Objective: This study sought to investigate whether low-dose dobutamine-MRI can detect residual myocardial viability in patients with chronic myocardial infarction and, left ventricular dysfunction.
Methods: Eleven patients with chronic myocardial infarction and left ventricular dysfunction were employed for identification of viable myocardium by cine-MRI during dobutamine infusion. All patients underwent coronary angiography and left ventriculography, 18FDG-PET, MRI at rest and stress. The systolic wall thickening measured at rest and during stress was compared with the results of 18FDG-PET, respectively.
Results: A significant difference of either dobutamine-induced systolic wall thickening (SWthstress) or dobutamine-induced contractile reserve (deltaSWth = SWthstress - SWthrest) was present between viable and scar regions (1.0 +/- 0.3 versus -0.3 +/- 0.1, P < 0.01; 1.0 +/- 0.3 versus -0.2 +/- 0.2, P < 0.01).
Conclusions: obutamine-induced contractile reserve can be predicted in the regions of akinesia or dyskinesia at rest when systolic wall thickening was > or = 1.0 mm during dobutamine stimulation.