Evaluation of Left Ventricular Function and Myocardial Wall Motion by Using Doppler Tissue Imaging After Arterial Switch Operation

Although arterial switch operation has become the first choice of treatment in patients with tran s pos ı t ı o n of great arteries, left ventricular function and myocardial wall motion abnormalities due to the transportation of coronary arteries are stili under investigation. Doppler tissue imaging can be used for evaluation of myocardial wall motion and contractility in various disease states. We investigated left ventricular size and function by using two dimensional, M-mode, Doppler and color Doppler echocardiography and measured the midmyocardial velocity of interventricular septum and left ventricular posterior wall during systolic ejection phase by Doppler tissue imaging in 21 patients, between 3 and 65 months, who had gone to arterial switch operation and in 16 normal children between 7 and 58 months. Left ventricu lar vo1ume was larger in patients (43.82±1 2.2 ml) than the normal children (37.72±7.76 ml) (p<0.05). Left ventricular mass was 81.5±17.2 g and 59.5±13.49 g in patients and normal children, respectively and the difference was s ignifican t (p<0.0005). T his diffe rence was more striking in patients who had two-stage operation. Left ventricular shortening fraction was within the normal range in most of the patients, and the mean value being 33.7±4.1% which was less than the control group (39±5%) (p<0.005). Ejection fraction and left ventricular circumferential shortening were also Jess than the control group. Accelerat ion time, ejection time, mean acceleration, acceleration time/ejection time ratio measured from the aortic Doppler flow were not different in patients and normal children. Twelve patients had mild and three had moderate neo-aortic valve regurgitation and all the patients with moderate regurgitation had two-stage operation. Interventricular septal motion was fo und to be paradoxical in I O of the patients by Doppler tissue imaging and the velocity of the posterior wall was greater than the normal children. In conclusion, although the elinical results of arterial switch operations are promising, there may be some differences of Jeft ventricular function and myocardial motion compared to normal children. Doppler tissue imaging is beneficial in th is group of patients for detection of myocard ial wall motion abnormalities.