Efficacy of technetium Tc 99m pyrophosphate imaging in patients with equivocal myocardial infarction.

We studied the efficacy of technetium Tc 99m pyrophosphate imaging in patients with equivocal evidence of acute myocardial infarction. Only patients with positive enzyme findings (regardless of ECG findings) had scans with greater than or equal to 2+ focal uptake. None of 26 patients with negative or equivocal enzyme findings (regardless of ECG findings) had greater than 2+ diffuse uptake. These results support the contention that infarct-avid imaging has little clinical utility in patients with equivocal evidence of myocardial infarction.