PO-04-029 TRIANGULATING THE LV SUMMIT: A NOVEL BIPOLAR RADIOFREQUENCY CATHETER ABLATION STRATEGY

Abstract

Bipolar radiofrequency catheter ablation (RFCA) is an off-label strategy used to target ventricular arrhythmias (VA) from difficult substrates such as the LV summit. To achieve greater transmural RFCA lesions in challenging anatomy with a novel bipolar RFCA strategy. N/A A 51-year-old male with familial HCM and prior catheter ablation for persistent AF presented with pallor and palpitations in the setting of wide complex tachycardia of 210 BPM (Figure A). The patient was given a bolus of IV amiodarone and externally cardioverted. Amiodarone was discontinued given his history of amiodarone-induced hyperthyroidism. During the hospitalization, he had recurrences of sustained VAs that were suppressed with lidocaine. Cardiac MRI was obtained, which showed LVEF 42% and an extensive LGE in the LV (Figure B). The patient was brought to the EP lab for VT ablation. Extensive mapping in the RVOT, distal CS, and peri-aortic area was performed. The best pacemap was achieved with the 2F EPstar catheter (Baylis Medical) in the AIV. The ablation catheter was not able to be advanced into the distal branch in the coronary sinus. A total of 17 unipolar RFCA lesions were delivered from endocardial LV but the clinical VA remained easily inducible. A second ablation catheter was advanced to the posteroseptal RVOT on the opposite side of the septum for bipolar RFCA. The 2F EPstar catheter was positioned in the AIV near the region of best pacemap for tripolar effect (Figure C). A significant difference in the ablation impedance decline was noted between unipolar and bipolar ablations utilizing this novel strategy (Figure D top - unipolar, D bottom - bipolar). Following five bipolar RCFA lesions, the clinical VA was no longer inducible. The patient tolerated the procedure well with no further recurrence of VAs. Bipolar RFCA with a mapping catheter triangulating the target may help achieve deeper lesions.