Echocardiographic study of cardiac tamponade.

We studied 14 patients with cardiac tamponade and pulsus paradoxus; 11 were studied after relief of tamponade by pericardiocentesis. Right ventricle diastolic diameter increased during inspiration in each of 12 patients; left ventricle diastolic diameter decreased during inspiration in each of 13. Mitral valve DE amplitude decreased with inspiration in 13 of 14 patients. Mitral valve E-F slope could be measured in eight patients, and was rounded and not measurable in six. Six of the eight showed inspiratory decrease in mitral E-F slope. Similar changes were observed in two other patients with pulsus paradoxus who had chronic obstructive airway disease. Twenty patients with large pericardial effusions and no tamponade did not show these changes. These results suggest inspiratory augmentation of right ventricular filling and inspiratory diminution of left ventricular filling, not only in cardiac tamponade, but in obstructive airway disease associated with pulsus paradoxus.