RELATION OF CONTRACTILE RESERVE DURING LOW-DOSE DOBUTAMINE ECHOCARDIOGRAPHY AND ANGIOGRAPHIC EXTENT AND SEVERITY OF CORONARY-ARTERY DISEASEIN THE PRESENCE OF LEFT-VENTRICULAR DYSFUNCTION

Contractile reserve, during low-dose dobutamine echocardiography, is f requently used for the assessment of myocardial viability in patients with coronary artery disease (CAD) and left ventricular (LV) dysfuncti on. Whether contractile reserve is affected by the severity of the und erlying CAD is presently unknown. Accordingly, we studied 58 patients with stable CAD and LV dysfunction who underwent coronary angiography and low-dose dobutamine echocardiography. In each vascular region the worst stenosis was identified and quantitated as percent diameter sten osis. Segmental wall motion during echocardiography was scored visuall y and rest and dobutamine wall motion score indexes were calculated. C ontractile reserve was defined as greater than or equal to 1 grade imp rovement in wall motion score of greater than or equal to 2 contiguous segments along with greater than or equal to 20% reduction in global wall motion scare index with dobutamine. There was no difference betwe en patients with (n = 26) and without (n = 32) contractile reserve in percent coronary stenosis (89 +/- 17% vs 87 +/- 17%, p = 0.6), number of coronary arteries with > 50% diameter stenosis (2.0 +/- 0.8 vs 2.2 +/- 0.7, p = 0.4), number of occluded coronary arteries (1.2 +/- 0.9 v s 1.1 +/- 0.9, p = 0.6), or the prevalence of collaterals demonstrated angiographically (61% vs 56%, p = 0.5). Our data demonstrates that in patients with CAD and LV dysfunction, the prevalence of contractile r eserve during low-dose dobutamine echocardiography is independent of t he angiographic extent and severity of CAD. (C) 1997 by Excerpta Medic o, Inc.