Cardiovascular Magnetic Resonance-Guided Radiofrequency Ablation

The possibilities of cardiovascular magnetic resonance (CMR) imaging for myocardial tissue characterization and catheter ablation guidance are accompanied by some fictional concepts. In this review, we present the available facts about CMRguided catheter ablation procedures as well as promising, however unproven, theoretical concepts. CMR promises to visualize the respective arrhythmogenic substrate and may thereby make it more localizable for electrophysiology (EP)based ablation. Robust CMR imaging is challenged by motion of the heart resulting from cardiac and respiratory cycles. In contrast to conventional passive tracking of the catheter tip by real-time CMR, novel approaches based on active tracking are performed by integrating microcoils into the catheter tip that send a receiver signal. Several experimental and clinical studies were already performed based on real-time CMR for catheter ablation of atrial and ventricular arrhythmias. Importantly, successful ablation of the cavotricuspid isthmus was already performed in patients with typical atrial flutter. However, a complete EP procedure with real-time CMR-guided transseptal puncture and subsequent pulmonary vein isolation has not been shown so far in patients with atrial fibrillation. Moreover, real-time CMR-guided EP for ventricular tachycardia ablation was only performed in animal models using a transseptal, retrograde, or epicardial access-but not in humans. Essential improvements within the next few years regarding basic technical requirements, such as higher spatial and temporal resolution of real-time CMR imaging as well as clinically approved cardiac magnetic resonance-conditional defibrillators, are ultimately required-but can also be expected-and will move this field forward. (J Am Coll Cardiol EP 2022;8:261-274) (c) 2022 by the American College of Cardiology Foundation.

Automated summary

Cardiovascular magnetic resonance (CMR) imaging offers potential for myocardial tissue characterization and catheter ablation guidance. Although some success has been achieved in experimental and clinical studies, there are still challenges and unproven theoretical concepts.