis (presence of an end diastolic gradient between the left atrium and the left ventricle) appear mutually exclusive. We describe herein hemodynamic findings in two patients of rheumatic mitral stenosis associated with pericardial constriction in one patient and pericardial effusion with tamponade in the other. Disproportionate elevation of the pulmonary artery diastolic and wedge pressures as compared to the right atrial mean, and left and right ventricular end diastolic pressures was present in both patients. In constrictive pericarditis, the respiratory variation in pressure was reflected in the pulmonary artery wedge pressure but not in the left ventricular end diastolic pressure. The gradient between the pulmonary artery wedge pressure and the left ventricular end diastolic pressure was abolished completely during the inspiratory phase of respiration despite significant mitral stenosis. The difference in the pressure, however, was maintained throughout inspiration and expiration in pericardial effusion with tamponade. In patients with constrictive pericarditis and mitral stenosis, the pulmonary artery wedge pressure does not appear to be a true indicator of the left atrial pressure.