INTRODUCTION AND OBJECTIVES: To determine the predictors of successful radiofrequency current ablation of an accessory pathway using the single-catheter approach, we retrospectively analyzed 46 consecutive patients with left sided accessory atrioventricular pathways and manifest preexcitation. METHODS: Ablation using a single catheter advanced retrogradely towards the mitral valve was successful in 42 (91%). A radiofrequency pulse resulting in permanent accessory pathway block was defined as a successful pulse; a pulse that had no effect or caused only transient accessory pathway block was defined as an unsuccessful pulse. RESULTS: Successful radiofrequency pulses (n = 37) did not differ from those that failed (n = 56) in the local atrium-accessory pathway potential interval, in the accessory pathway-ventricle interval nor in the cumulative energy delivered. But in successful radiofrequency pulses, the amplitude ratio of local atrium and ventricular potentials tended to be larger (0.29 +/- 0.17 vs 0.23 +/- 0.17; p = 0.053) and presumed accessory pathway potential was more often recorded (36 [97%] vs 38 [68%]; p = 0.006). The time elapsed from the beginning of the current application and the accessory pathway block was shorter in successful pulses as compared to those pulses producing only transient block (3.3 +/- 2 s vs 6.9 +/- 4 s). CONCLUSIONS: The recording of a presumed accessory pathway potential, a large local A/V ratio and the occurrence of early conduction block in the accessory pathway were the best predictors of successful radiofrequency current application using the single-catheter approach.
INTRODUCTION AND OBJECTIVES: To determine the predictors of successful radiofrequency current ablation of an accessory pathway using the single-catheter approach, we retrospectively analyzed 46 consecutive patients with left sided accessory atrioventricular pathways and manifest preexcitation. METHODS: Ablation using a single catheter advanced retrogradely towards the mitral valve was successful in 42 (91%). A radiofrequency pulse resulting in permanent accessory pathway block was defined as a successful pulse; a pulse that had no effect or caused only transient accessory pathway block was defined as an unsuccessful pulse. RESULTS: Successful radiofrequency pulses (n = 37) did not differ from those that failed (n = 56) in the local atrium-accessory pathway potential interval, in the accessory pathway-ventricle interval nor in the cumulative energy delivered. But in successful radiofrequency pulses, the amplitude ratio of local atrium and ventricular potentials tended to be larger (0.29 +/- 0.17 vs 0.23 +/- 0.17; p = 0.053) and presumed accessory pathway potential was more often recorded (36 [97%] vs 38 [68%]; p = 0.006). The time elapsed from the beginning of the current application and the accessory pathway block was shorter in successful pulses as compared to those pulses producing only transient block (3.3 +/- 2 s vs 6.9 +/- 4 s). CONCLUSIONS: The recording of a presumed accessory pathway potential, a large local A/V ratio and the occurrence of early conduction block in the accessory pathway were the best predictors of successful radiofrequency current application using the single-catheter approach.