STRESS-INDUCED LEFT-VENTRICULAR DYSFUNCTION IN SILENT AND SYMPTOMATIC MYOCARDIAL-ISCHEMIA DURING DOBUTAMINE STRESS TEST

The extent and severity of dobutamine-induced left ventricular (LV) dysfunction with and without angina were evaluated in 105 consecutive patients with significant coronary artery disease and a positive dobutamine stress echocardiographic test, defined as new or worsening wall motion abnormalities during high-dose dobutamine stress (up to 40 mu g/kg/min). Wall motion score (WMS) was derived using a 16-segment, 4-grade scoring method. The difference between stress and rest WMS (Delta WMS) was derived as a global measure of stress-induced LV dysfunction. Typical angina occurred in 61 patients (58%) during the test. There was no significant difference between patients with or without angina with respect to age, gender, prevalence of previous myocardial infarction, multivessel disease, or number of diseased coronary arteries. Patients with angina had a higher prevalence of a history of angina before the test, Rest, stress, and Delta WMS, number and distribution of ischemic segments, and number of segments with an increase in regional WMS of greater than or equal to 2 were not significantly different in patients with or without angina. ST-segment depression was more frequent in patients with angina (56% vs 29%, p <0.05). Patients with (vs those without) ST-segment depression had a significantly higher number of ischemic segments with normal baseline contraction, an equal total number of ischemic segments, and a similar Delta WMS. It is concluded that in patients with anatomically and functionally significant coronary artery disease, the amount of stress-induced LV dysfunction evaluated by dobutamine stress echocardiography is similar in patients with or without angina. ST-segment depression is more common in patients with angina and is associated with more extensive ischemia in normally contracting segments at rest.