The amrinone stimulation test. A diagnostic approach to the detection of myocardial viability

pp 257-268

Abstract

In order to detect the existence of "hibernating" myocardium, ejection fraction (EF) and wall motion score (WMS) were measured using a radionuclide angiography under basal resting conditions and 20 minutes after injection of I mg/kg amrinone iv. The test was made in 121 patients of whom 33 later received myocardial revascularization surgery (CABG). Three operated patients died. EF and WMS were measured in the remaining 30 at 20 days post-op. Three groups of patients were defined using the amrinone stimulation test (AST) on the basis of basal EF (EFB) and basal WMS (WMSb) and on the percentage changes in EF and WMS (D % EF, D % WMS) in response to AST. Group I: D % EF > 30 %, n = 15, classified as AST ( + ) positive. Group 2: D % EF < 30 % and D % WMS < 10 %, n=8, AST(-) negative. Group 3: D% EF < 30% and D%WMS> 10%, n=7, AST doubtful. Group I 10 patients improve EF after CABG. Group 2: only one patient improved and 7 no change or worsenet EF after CABG. Group 3: three patients improved EF after CABG and four patients worsenet. The EF post- CABG (EFq) versus EFb was: Group 1, X EFb 22.7 ± 7.7; X EFq 35.5 ± 8.5 (p < 0.001). Group 2, X EFb 31.5 ± 7.7; X EFq 31.8 ± 9.5 (p: ns). Group 3, X EFb 29.7 ± 6.7; X EFq 34.3 ± 4.5 (p: ns). We conclude that AST + indicates a myocardial viability reserve which can be activated by CABG.