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Background Fluoroscopy-guided catheter ablation has become the gold standard for treatment of cardiac arrhythmias. High resolution electro-anatomical mapping systems have become fundamental to perform these procedures. Recently, interventional cardiac magnetic resonance (iCMR) has been proposed as an alternative for fluoroscopy to guide atrial flutter ablations. The clinical experience with iCMR and dedicated three-dimensional mapping systems is growing. NorthStar is currently the first available vendor-neutral mapping system. Case summary We performed a real-time CMR-guided cavotricuspid isthmus (CTI) catheter ablation (CA) on a 69-year-old man using a novel mapping system (NorthStar Mapping System, Imricor Medical Systems, MN, USA). Starting from the CMR imaging, a pre-rendered segmentation model was loaded on NorthStar and used to guide the catheters, display voltage and activation maps, show mapping and ablation points. NorthStar can also take full control of the CMR scanner (i.e. start/stop sequences for anatomical information, tissue characterization, and catheter visualization) and communicate with the recorder/stimulator system (Advantage-MR EP, Imricor Medical Systems, MN, USA). With comparable procedural time to standard fluoroscopy-guided CA, CTI bidirectional block was achieved, without any complication. Discussion Using the NorthStar Mapping System, we managed to achieve a successful CMR-guided CTI ablation without any complication. Its further use should be explored, especially in more complex arrhythmias where a substrate-guided ablation is critical, as it could significantly improve results in terms of arrhythmia recurrence. [ABSTRACT FROM AUTHOR]

Background: Incomplete atrial lesions resulting in pulmonary vein‐left atrium reconnection after pulmonary vein antrum isolation (PVAI), are related to atrial fibrillation (AF) recurrence. Unfortunately, during the PVAI procedure, fluoroscopy and electroanatomic mapping cannot accurately determine the location and size of the ablation lesions in the atrial wall and this can result in incomplete PVAI lesions (PVAI‐L) after radiofrequency catheter ablation (RFCA). Aim: We seek to evaluate whether cardiac magnetic resonance (CMR), immediately after RFCA of AF, can identify PVAI‐L by characterizing the left atrial tissue. Methods: Ten patients (63.1 ± 5.7 years old, 80% male) receiving a RFCA for paroxysmal AF underwent a CMR before (<1 week) and after (<1 h) the PVAI. Two‐dimensional dark‐blood T2‐weighted short tau inversion recovery (DB‐STIR), Three‐dimensional inversion‐recovery prepared long inversion time (3D‐TWILITE) and three‐dimensional late gadolinium enhancement (3D‐LGE) images were performed to visualize PVAI‐L. Results: The PVAI‐L was visible in 10 patients (100%) using 3D‐TWILITE and 3D‐LGE. Conversely, On DB‐STIR, the ablation core of the PAVI‐L could not be identified because of a diffuse high signal of the atrial wall post‐PVAI. Microvascular obstruction was identified in 7 (70%) patients using 3D‐LGE. Conclusion: CMR can visualize PVAI‐L immediately after the RFCA of AF even without the use of contrast agents. Future studies are needed to understand if the use of CMR for PVAI‐L detection after RFCA can improve the results of ablation procedures. [ABSTRACT FROM AUTHOR]