ABSTRACT
Objective To evaluate the accuracy,practical value and methods of Doppler tissue imaging(DTI) in localizing the ventricular emergence site of accessory atrioventricular pathways.Methods Forty patients with pre-excitation syndrome were examined by DTI before intracardiac electrophysiologic studies(EP) and radiofrequency catheter ablation(RFCA).The pre-excitation zone was determined as a zone of maximum acceleration with “DTI acceleration mode” at the time of the delta wave or before the onset of the QRS complex.At the same time,the contraction velocity was measured from subendocardium of corresponding myocardial segment by “pulsed wave Doppler imaging”.Results Assuming the results of EP and RFCA as a gold standard,the correct localization by DTI was 80% but was only 47.5% and 52.5% by eletrocardiographic algorithms( P