Temperature monitoring during radiofrequency catheter ablation of accessory pathways.

BACKGROUNDAnimal studies have suggested that the temperature of the electrode-tissue interface during radiofrequency catheter ablation accurately predicts lesion size. The purpose of the current study was to evaluate the utility of continuous temperature monitoring during radiofrequency catheter ablation in patients with Wolff-Parkinson-White syndrome.METHODS AND RESULTSTwenty patients with manifest preexcitation were included in the study. The ablation catheter was positioned on the ventricular side of the mitral annulus for left-sided accessory pathways and on the atrial side of the tricuspid annulus for right-sided and septal accessory pathways. A thermistor imbedded in the distal electrode of the ablation catheter allowed continuous temperature monitoring during each energy application. To define the relation between power and temperature, radiofrequency current was applied several times at each site using outputs of 20, 30, 40, and 50 W. The accessory pathways were successfully ablated in each of the...