Two-dimensional contrast echocardiography. II. Transpulmonary studies.

A method using contrast two-dimensional echocardiography for left ventricular chamber and myocardial opacification from a right-sided pulmonary capillary wedge position is described. A total of 152 studies were carried out in nine mongrel dogs. Four different catheters with different catheter tip cross-sectional areas (varying from 0.75 to 2.3 mm2) were used. In addition, catheter position (six different positions in the pulmonary circulation), pressure of injection and type of echo contrast agent (hand-agitated and sonicated) were studied. In all 152 studies, two independent observers agreed that echo contrast was seen in the left ventricular chamber after a pulmonary capillary wedge injection of 8 cc of echo contrast agent followed by a flush injection of 8 cc saline solution. In 71% of the studies, the two independent observers agreed about the degree of opacification on a qualitative scale of 0 to 3+. Time from injection from the catheter tip to the appearance of echo contrast in the left atrium was 6.2 +/- 4.8 seconds for sonicated Renografin-76 and 2.8 +/- 0.6 seconds for sonicated sorbitol 70% (p less than 0.05). Correlation for the disappearance rate of echo contrast as determined for the region in the mid left ventricular chamber and thermodilution cardiac output was fair (r = -0.78; n = 14). In 24 studies, it was not possible to demonstrate the appearance of echo contrast in the myocardium. Peak videointensity of 10 duplicate injections showed a mean percent error of 10.4 +/- 2.1% for sonicated Renografin-76 and 1.4 +/- 0.8% for sonicated sorbitol 70%.(ABSTRACT TRUNCATED AT 250 WORDS)