Myocardial viability assessed by positron emission tomography in infants and children after the arterial switch operation and suspected infarction

OBJECTIVES The aim of the studs was to assess regional glucose metabolism a nd contractile function by gated positron emission tomography using fluoro- 18-deoxyglucose (FDG-PET) in pediatric patients after the arterial switch o peration and suspected myocardial infarction. BACKGROUND Morbidity and mortality after the arterial switch operation for transposition of the great arteries are often related to impaired coronary function. Justification of high-risk revascularization procedure in infancy requires thorough evaluation of myocardial viability. Although PET is stat e-of-the-art for evaluation of myocardial viability in adults there are no reports on its impact and feasibility in infants and children. METHODS We applied electrocardiogram-triggered FDG-PET for assessment of me tabolic and functional status of the myocardium in seven infants and seven children. Glucose metabolism, wall motion and wall thickening were evaluate d visually and quantitatively on the basis of parametric 3-D images. Additi onally, single-photon emission computed tomography perfusion scan was perfo rmed in six children. RESULTS In two of seven infants, FDG-PET demonstrated viable myocardium in akinetic or hypokinetic regions corresponding to a coronary artery stenosis or occlusion. Therefore, indication for revascularization was derived from this finding. In six of the seven children, impaired glucose uptake reflec ting myocardial scarring was present. Two patients had pathological finding s on coronary angiography and signs of ischemia but were not suitable for r evascularization. CONCLUSIONS Myocardial viability and contractile function can be assessed s imultaneously by gated FDG-PET even in infant hearts. This method contribut es pertinent information to guide further therapy after the arterial switch operation and suspected myocardial infarction. (C) 2000 by the American Co llege of Cardiology.