First-in-Human Real-Time MR-Guided Ventricular Ablation for Idiopathic Outflow Tract Premature Ventricular Complexes.

Importance Catheter ablation is a cornerstone therapy for symptomatic ventricular arrhythmias, yet current techniques rely on fluoroscopy and electroanatomic mapping, which provide limited soft-tissue detail and expose patients and staff to ionizing radiation. Real-time magnetic resonance (MR)-guided ablation may overcome these limitations by enabling direct visualization of cardiac anatomy, substrate, and lesion formation, all within a radiation-free environment. Objective To demonstrate the technical feasibility and safety of the first-in-human real-time MR-guided radiofrequency ventricular ablation procedure. Design, Setting, and Participant This was a prospective, worldwide-first roll-in case from the ongoing VISABL-VT nonrandomized clinical trial assessing MR-guided radiofrequency ablation of ventricular tachycardia. The procedure and analysis were performed in April 2025 at an academic tertiary care center equipped with a standard 1.5-T MR imaging (MRI) suite and dedicated MR-compatible electrophysiology platform, MR-compatible 12-lead electrocardiographic monitoring and recording system, MR-conditional defibrillator, and real-time catheter tracking integrated with the MRI scanner for synchronized imaging and ablation. The patient was a 73-year-old man with symptomatic, drug-refractory outflow tract premature ventricular complexes (PVCs). Intervention The ablation was performed under general anesthesia inside the MRI scanner. Intraprocedurally acquired noncontrast 3-dimensional MR angiographic imaging was used to create an anatomical roadmap for the procedure. Real-time catheter tracking and activation mapping were performed using actively tracked diagnostic and ablation catheters. Mapping identified earliest activation first in the posterior septal right ventricular outflow tract, where ablation transiently suppressed PVCs. Ectopy recurred but was ultimately resolved by ablation performed via a retrograde aortic approach in the left coronary cusp. Lesion formation was confirmed via postprocedural MRI. Main Outcomes and Measures Suppression of PVCs and presence or absence of procedural complications. Results The procedure was performed under real-time MRI guidance without complications. PVCs were completely suppressed, with no recurrence during 30-minute observation or at 2-month follow-up. Conclusions This first-in-human case demonstrates that ventricular ablation can be safely and effectively performed entirely under real-time MR guidance. Further evidence from the VISABL-VT trial will clarify clinical utility and long-term outcomes.