A PROSPECTIVE, RANDOMIZED COMPARISON OF TEMPERATURE-CONTROLLED VS MANUALLY DELIVERED RADIOFREQUENCY CATHETER ABLATION IN PATIENTS UNDERGOING ATRIOVENTRICULAR NODAL MODIFICATION OR ACCESSORY PATHWAY ABLATION

Aims In a prospective, randomized study, the effect of temperature con trol on radiofrequency catheter ablation was compared in 69 patients u ndergoing atrioventricular nodal modification (n = 32) or ablation of an accessory pathway (n = 37) Methods and results Thirty-five patients were randomized to temperature control, 34 to manually delivered radi ofrequency ablation. The success rate was 92.5% for accessory pathway ablation and 100% for atrioventricular nodal modification. Mapping dur ation was significantly reduced only in patients undergoing atrioventr icular nodal modification. The number of applications was higher for m anually delivered ablation in patients undergoing atrioventricular nod al modification (5.6 +/- 1.1 vs 1.9 +/- 0.4, P = 0.004) as was the cum ulative energy delivered (5034 +/- 1008 vs 2054 +/- 517 W, P = 0.013) whereas the mean power per application was higher with temperature con trol (41.4 +/- 1.8 vs 34.1 +/- 1.1 W, P = 0.002). No significant diffe rences in these parameters were found in patients undergoing accessory pathway ablation. Coagulum formation on the catheter tip was observed more often with manually delivered ablation 5.3% vs 0.9%, P = 0.026). The success rate with the initially randomized application mode was h igher for temperature control (94.3 vs 61.8%, P = 0.003). Conclusions Temperature control during radiofrequency current ablation significant ly reduces mapping duration, necessary applications and cumulative ene rgy in atrioventricular nodal modification, but not accessory pathway ablation. Coagulum formation on the catheter tip still occurs but is s ignificantly reduced compared to manually delivered radiofrequency cur rent.