Transmural distribution of FDG uptake in stunned myocardium

Fasting [¹⁸F]fluoro-2-deoxyglucose (FDG) uptake is increased in viable, chronically dysfunctional myocardium, but the relationship to acute episodes of ischemia remains undefined. To investigate FDG uptake in acute stunning, chronically instrumented pigs (n = 9) and sham controls (n = 8) were studied while in a fasted, closed-chest, anesthetized state. One-hour partial occlusion reduced subendocardial flow from 1.24 ± 0.14 to 0.35 ± 0.06 ml · min^-1 · g-¹ and wall thickening from 16.8 ± 2.1 to 3.7 ± 0.7%. Regional function remained depressed during reperfusion (8.3 ± 1.4%) despite the return of flow to resting levels. Triphenyl tetrazolium chloride staining showed no irreversible injury. FDG uptake in stunned myocardium was variably increased and averaged 1.5-fold higher than that of normal regions, with no consistent transmural variation. Subgroup analysis showed that variability in FDG uptake was related to alterations in insulin levels that varied directly with ischemic risk region.