Case history: A 79-year-old woman suffered an acute inferior wall myocardial infarction and underwent cardiac catheterization for postinfarction angina. Her coronary angiogram revealed a 90% stenosis of the mid left anterior descending coronary artery, a 60% stenosis of the first obtuse marginal branch of the left circumflex coronary artery and a proximally occluded right coronary artery. Cardiac ultrasound revealed an akinetic inferior wall and severe hypokinesis of all other walls with an estimated global ejection fraction of 20% to 25%.
Clinical dilemma: With this patient's coronary anatomy, options for revascularization included multivessel bypass surgery or single vessel coronary angioplasty. The decision depended on the viability of the inferior wall. If the inferior wall was nonviable, single vessel coronary angioplasty of the left anterior descending coronary artery would be the revascularization procedure of choice. On the other hand, a viable jeopardized inferior wall myocardium would favor complete revascularization with coronary bypass surgery.
Dipyridamole myocardial perfusion SPECT imaging with 99roTe-labeled sestamibi using a 1-day protocol was used to determine which vessels supplied jeopardized viable myocardium and how much viable myocardium was present. The patient had mild chest discomfort during the dipyridamole infusion, but had no associated ECG changes. The resultant images (Figure 1) revealed a reversible anterior defect and a partially reversible inferior defect.
Conclusions: With jeopardized viable myocardium in the distributions of the left anterior descend-