A new quantitative mapping criterion to localize the ablation target of right ventricular outflow tract arrhythmias

(1) To explore the electrophysiological characteristics of the bipolar and unipolar electrogram (UEGM) of ablation targets for RVOT arrhythmias. (2) To optimize the diagnostic criteria of RVOT arrhythmia ablation targets.

A consecutive series of 111 patients with RVOT arrhythmias who underwent radiofrequency catheter ablation (RFCA) were studied. The voltage of bipolar potential for ablation targets were evaluated by three-dimensional voltage mapping procedure. The max slope of the descending limb (MSDL)、local activation preceding time (LAPT), the interval of the descending limb (IDL) and the interval of MSDL (IMSDL) of the unipolar potential were then calculated and analyzed for successful targets(ST) and failed targets(FT)groups. Successful ablation was achieved in 102 patients and 9 patients failed. LAPT was higher in the ST group than that in FT group (30.0 ± 4.3 ms vs 22.8 ± 6.3 ms, P < 0.001). IMSDL was lower in the ST group than that in FT group (9.93 ± 6.32 ms vs 21.7 ± 16.1 ms, P < 0.001). IMSDL and LAPT have a predictive value for a ST (AUC 75% and 83.7%). The optimal cut off value for LAPT and IMSDL were 24.5 ms and 20 ms respectively. A better predictive value can be acquired when IMSDL and LAPT were used in combination (AUC 93.9%, Sensibility/Specificity 92.3%/84.2%).

A combined use of LAPT and IMSDL may be helpful as an additional criterion for ST judgement.