An Experimental Echocardiographic and Hemodynamic Study

after heart surgery is fre-quently associated with localized pericardial effusion. P34houghright ventricular diastolic collapse and right atrial collapse arereliable ecbrcardiographic findings in patients with circumferenltial pericardial effusion and tamponade, they are often not presentin postoperative patients with localized pericardial effusion andregional left heart tamponade. Left ventricular diastolic collapsehas been described in such patients, but the degree of hemody-namic alteration that exists with this finding is not known .Methods. Acute regional left heart tamponade was produced 14times in seven spontaneously breathing anesthetized dogs byinfusing fluid into an isolated compartment created in the peri-cardial space adjacent to the left ventricular free wall . Continuousechocardlographic imaging and hemodynamic monitoring of leftventricular, systemic arterial, right atrial, pulmonary capillarywedge and pericardial pressures were performed. MeasurementsPericardial effusion is a frequent event after cardiac surgery,occurring in -85% of pzlients (1). Fortunately, it is usuallyuncomplicated and reso' les spontaneously. Cardiac tam-ponade