The use of echocardiography in determination of reversible posterior wall asynergy.

Recent studies have indicated that nitroglycerin can be delineate potentially reversible asynergic zones depicted ventriculographically. To assess the ability of the echocardiogram to detect reversible asynergy, posterior wall motion was assessed in 19 patients both echocardiographically and ventriculographically before and after nitroglycerin. Thirteen of the 19 patients demonstrated abnormal posterior wall motion both by echocardiography and ventriculography while six were normal by both techniques. In 4 of the 13 asynergic areas, posterior wall excursion improved following nitroglycerin (from 0.99 +/- .07 to 1.30 +/- .07 cm. by echocarciography (p less than .025) with a corresponding improvement in hemiaxis shortening from 12.0 +/- 6.1 per cent to 29.0 +/- 6.7 per cent (p less than .02). In contrast, in nine patients in whom inferior segment hemiaxis shortening was unchanged following nitroglycerin, posterior wall excursion by echocardiography was similarly not improved (1.01 +/- .03 cm. before and 1.02 +/- .03 cm. after nitroglycerin). The effect of nitroglycerin on posterior wall velocity paralleled changes in posterior excursion. The six patients with initially normal posterior excursion showed no significant change by either echocardiography or ventriculography following nitroglycerin. Thus, the echocardiogram is of considerable value in detecting both the presence and potential for improvement of asynergic posterior wall segments.