Ablation of left ventricle summit PVCs using guidewire and 2F octapolar microcatheter mapping

FUNDING ACKNOWLEDGEMENTS: Type of funding sources: None. BACKGROUND: Ventricular arrhythmias originating in the left ventricular summit region are especially difficult to map and ablate. The development of microcatheters allows access to the septal coronary venous system, which facilitates its mapping. PURPOSE: To describe the strategy for mapping and ablation of ventricular LV-Summit extrasystoles in the first 6 cases at our center, performed using a 2F octapolar microcatheter, as well as the results obtained. METHODS: 6 cases of left ventricular summit PVCs were recruited between January 2019 and October 2022. TTE and/or MRI were performed as well as initial Holter, evidencing a high density of PVCs. The studies were carried out with intracardiac echo and anatomical reconstruction with a navigator. The coronary sinus was cannulated with a 6F guide catheter for venography. Mapping of the septal coronary venous system was performed with a 4F vertebral catheter and angioplasty guidewire, connecting the guidewire to the polygraph where good precocity (up to -30 ms) was obtained with a QS pattern in the monopolar lead during PVCs. An octapolar catheter was advanced, obtaining maximum precocity and appreciating fragmented late potentials and local abnormal ventricular activities (LAVA) during sinus rhythm with greater precocity during extrasystole and achieving a topostimulation of 95% concordance with PVCs. Radiofrequency applications were made with an irrigated contact catheter in the areas facing the octapolar catheter until acute suppression of PVC was achieved and its absence was verified after infusion of isoprenaline. RESULTS: The mean age of the sample was 60 years, 3 of them women, with a mean LVEF of 51% and a daily average of PVCs of 17.28%. Three of the patients had previously studied cardiomyopathies. After ablation, antiarrhythmics were stopped in 80% of cases and beta-blockers in 40%. The percentage of PVCs was significantly reduced (mean after the procedure 4.4%, p = 0.04) with a single recurrence at follow-up. No complications were recorded. CONCLUSIONS: The microcatheter-guided ablation of the septal coronary venous system is a safe and effective procedure for the removal of left ventricular summit PVCs. [Figure: see text] [Figure: see text]