Ablation of Ventricular Tachycardia Using the QDOT MICRO Ablation Catheter (VT-MICRO Study)

Catheter ablation is useful to treat patients with scar-related heart disease and ventricular tachycardia (VT). QDOT Micro catheter is a next generation catheter. Its optimized temperature control and micro-electrode technology are designed to provide more efficient and consistent lesion creation with an accurate myocardial substrate analysis. This study aims to compare the myocardial electro-anatomic maps obtained using QDOT and Pentaray (PR) catheters.

This study enrolled patients with symptomatic VT and indication to perform CA following the latest guidelines. Myocardial electro-anatomic maps were obtained using QDOT and Pentaray (PR) catheters. The primary objective was to assess the absence of sustained VTs or ICD interventions 12 months after the procedure.

Twelve patients were enrolled. The percentage of myocardial scar was higher using QDOTB map (15.5%) compared to PR (13.5%) and QDOTM-map (9%) (< 0.001). The percentage of myocardial borderzone was higher using QDOTB map (7.5%) compared to PR (6%) and QDOTM-map (3%) (p < 0.001). The average EGM amplitude acquired in the myocardial scar was higher in the QDOTM-map (0.24 mV) compared to PR (0.10 mV) and QDOTB-map (0.10 mV) (p < 0.001). The average EGM amplitude acquired in the myocardial borderzone was higher in the QDOTM-map (1.07 mV) compared to PR (0.80 mV) and QDOTB-map (0.72 mV) (p < 0.001). No sustained VT was documented at 12 month FU. No adverse events were documented.

Microelectrode mapping allows detection of higher voltage electrograms compared to standard bipolar mapping and PR mapping. In our small population, the HPSD protocol was used inside the low voltage areas without acute procedural complications.