Effect of dobutamine-induced myocardial ischemia on Doppler echocardiography after myocardial infarction.
Doppler echocardiography was performed during dobutamine stress test in 133 patients who had myocardial infarction. This investigation focused on the changes in the Doppler-derived left ventricular filling profile and hemodynamic measurements during ischemia. Patients were classified into two major groups on the basis of left ventricular ejection fraction (group 1, left ventricular ejection fraction > or = 40%, n = 66; group 2, left ventricular ejection fraction < 40%, n = 67) and then divided into the ischemic subgroup (1 A [n = 36] and 2A [n = 30]) and the scar subgroup (1 B [n = 36] and 2B [n = 31]) according to the presence or absence of dobutamine-induced myocardial ischemia. In group 1, the only Doppler echocardiographic measurement sensitive enough to differentiate ischemia was the corrected isovolumic relaxation time, which was significantly prolonged in group 1 A compared with group 1 B at peak stress (108 +/- 29 vs 82 +/- 30 msec, p = 0.005). The patients in group 2A had lower increases in stroke volume (-2% +/- 27% vs 22% +/- 33%, p = 0.002) and cardiac output (45% +/- 51 % vs 72% +/- 50%, p = 0.04) than those in group 2B, but larger increases in mitral peak early filling velocity (24% +/- 56% vs 0.9% +/- 37%, p = 0.02) and peak early to atrial velocity ratio (39% +/- 127% vs -24% +/- 38%, p = 0.01) than those in group 2B. The analysis of the changes that occurred in these parameters provides better insight into left ventricular diastolic and systolic function during dobutamine stress tests in patients after myocardial infarction.
Wang
C H
CH
Department of Medicine, Chang Gung Medical College, Chang Gung Memorial Hospital, Keelung, Taiwan, Republic of China.
Cherng
W J
WJ
Hung
M J
MJ
D000368:Aged; D002316:Cardiotonic Agents; D004280:Dobutamine; D015150:Echocardiography, Doppler; D005080:Exercise Test; D005260:Female; D006439:Hemodynamics; D006801:Humans; D008297:Male; D008875:Middle Aged; D009203:Myocardial Infarction / Q000503:physiopathology*; D015588:Observer Variation; D013318:Stroke Volume; D015899:Tomography, Emission-Computed, Single-Photon; D016277:Ventricular Function, Left
D002316:Cardiotonic Agents; D004280:Dobutamine