A Striking Case of Perfusion-Metabolism "Flip-Flop" in a Patient With Left Anterior Descending Artery Total Occlusion

A 57-year-old man diagnosed with left anterior descending artery chronic total occlusion underwent rest gated 99mTc-MIBI scan showing moderately to markedly decreased perfusion with abnormal wall motion in the apex, anterior, anteroseptal, and apical anterolateral walls. 18F-FDG PET showed a "flip-flop" phenomenon with markedly increased FDG uptake in the hypoperfused regions and absent/markedly decreased uptake in the normally perfused, normokinetic myocardium, presumably due to the predominant use of free fatty acids under normoxic conditions. After coronary artery bypass grafting, left ventricular motion normalized except for surgery-related paradoxical septal motion and the left ventricular ejection fraction improved from 52% to 68%.