What is the difference between hibernating and stunned myocardium?
Stunned myocardium refers to viable myocardium with relatively preserved perfusion on SPECT or PET imaging, normal or decreased glucose metabolism on FDG PET imaging, and decreased wall motion on echocardiography. Stunning occurs in an acute ischemic event, but by the time the patient undergoes management and is referred for SMPI, blood flow has normalized so there is no perfusion defect even though wall motion is still impaired. The stunning should resolve as long as perfusion is maintained.
Hibernating myocardium refers to viable myocardium with decreased perfusion on SPECT or PET imaging, relatively preserved glucose metabolism on FDG PET imaging, and decreased wall motion on echocardiography. The implication is that chronic ischemia results in decreased flow and function, although the myocardium is still viable. Hibernating myocardium should respond well to attempts to revascularize the region, which would return flow and eventually reverse the functional deficits.