Simultaneous assessment of myocardial glucose metabolism and contractile function by gated F-18-deoxyglucose positron emission tomography in infants after arterial switch operation for D-transposition of the great arteries

The arterial switch operation is now the treatment of choice for anatomic c orrection of dextro-transposition of the great arteries (D-TGA) in infancy. Early and late morbidity and mortality are related in part to impaired cor onary perfusion due to stenosis, compression, kinking, or occlusion of the transferred coronary arteries. To guide further therapy in these patients, evaluation of myocardial viability in akinetic or hypokinetic regions is re quired. F-18-deoxyglucose positron emission tomography (FDG-PET) is well-es tablished for the investigation of myocardial viability in adults. However, there are no reports about the impact of FDG-PET in infants. We applied EG G-triggered (7-12 gates) PET using a 30-min protocol for complete assessmen t of the metabolic and functional status of the myocardium in five infants with suspected or confirmed myocardial injury after the arterial switch ope ration. Left ventricular (LV) dysfunction was present in four infants. Coro nary angiography revealed stenosis or occlusion of one or more coronary ves sels in three patients. F-18-FDG (5-7 Mbq/kg) was injected after stimulatio n of glycolysis. Gated data acquisition was started 30 minutes after inject ion for a 20-min emission period, followed by a 10-min transmission. Glucos e metabolism, wall motion, and wall thickening were evaluated visually and quantitatively from parametric 3-D images generated by a new software for w all delineation. In one infant with severely impaired LV function, PET demo nstrated viable myocardium in hypokinetic regions except for a small non-tr ansmural infarction in the apex, providing an objective indication for surg ical revascularization. Another infant with severe stenosis of the left cor onary artery showed no metabolic abnormality and was scheduled for coronary angioplasty. A third patient with kinking of the left and right coronary a rteries had a large transmural defect corresponding to an apical and anteri or infarction. These preliminary results suggest that myocardial viability and contractile function can be assessed simultaneously by gated FDG-PET in order to guide further therapy in infants with coronary stenosis or occlus ion. (C) 1998 Elsevier Science Ireland Ltd. All rights reserved.