Myocardial perfusion and angiographic correlations in patients with ST-segment elevation during dobutamine stress perfusion imaging.

BACKGROUND: There is scanty information on the angiographic and myocardial perfusion correlates of dobutamine-induced ST-segment elevation. METHODS AND
RESULTS: We studied 39 patients who exhibited ST-segment elevation during dobutamine perfusion tomography and had recent coronary angiography performed (ie, within 3 months of the dobutamine study). Baseline characteristics, extent of coronary artery disease, relationship of Q waves to ST-segment elevation, ischemic burden, and angiographic findings were assessed. Twenty-nine patients (74%) had prior myocardial infarction, and 77% had abnormal Q waves at baseline. Ninety-three percent of patients had abnormal perfusion imaging. Eighty percent of patients had multivessel coronary artery disease. The left ventricular ejection fraction by contrast ventriculography was 35% +/- 7% (mean +/- SD), the perfusion defect size was 32% +/- 15%, and 73% of patients had some degree of myocardial ischemia. A predominance of ischemia (>50% reversibility) occurred in 38% of patients with Q waves and in 70% of those without Q waves. There was also good agreement between the site of ST-segment elevation and the site of ischemia by perfusion imaging (79%) and between the site of ST-segment elevation and the location of the vessel with significant coronary stenosis (95%).
CONCLUSIONS: Patients with dobutamine-induced ST-segment elevation have a depressed left ventricular ejection fraction, a high frequency of multivessel disease, and markedly abnormal myocardial perfusion tomography. In patients with ST-segment elevation and abnormal Q waves, substantial scarring and superimposed ischemia coexist, whereas in patients without Q waves, ST-segment elevation usually denotes severe ischemia.