[The identification of vital myocardium with the dopamine stimulation test: an intraoperative echocardiographic study]

The aim of this study was to detect by dopamine echocardiography dysfunctioning but viable myocardial segments. We have studied 19 patients with 3-vessel disease and chronic, stable angina pectoris. Patients were studied by intraoperative transesophageal echocardiography during coronary artery bypass surgery. The analysis of regional systolic function was performed utilizing the transgastric short-axis view at papillary muscle level and dividing the left ventricle in 8 segments, according to the recommendations of the American Society of Echocardiography. A total of 152 myocardial segments were analyzed. Percent systolic wall thickening was calculated in each segment at baseline (early after pericardiectomy), during dopamine infusion (5 mcg/kg/min) and 30 min after separation from cardiopulmonary bypass (after protamine administration). The administration of vasodilatory or inotropic drugs was avoided. The echocardiographic images were recorded on videotape and analyzed off-line by 2 independent observers. Segments showing at baseline percent systolic wall thickening < 30\% were considered dysfunctional (134/152 = 88\%). Eighty-four (63\%) of these segments, increasing during dopamine infusion percent systolic wall thickening > 10\% (from 12.9 +/- 3.5 to 20.7 +/- 5.4\%; p < 0.05) were considered responder. On the other hand, 50 segments (37\%) showing during dopamine an increment in percent systolic wall thickening < 10\%, were considered non-responder. After coronary surgery, responder segments showed a significant increase in percent systolic wall thickening in comparison with baseline values (from 12.9 +/- 3.5 to 22.1 +/- 4.3\%; p < 0.05). Segments non-responding to dopamine showed no significant changes in percent systolic wall thickening after myocardial revascularization.(ABSTRACT TRUNCATED AT 250 WORDS)