Author + information
- Received November 10, 1993
- Revision received May 9, 1994
- Accepted June 2, 1994
- Published online November 1, 1994.
- Gianni Bisi, MD∗,
- Roberto Sciagrà, MD,
- Giovanni M. Santoro, MD and
- Pier Filippo Fazzini, MD
- ↵∗Address for correspondence: Dr. Gianni Bisi, Nuclear Medicine Unit, Department of Clinical Pathophysiology, University of Florence, Viale Morgaeni 85, 50134 Florence, Italy.
Objectives. This study investigated the role of nitrite technetium-99m sestamibi imaging in predicting the postrevascularization outcome of chronically hypoperfused asynergic territories.
Background. Rest technetium-99m sestamibi myocardial scintigraphy underestimates the presence of viable myocardium in asynergic territories. Stimulation that improves coronary blood flow could increase tracer uptake in hibernating territories.
Methods. Nineteen patients with a previous myocardial infarction and left ventricular dysfunction scheduled for revascularization underwent quantitative technetium-99m sestamibi tomography under baseline conditions and during isosorbide dinitrate infusion. Global and regional function were assessed, respectively, before and after revascularization by radionuclide angiocardiography and two-dimensional echocardiography.
Results. Seven patients (group A) showed postrevascularization regional function recovery, and 12 (group B) showed no significant changes. In group A, nitrate infusion induced a decrease in the extent of the global uptake defect ([mean ± SD] −37.4 ± 21.6% of baseline value); in group B, ne change or a slight increase was observed (+5.8 ± 8.4%, p < 0.0005 vs. group A). The nitrate-induced changes in the extent of uptake defect correlated with postrevascularization changes in ejection fraction (r = −0.94, SEE 7.6). After revascularization, 11 asynergic vascular territories showed improvement (hibernating), and 34 remained unchanged (fibrotic). With administration of nitrates, 10 hibernating territories had a decrease in the extent of uptake defect, whereas only 4 of 34 of the fibrotic territories showed a nitrate-induced uptake improvement.
Conclusions. Short-term administration of isosorbide dinitrate immediately before injection of technetium-99m sestamibi increases tracer uptake in some chronically hypoperfused asynergic territories. This finding correlates with the observation of postrevascularization functional recovery. Nitrate technetium-99m sestamibi myocardial scintigraphy could be a promising method for the noninvasive detection of viable hibernating myocardium.
- Received November 10, 1993.
- Revision received May 9, 1994.
- Accepted June 2, 1994.