133Bipolar ablation of refractory ventricular arrhythmias originating from the close proximity of His bundle

Abstract

Abstract Introduction Biophysics of bipolar radiofrequency catheter ablation (Bi-RFCA) suggest more condensed and selective lesion formation when compared to conventional-unipolar approach. Whether more selective Bi-RFCA can result in safe and effective ablation of arrhythmic substrates in close proximity of His bundle has not been investigated so far. Purpose To determine feasibility and effectiveness of Bi-RFCA in His bundle area. Methods Consecutive patients after failed unipolar ablation for symptomatic premature ventricular complexes (PVC) or ventricular tachycardia (VT) originating from the vincity of His bundle underwent Bi-RFCA. Results We ultimately enrolled 8 patients (2 females, age 60 ± 15 years) to undergo Bi-RFCA of PVC/VT. Previous pharmacological treatment consisting of at least one antiarrhythmic drug and conventional catheter ablation failed in all. Bi-RFCA using open-irrigated and non-irrigated ablation catheters (AC) was delivered from two earliest PVC/VT activation sites located in the vincity of His bundle (Figure, panels A-B). A total number of 93 bipolar applications were delivered (mean bipolar RF time 508 ± 565s, mean power 35 ± 13W, mean impedance 163 ± 18Ω). Transient conduction disturbances occurred in 2 patients and were associated with mechanical compression of conduction system. No persistent conduction disturbances occurred. Bipolar RFCA led to acute elimination of PVC/VT in 6 (75%) patients. Follow up lasted 11 ± 5 months: two patients underwent repeat procedure using dual-irrigated Bi-RFCA, there was no VT recurrence and 72% PVC burden reduction was achieved (16200 ± 11600 pre-ablation vs 4500 ± 6200 post-ablation PVC/day, p = 0,035) (Figure, panel C). Conclusion Bi-RFCA performed in proximity of His bundle can be safe and effective in majority of patients. Abstract Figure. Bipolar ablation of parahisian PVC/VT