VALUE OF DOBUTAMINE NITRATE RADIONUCLIDE ANGIOGRAPHY IN PREDICTING REVASCULARIZATION EFFECTS ON VENTRICULAR-FUNCTION/

Objective. Dobutamine and Nitrate Radionuclide Angiography (RNA) may h elp to distinguish viable from nonviable myocardium and to predict rev ascularization effects on LV function. Setting. Ambulatory. Experiment al design. Prospective. Patients and methods, We studied 12 patients ( 11 male, 1 female; mean age 56 +/- 10 years) with three-vessel disease , severe LV dysfunction, and prior MI for a mean follow-up time of 10 +/- 3.4 months. Thallium-201 scintigraphy favored potential viability in all patients: inducible ischemia with satisfactory perfusion in mor e than one coronary arterial territory. Global and regional LVEF's wer e calculated from preoperative RNA (baseline rest study and with conti nuous dobutamine infusion with gradual rate increase plus oral nitrate s) and postoperative RNA at 1 and 6 months. Results. There was no oper ative mortality, but two late deaths occurred. Symptomatically, most p atients showed improvement. Global LVEF increased during dobutamine an d nitrates preoperatively (p <0.01), but not at 1 and 6 months postope ratively (without pharmacological intervention). Mean LVED volume was not significantly changed postoperatively. Regional EF improvement was found in 4 out of 9 LV wall segments under dobutamine and nitrates, a nd this increase persisted postoperatively at 1 and 6 months. Conclusi ons. Mild but significant increase in global LVEF during dobutamine an d nitrates administration is not predictive of postoperative LVEF impr ovement, However, regional EF improvement appears to be predictive of post-revascularization LV functional improvement.