DETECTION OF MYOCARDIAL VIABILITY BY ECHOCARDIOGRAPHY WITH DOBUTAMINEINFUSION 3 WEEKS AFTER MYOCARDIAL-INFARCTION

The aim of this study was to assess the value of low dose dobutamine ( 5 and 10 gammas/Kg/min) echocardiography for the detection of hibernat ing myocardium in an infarcted zone three weeks after the initial infa rction. The authors studied 23 patients (18 men, 15 women) with an ave rage age of 59 +/- 8 years before and 3 months after angioplasty of th e culprit artery. Segmental wall motion was assessed semi-quantitative ly by the criteria of the American Society of Echocardiography. All pa tients had regional contractile abnormalities under basal conditions a nd all underwent control coronary angiography at 3 months. Improvement of segmental wall motion with dobutamine predicted improvement after revascularisation with positive and negative predictive Values of 95% and 85% respectively. The sensitivity and specificity of the test calc ulated in the usual manner were 83% and 96% respectively. In addition, assessment of diastolic function showed reduction of the isovolumic r elaxation time with dobutamine only in patients with hibernating myoca rdium (120 +/- 30 ms decreasing to 114 +/- 29 ms with dobutamine, p< 0 .02). Low dose dobutamine echocardiography therefore allows reliable n on-invasive prediction of hibernating myocardium three weeks after inf arction. The reduction of isovolumic relaxation time with dobutamine c ould be an additional argument in favour of the diagnosis.