Demonstration of Viable, Stunned Myocardium with Technetium-99m-Sestamibi

Delayed improvement of left ventricular contractile function in the setting of acute ischemia followed by reperfusion ("stunned myocardium") has been observed in a number of clinical scenarios, and may have important clinical implications. At present, there are no widely accepted techniques available to demonstrate its presence. We report a case in which a rest 99mTc-sestamibi scan performed 12 hr after thrombolytic therapy in the setting of acute myocardial infarction demonstrated viable myocardium in a region that was akinetic by contrast ventriculography. After surgical revascularization, follow-up 99mTc-sestamibi images showed normal perfusion and radionuclide ventriculography demonstrated normal left ventricular function. Demonstration of preserved 99mTc-sestamibi myocardial uptake in the infarct zone despite an extensive region of akinesis by contrast ventriculography predicted the recovery of left ventricular function after revascularization in this case. This suggests that perfusion imaging with 99mTc-sestamibi early after myocardial reperfusion can detect stunned myocardium and thus facilitate the decision-making process regarding management of such patients.