Multipolar radiofrequency ablation: Early experience with a novel approach to target intramural ventricular arrhythmias.

BACKGROUND

Conventional radiofrequency ablation (RFA) may fail to treat ventricular arrhythmias (VAs) if the target is located deep within the myocardium. We have previously demonstrated successful treatment of intramural VAs using multipolar ablation (MPA).

OBJECTIVE

To evaluate the efficacy of MPA as a means to treat refractory VAs. Accordingly, we herein report a series of patients with refractory VAs treated with MPA.

METHODS

This observational retrospective case series included 31 consecutive patients who underwent 36 MPA procedures for premature ventricular contractions (n = 20) and ventricular tachycardia (n = 16). All patients exhibited evidence of intramural origin by defined mapping criteria. Two or more mapping electrodes were incorporated into the ablation circuit as return poles. Ablation-return configurations included left ventricle (LV) endocardium-LV epicardium, LV endocardium-right ventricle (RV) endocardium, and LV or RV endocardium-epicardial vein tributaries.

RESULTS

A total of 151 MPA lesions were delivered with an RFA of 60 s, power of 22 W, initial current of 379 mA, and impedance drop of 19 Ω. Technical limitations of lesion delivery included high impedance in coronary sinus branches and char formation on return electrodes. Acute success was observed in 34 cases (94%), near-term success in 25 cases (69%), and long-term success in 23 cases (70%). There were no major complications.

CONCLUSION

MPA may facilitate arrhythmia control in patients with intramural VAs. Nevertheless, additional studies are necessary to better evaluate MPA safety and efficacy profiles, with further preclinical work and larger clinical studies required.