AIMS:The primary goal of atrial fibrillation (AF) ablation is to improve AF-related symptoms and quality of life. Previous studies have observed a discrepancy between objective recurrence of AF after ablation and patient-perceived change of symptoms. Although predictors of freedom of AF recurrence after AF ablation have been widely studied, factors associated with symptom relief and quality of life improvement remain underexplored. The present study aimed to investigate determinants of symptom reduction and improvement in quality of life after AF ablation. METHODS AND RESULTS:A total of 382 AF patients (68% paroxysmal AF, 67% male, mean age 63 ± 9 years) undergoing AF ablation were included. Patient-reported outcomes were assessed using the Toronto Atrial Fibrillation Severity Scale (AFSS) and 36-Item Short-Form Health Survey (SF-36) score. Patients completed both the AFSS and SF-36 score pre-ablation, and post-ablation at 4 months and 1 year follow-up. Atrial tachyarrhythmia recurrence was documented in 139 patients (36%) at 1 year follow-up. AF symptom severity, patient-perceived AF burden and quality of life improved from baseline to 1 year follow-up, particularly in patients without atrial tachyarrhythmia recurrence. Greater baseline AFSS-derived symptom severity and patient-perceived AF burden were associated with a greater improvement of AF symptom severity and patient-perceived AF burden after ablation. CONCLUSION:This study shows that patients with lower quality of life and greater AF symptom severity and patient-perceived AF burden benefit most from AF ablation, suggesting that more emphasis should be put on the burden of AF symptoms in clinical decision-making.

INTRODUCTION:Accurate identification of arrhythmogenic substrate is essential for successful ventricular tachycardia (VT) ablation, yet existing electrogram-based methods are limited by far-field interference and operator dependence. Dominant frequency (DF) mapping offers a stimulus-independent alternative, but existing implementations lack anatomically integrated workflows with quantitative assessment of spatial concordance. METHODS:The objective of this study is to develop and evaluate a computational workflow for DF mapping with three-dimensional anatomical integration in patients undergoing substrate-guided VT ablation. We retrospectively analyzed 12 patients (mean age 57.5 ± 18.0 years; 75% male) with ischemic or non-ischemic cardiomyopathy. Intracardiac electrograms from SmartTouch or Pentaray catheters were segmented, transformed into the frequency domain, and thresholded using case-specific histograms. DF activity was projected onto patient-specific ventricular meshes, and spatial correspondence with operator-defined ablation sites was quantified using continuous proximity metrics (soft recall, soft precision) and receiver operating characteristic (ROC) analysis. RESULTS:DF analysis was successful in all cases, with projection errors < 4 mm. DF activity showed high soft recall (0.776-0.999) and variable soft precision (0.025-0.754). ROC AUC values ranged from 0.622 to 0.953, exceeding baseline in all cases. SmartTouch data generally yielded higher recall and greater separation between ablation and non-ablation points. CONCLUSION:DF mapping with anatomical integration is feasible across catheter types and demonstrates consistent spatial concordance with operator-defined VT ablation targets. This stimulus-independent workflow can be applied to routine mapping data and provides a framework for quantitative assessment of spatial relationships with procedural targets. DF values were case-specific and not comparable across patients, catheter types, or institutions. Prospective evaluation in larger cohorts is warranted.

Background:Pulmonary vein (PV) isolation can be performed using various ablation strategies, including point-by-point radiofrequency (RF) and single-shot ablation techniques. However, the resulting lesion characteristics of these approaches are not yet fully understood. Late gadolinium enhancement cardiac magnetic resonance (LGE-CMR) provides a noninvasive means to assess atrial ablation lesions. Objective:This study aimed to characterize ablation modality-specific left atrial LGE-CMR lesion patterns. Methods:Ablation lesion patterns of 42 patients were evaluated on LGE-CMR acquired 3 months after PV isolation was performed with point-by-point moderate-power moderate-duration RF, very-high-power short-duration RF, RF balloon, ultralow-temperature cryoablation, or pulsed field ablation (PFA). Left atrial LGE images were visually assessed and also postprocessed using the full-width half-maximum method for lesion quantification, with gap detection defined by a ≥40% threshold to assess lesion completeness. Results:Point-by-point RF ablation produced the most continuous LGE lesion patterns, whereas single-shot thermal techniques created broader but less continuous ablation lesions. PFA generated the widest and most heterogeneous patterns, with quantitative analysis confirming a high prevalence and large gap lengths in single-shot ablation groups, most prominently in the PFA group (total LGE encirclement: moderate-power moderate-duration 77.2% ± 10.1%; very-high-power short-duration 82.8% ± 12.4%; RF balloon 76.2% ± 11.6%; ultralow-temperature cryoablation 62.0% ± 9.9%; and PFA 60.2% ± 13.7%). Conclusion:LGE-CMR reveals modality-specific lesion patterns, with point-by-point RF showing the most continuous PV encirclement. PFA demonstrated variable lesion visualization, likely influenced by system differences and challenges in detecting nonthermal injury. The relationship between CMR-defined lesions and outcomes remains uncertain, underscoring the need for standardized imaging with emerging energy sources.

BACKGROUND:Interventional cardiac magnetic resonance imaging (iCMR) enables catheter ablation without ionizing radiation and provides real-time soft-tissue visualization. Recent developments have enabled initial clinical applications, with typical atrial flutter ablation serving as a benchmark to evaluate feasibility. OBJECTIVE:Describe procedural feasibility, efficiency, and clinical outcomes of iCMR-guided cavotricuspid isthmus (CTI) ablation in a single-center cohort. METHODS:We retrospectively analyzed 35 consecutive patients who underwent real-time iCMR-guided CTI ablation between September 2022 and February 2025. Procedures were performed on a 1.5T MR imaging scanner using active catheter imaging (ACI, n = 15) or active catheter tracking (ACT, n = 20). Procedural characteristics, technical performance, acute success, complications, and 1-year arrhythmia recurrence were evaluated. RESULTS:Mean age was 66 ± 7 years, and 9% were women. Acute bidirectional CTI block could be confirmed in 32 of 35 patients (91%). Median (interquartile range [IQR]) procedure duration was 106 (IQR, 70-128) minutes with ACI and 133 (IQR, 94-161) minutes with ACT (P = .07). Procedural or technical challenges occurred in 19 patients (54%), most commonly related to coronary sinus catheter positioning and workflow or system-integration issues. No major complications occurred. During 1-year follow-up, typical atrial flutter recurred in 6 of 32 patients (19%) with confirmed CTI block, with no difference between ACI (4 of 15 patients) and ACT (2 of 17 patients) (log-rank P = .29). CONCLUSION:iCMR-guided CTI ablation was feasible and could be performed safely using both ACI and ACT. However, procedural complexity, prolonged procedure times, and recurrence rates reflect the early implementation phase of this first-generation iCMR platform. Ongoing advances in catheter technology, system integration, and workflow optimization are expected to further improve procedural performance and support broader clinical adoption.

BACKGROUND AND AIMS:In 15-40% of patients undergoing repeat ablation for AF recurrence, all pulmonary veins (PVs) are durably isolated. Currently, there is limited evidence on the appropriate treatment strategy for these patients. We aimed to characterize and compare the effectiveness of different re-ablation strategies. METHODS:All patients referred for repeat AF ablation with all PVs durably isolated at 8 hospitals in the Netherlands were included [Netherlands-Heart-Registration (NHR); 2016-2019]. NHR data were were used to determine the presence of PV-reconnection, the ablation strategy used, and the outcome of ablation (atrial arrhythmia recurrence > 30 sec.). The effectiveness of ablation strategies was assessed with multivariable Cox models. RESULTS:Of 2311 repeat AF ablations performed, 274 (11.9%) patients had all PVs durably isolated. Median age was 66 (IQR:58-70) years, 44.2% women, 45.6% had persistent/long-standing-persistent AF. In 33 (12.0%) patients, no ablation was performed. A single ablation strategy was performed most often (41.2%). Posterior wall ablation (58.4%) was performed most often, followed by PV-antralization (26.3%). Over 2.0 (1.0-3.3) years, 147 (59.8%) patients had an atrial arrhythmia recurrence, and 30 (12.7%) patients had another repeat AF ablation within 1 year. After multivariable adjustment, no difference in atrial-arrhythmia recurrences was detected between individual ablation strategies, number of strategies performed, and type of atrial-arrhythmia (p > 0.05 for all). Left-atrial-volume-index was associated with a higher recurrence-risk [aHR 1.03(95%CI 1.01-1.05)]. CONCLUSION:In patients with durably isolated PVs, a high proportion experienced recurrence of atrial arrhythmias, with no difference in recurrence rates between different re-ablation strategies.

Background Esophageal injury is a recognized complication of radiofrequency (RF) pulmonary vein isolation (PVI). Very high-power, short-duration (vHPSD) ablation creates shallower lesions, potentially limiting esophageal damage. Objective This study evaluated esophageal injury using 3D LGE-CMR post-PVI in AF patients undergoing conventional or vHPSD RF ablation. Methods Patients with AF (n=59, 61±8yr) underwent primo RF PVI with ablation index (AI)-guided (30/40W,n=19) or vHPSD (90W/4s,n=40) ablation. 3D LGE-CMR was performed at baseline, <72h, and 3 months post-PVI. Esophageal signal intensity (SI) was measured in anterior and posterior wall at the mid–LA level in sagittal and axial planes, normalized to a reference to calculate SI ratio (SIRESO). Esophageal LGE was analyzed over time, by ablation type, esophageal position, and, in vHPSD, by posterior wall reconnection requiring touch-up ablation. Results Anterior SIRESO​ increased significantly <72 hours post-PVI and, although partially reduced at 3 months, remained above baseline (1.06[0.95–1.18] to 1.36[1.13–1.57] to 1.21[1.03–1.40], all p<0.01). Patients with the esophagus adjacent to a PV (n=48) had higher anterior SIRESO at both early and 3-month follow-up than those with inter-PV position (n=11). Partial SIRESO reduction at 3 months did not occur in the AI group. Within the vHPSD group (n=40), posterior touch-up ablation (n=13) was associated with persistently higher anterior SIRESO at 3 months. Posterior SIRESO remained unchanged over time. Conclusion RF PVI increased esophageal LGE early post-ablation, persisting at 3 months. Partial resolution occurred with vHPSD, but LGE remained elevated in both ablation types, especially when the esophagus was adjacent to a PV or after acute posterior wall reconnection requiring touch-up ablation.

BACKGROUND:Atrial fibrillation (AF) ablation may induce reverse left atrial (LA) remodeling, yet few studies have prospectively evaluated its short- and long-term effects. This study assessed LA volumetric and functional remodeling using cardiovascular magnetic resonance (CMR) imaging early and late after pulmonary vein isolation (PVI) in AF patients. METHODS:This study involved 61 AF patients undergoing radiofrequency PVI. CMR scans were performed pre-PVI, within 72 h and 3months post-PVI. LA volumes and strain were assessed using two- and four-chamber cine images. Early AF recurrence was monitored during 3months follow-up. RESULTS:LAVImin significantly increased early post-PVI (22.5±8.7 mL/m² to 25.8±9.9 mL/m², p<0.01). At 3months, both LAVImin and LAVImax significantly reduced compared to early post-PVI (25.4±8.87 mL/m2 to 19.4±7.7 mL/m2, p<0.001; 48.2±12.7 mL/m2 to 38.7±10.6 mL/m2, p<0.001, respectively), as well as compared to baseline (22.5±8.7 mL/m2 to 20.1±8.5 mL/m2, p=0.04; 45.6±11.8 mL/m2 to 39.3±11.2 mL/m2, p<0.001, respectively). Early post-PVI, LA emptying fraction (LA EF), LA reservoir, and contractile strain significantly reduced compared to baseline (from 51.6±10.8% to 47.1±8.9%, p<0.01; 18.3±4.4% to 15.4±2.9%, p<0.001; 8.3±3.1% to 5.4±1.8%, p<0.001, respectively). At 3months, LA EF, LA reservoir, and contractile strain significantly increased as compared to early post-PVI (from 47.1±8.9% to 50.5±8.6%, p<0.01; 15.4±2.9% to 16.8±3.1%, p<0.01; 5.4±1.8% to 6.9±2.3%, p<0.001, respectively). However, LA reservoir and contractile strain remained significantly lower compared to baseline (18.3±4.4% to 16.8±3.1%, p=0.02; 8.3±3.1% to 6.9±2.3%, p<0.01, respectively). In patients with early AF recurrence 27.9% (17/61), LA volume reduction and partial functional recovery were not observed during 3months post-PVI. CONCLUSION:LA volumes significantly reduced 3months post-PVI. While LA function initially declined, it showed partial recovery at 3months. However, LA reservoir and contractile strain remained reduced compared to pre-PVI. LA reverse remodeling and partial LA functional recovery only occurred in patients without early AF recurrence.

BACKGROUND:Late gadolinium enhancement (LGE) images, reconstructed using magnitude (MAG) or phase-sensitive inversion recovery (PSIR) sequences, differ in signal intensities because of their handling of longitudinal magnetization. These differences influence LGE quantification, which typically uses full-width at half maximum (FWHM) or standard deviation (n-SD) thresholding when predicting cardiac events. OBJECTIVE:This study assessed the impact of FWHM and n-SD on MAG- and PSIR-derived scar characteristics. METHODS:Patients with ischemic cardiomyopathy undergoing LGE imaging were retrospectively studied. Two reconstruction techniques (MAG vs PSIR) and 2 thresholding methods (FWHM vs n-SD) were evaluated. LGE images were postprocessed with commercially available software, using scar thresholds of 40%-60% of the maximum signal intensity for FWHM and 2-5 SDs above the mean for n-SD. Scar quantification was compared between patients with primary and secondary prevention implantable cardioverter-defibrillator. RESULTS:Of the 80 patients, 32 (40%) had an implantable cardioverter-defibrillator for primary prevention. PSIR imaging showed significantly larger scar metrics than did MAG using FWHM and n-SD thresholding, including larger border zone (16.43 ± 8.15 g vs 21.42 ± 10.72 g; P<.001) and conduction corridor (CC) characteristics. MAG-based analysis revealed significant differences in scar and CC metrics. For PSIR, scar metrics were consistent across FWHM and n-SD. MAG-based analysis showed larger border zone and CC length in patients with primary prevention, with similar trends for PSIR. CONCLUSION:This study demonstrates significant differences in myocardial scar metrics based on reconstruction and thresholding techniques. PSIR consistently provided robust scar characterization across methods, emphasizing its clinical potential to standardize LGE-cardiac magnetic resonance workflows and improve ventricular arrhythmia risk stratification.

Interventional cardiac magnetic resonance imaging (iCMR) offers distinct advantages for guiding complex cardiac procedures, including 3D visualization, soft tissue characterization, and avoidance of ionizing radiation. Transseptal puncture (TSP), essential for left heart access, poses specific challenges under MR-guidance. The development of MR-compatible TSP sets comprising non-ferromagnetic sheaths, dilators, and needles, represents a major step toward safe execution of TSP in the MRI environment. This report provides practical, step-by-step guidance for MR-guided TSP, focusing on imaging strategies and integration of advanced 2D and 3D navigation tools. Real-time cine imaging in dedicated planes enables precise localization of the fossa ovalis, confirmation of septal tenting, and avoidance of adjacent structures. Complementary use of a vendor-neutral MR-compatible 3D navigation system allows dynamic catheter tracking within a segmented static 3D anatomical shell, enhancing spatial orientation and procedural accuracy. Feasibility was demonstrated in a porcine model, where an MR-compatible sheath and trackable dilator were successfully navigated to the interatrial septum and TSP was achieved, enabling left atrial (LA) access. Subsequent mapping confirmed catheter positioning within the LA. Remaining challenges include limited guidewire visibility, low image temporal resolution compared with fluoroscopy, and the investigational status of current MR-compatible TSP sets. These factors must be addressed before clinical translation. In conclusion, MR-guided TSP using dedicated imaging planes and MR-compatible devices is technically feasible and may facilitate future radiation-free left heart interventions. Continued device refinement, including improved passive instrument visibility and active tracking technologies, faster real-time cine imaging, and regulatory approval are critical for safe and widespread clinical adoption.

Background Successful pulmonary vein isolation (PVI) promotes left atrial (LA) reverse remodeling, but its effect on right atrial (RA) remodeling remains unclear. Objective The purpose of this study was to assess the impact of radiofrequency (RF) PVI on RA volumes and function in patients with atrial fibrillation by using cardiac magnetic resonance imaging. Methods Forty-three patients with atrial fibrillation (32 (74.4%) males; mean age 61±7 years) undergoing first RF PVI, without atrial flutter ablation, underwent 3 cardiac magnetic resonance scans: pre-PVI, early (<72 hours) post-PVI, and 3 months post-PVI. Indexed atrial volumes (RA maximal/minimal volume index and LA maximal/minimal volume index) and function were derived from 2- and 4-chamber cine images, with longitudinal atrial strain analyzed using feature tracking. Results Early post-PVI, RA minimal volume index significantly decreased (from 28.7±10.3 to 26.0±9.9 mL/m2; P=.03) while RA emptying fraction significantly increased (from 37.3%±11.5% to 41.7%±10.1%; P=.03). At 3 months, both RA minimal volume index and RA maximal volume index showed further significant reductions compared with baseline (from 28.7±10.3 to 24.8±8.8 mL/m2; P=.002 and from 45.2±11.8 to 40.3±11.9 mL/m2; P<.001, respectively). During this period, RA functional improvement persisted, as evidenced by RA reservoir and contractile strain (from 16.2%±4.1% to 18.9%±3.6%; P=.003 and from 6.6%±2.6% to 8.3%±2.8%; P=.005, respectively). LA volumes remained unchanged early post-PVI, but at 3 months, LA maximal volume index significantly decreased compared with baseline (from 46.1±13.0 to 39.1±11.3 mL/m2; P<.001). LA function, demonstrated by reservoir and contractile strain, was significantly diminished early post-PVI, which persisted at 3 months compared with baseline (from 18.6%±4.0% to 17.0%±3.4%; P=.04 and from 8.5%±3.0% to 6.9%±2.4%; P<.01, respectively). Conclusion This study demonstrates that RF PVI results in reverse biatrial remodeling, with significant reductions observed in RA and LA volumes. RA function showed a significant improvement post-PVI, while LA function demonstrated persistent impairment at 3 months, possibly because of LA ablation scarring.

Implantable cardioverter-defibrillators (ICDs) play a vital role in the management of ventricular arrhythmias (VAs). To improve arrhythmia risk-stratification, late gadolinium enhancement (LGE) imaging can be used to identify and characterize the underlying arrhythmogenic substrate. This study aims to evaluate the relationship between LGE-derived quantitative scar metrics and appropriate ICD therapy. Patients with ischemic cardiomyopathy who underwent LGE imaging prior to ICD implantation between 2017 and 2019 were retrospectively identified. Scar characteristics were quantified using ADAS LV (ADAS LV Medical, Barcelona, Spain). Additional interface metrics were obtained using customized scripts. Magnitude (MAG) images were analysed and, when available, compared with phase-sensitive inversion recovery (PSIR) images to assess differences in scar quantification. Follow-up data was analysed to identify patients that received appropriate ICD therapy. A total of 90 patients were included. Over a median follow-up period of 63 months (IQR: 48-74 months), 28 (31%) received appropriate ICD therapy. MAG analysis revealed significant differences in core scar (8.37±5.96g vs. 17.1±7.61g, p<0.001), border zone (BZ) (10.18±5.78g vs. 19.03±6.77g, p<0.001), conduction corridor (CC) mass (3.03±3.11g vs. 6.95±3.66g, p<0.001), CC number (3.85±3.28 vs. 5.82±3.16, p=0.005), CC length (146.19±150.05mm vs. 271.36±138.85mm, p<0.001) and CC protectedness (71.5±89.83mm vs. 120.66±89.14mm, p<0.001) between patients with and without appropriate therapy. Furthermore, the interface between healthy myocardium and scar (70.64±39.77cm2 vs. 121.00±40.23cm2, p<0.001), as well as the interface between BZ and scar (61.61±35.07cm2 vs. 116.12±37.62cm2, p<0.001) was significantly larger in patients with appropriate ICD therapy. Additionally, with 80 cases available for comparison, significant differences were observed between MAG and PSIR analyses. PSIR showed larger core (11.15±7.75g vs. 18.83±11.37g, p<0.001), BZ (12.57±6.85g vs 23.12±12.85g, p<0.001), CC mass (4.16 ± 3.80g vs. PSIR: 5.58 ± 4.91g, p=0.038) and CC length (186.08 ± 160.31mm vs. 226.85 ± 169.23mm, p=0.041), although the total CC number (p=0.26) and CC protectedness did not differ significantly between the two reconstruction methods (p=0.079). Moreover, the interface between healthy myocardium and scar (84.30±45.56 cm2 vs. 112.47±60.50cm2, p<0.001) and the interface between BZ and scar (89.36±95.87cm2 vs. 100.17±87.19cm2, p<0.001) were significantly different for MAG and PSIR. LGE-derived quantitative scar metrics are predictors of appropriate ICD therapy in patients with ischemic cardiomyopathy. The differences observed between PSIR and MAG suggest that PSIR may offer more detailed and accurate scar quantification, potentially improving risk assessment for ICD therapy.Figure 1 Figure 2

Pulmonary vein isolation (PVI) using radiofrequency (RF) ablation is an established treatment for atrial fibrillation (AF). While a successful PVI in AF patients is known to promote reverse left atrial (LA) remodeling, the impact of PVI on right atrial (RA) remodeling remains poorly understood. To assess RA volumetric and functional remodeling parameters using cardiac magnetic resonance (CMR) imaging early (<72h) and late (3 months) after PVI. Forty-three AF patients (74.4% male, 61±7 years) who underwent primo radiofrequency (RF) PVI, without prior or additional atrial flutter ablation, underwent three CMR scans: pre-PVI, early (<72 hours), and 3 months post-PVI. Atrial volumes and function were assessed using two- and four-chamber cine images, with atrial volumes indexed to body surface area (RAVImin, RAVImax, LAVImin, and LAVImax). Longitudinal atrial strain (reservoir, conduit, and contractile function) was analyzed using feature tracking (Circle CVI42). Early (<72h) post-PVI, RAVImin significantly decreased from 28.7 ± 10.3mL/m² to 26.0 ± 9.9mL/m² (p = 0.03), while RA EF demonstrated a significant increase (37.3 ± 11.5% to 41.7 ± 10.1%, p=0.03). At 3 months, both RAVImin and RAVImax showed significant further reductions compared to baseline (28.7 ± 10.3mL/m² to 24.8 ± 8.8mL/m², p=0.002; 45.2 ± 11.8mL/m² to 40.3 ± 11.9mL/m², p<0.001, respectively). During this period, RA functional improvement persisted, as evidenced by RA reservoir strain and RA contractile strain (16.2 ± 4.1% to 18.9 ± 3.6%, p=0.003; 6.6 ± 2.6% to 8.3 ± 2.8%, p=0.005, respectively) (Figure 1). LA volumes remained unchanged early post-PVI, but at 3 months, LAVImax significantly decreased compared to baseline (46.1 ± 13.0mL/m2 to 39.1 ± 11.3mL/m2, p<0.001). LA function, as assessed by reservoir and contractile strain, was significantly diminished early post-PVI (Table 1), and this reduction persisted at 3 months compared with baseline (18.6 ± 4.0% to 17.0 ± 3.4%, p=0.04; 8.5 ± 3.0% to 6.9 ± 2.4%, p<0.01, respectively). This study demonstrates that RF PVI promotes reverse bi-atrial remodeling, with significant reductions observed in both RA and LA volumes, most likely due to reduced AF burden. LA function demonstrated a persistent impaired function at 3 months, while RA function improved following PVI. These findings suggest that although the reduction in AF burden may improve RA function and reduce atrial volumes, ablation-induced injury may contribute to a persistently reduced LA function.RA remodeling post-PVI RA and LA remodeling post-PVI

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.

Cardiac implantable electronic devices (CIEDs) can cause significant artifacts in late gadolinium enhancement (LGE) cardiac magnetic resonance imaging (CMR), compromising image quality and diagnostic accuracy. Currently, no consensus exists on optimal patient selection for LGE-CMR in this context. This study aims to identify predictors of LGE image quality in patients with CIEDs to improve patient-selection for LGE-CMR. Patients with CIED who underwent conventional, 2-dimensional LGE imaging were retrospectively identified from the AmsterdamUMC CMR database. Baseline clinical characteristics and device specifications were collected, and distance measurements were performed on post-device implantation chest X-ray (Antero-Posterior view), i.e. shortest distance generator to RV lead tip. LGE image quality was categorized as fully diagnostic, moderate, or poor by two independent, experienced CMR readers. Predictors of image quality were then analyzed using clinical and chest X-ray parameters. 75 patients were included in this study (mean age 62 ± 13 years, 70.7% male). The diagnostic quality of CMR scans was as follows: 35 (47%) scans were fully diagnostic, 22 (29%) were moderate (5±1 non-diagnostic segments), and 18 (24%) were poor (11±3 non-diagnostic segments). A Chi-Square test revealed a significant association between device type and image quality (χ²=27.36, p<0.001). Adjusted residual analysis showed that implantable cardioverter defibrillators (ICDs) were significantly associated with poor image quality (+2.4, p < 0.05), while pacemakers (PMs) were associated with good image quality (+4.7, p < 0.05). Ordinal regression analysis confirmed that the distance from the generator to RV lead tip was a significant predictor of LGE image quality (p=0.013). ROC analysis identified an optimal threshold of 94.45 mm for the generator-to-RV lead tip distance to maintain diagnostic image quality. Both device type and spatial positioning significantly impact image quality. Specifically, ICDs were associated with poorer image quality, while PMs generally yielded diagnostic-quality images. The distance from the device generator to the RV lead tip emerged as a critical predictor, with specific thresholds that may guide clinical choices about which CIED patients are suitable for LGE-CMR. These findings suggest that considering device type and positioning may help identify which patients are suitable for CMR and improve diagnostic accuracy in this population.Figure 1

Background Advanced postprocessing of late gadolinium enhancement cardiac magnetic resonance (CMR) and computed tomography (CCT) imaging increasingly guides ventricular tachycardia ablation. However, a direct comparison between 2 widely adopted platforms, ADAS 3D LV (Adas3D Medical) and inHEART (IHU Liryc/Inria), is lacking. Objective This study aimed to compare CMR- and CCT-derived ventricular substrate models generated by ADAS 3D and inHEART in patients with ischemic and nonischemic cardiomyopathy undergoing ventricular tachycardia ablation. Methods Patients who underwent both CCT and late gadolinium enhancement CMR before ablation were retrospectively included. ADAS 3D models were generated on-site, whereas inHEART models were processed remotely. Substrate models were evaluated using a custom scoring system incorporating quantitative (scar mass, transmurality) and qualitative parameters (wall thickness, scar delineation, and conduction corridors). Electroanatomic maps (EAMs) assessed correspondence between low-voltage and ablation regions, with imaging-defined corridors. Results 16 patients (n = 8 ischemic, n = 8 nonischemic) were analyzed; 12 had detailed EAM data. Scar core and border zone measurements were comparable between platforms in both subgroups (all P > .05). ADAS 3D showed slightly higher visualization scores, particularly in nonischemic cardiomyopathy, although differences were not statistically significant. Spatial concordance between imaging-derived scar and EAM-defined ablation areas was good to excellent in 10 of 12 cases. Conclusion ADAS 3D and inHEART demonstrated high concordance in scar quantification and substrate characterization, with comparable performance across cardiomyopathy types. Given their complementary strengths, platform choice should be guided by procedural goals, imaging availability, operator experience, and institutional context, as each system offers distinct advantages. Prospective studies are needed to evaluate the impact on procedural success and long-term outcomes.

BACKGROUND:Implantable cardioverter defibrillator (ICD) therapy can prevent sudden cardiac death, but poses a risk of inappropriate device therapy (IDT), which is linked to worse outcomes and reduced quality of life. On the other hand, ICDs can function as an early warning system for atrial arrhythmias. PURPOSE:This study aimed to predict which patients are at risk of IDT and who develop atrial high-rate episodes (AHRE) by investigating pre-implant clinical parameters. METHODS:Patients who received an ICD with an atrial lead between 2010 and 2019 were included in a prospective registry. RESULTS:Over 5.3 ± 3.0 years, 136 of 413 patients received appropriate device therapy, and 36 patients received IDT. Univariate cox regression analyses on 40 parameters were performed, followed by forward multivariate cox regression. The best predictive model (Harrell's C-index 0.785) included secondary prevention ICD, ischemic CMP (iCMP), CMP not classified as ischemic, hypertrophic or dilated (uCMP), and diuretic use as risk factors, with mineralocorticoid receptor-antagonists (MRA) use and diabetes as protective factors. Surprisingly, AF was not a predictor of IDT. Among 313 patients without prior AF, 136 developed AHRE. Similar cox regressions predicted AHRE development, resulting in a model (Harrell's C-index 0.663) based on age, left ventricular ejection fraction (LVEF), hypertrophic CMP (hCMP), family history of cardiovascular disease (CVD), and hypercholesterolemia. CONCLUSION:This study identified six factors that influence the risk of IDT, and five other factors as risk factors for developing AHRE. Pre-implant assessment of these variables can help to better inform patients of the potential benefits and risks.

Background: Cardiac implantable electronic devices (CIEDs) can cause artifacts in late gadolinium enhancement (LGE) cardiac magnetic resonance imaging (CMR), compromising diagnostic accuracy. No consensus exists on optimal CIED patient selection for LGE-CMR. Objective: This study aims to identify predictors of LGE image quality in patients with CIEDS to optimize pre-scan selection. Methods: Patients with CIEDs who underwent conventional 2D-LGE imaging were retrospectively identified from the Amsterdam UMC CMR database. Baseline clinical and device characteristics were collected, and generator-to-lead distance was measured on post-implantation chest X-rays. LGE quality was categorized as fully diagnostic, acceptable, or non-diagnostic. Multivariable regression and receiver operating characteristic (ROC) analysis determined independent predictors and exploratory generator-to-lead distance thresholds using a 90% sensitivity criterion. Results: Overall, 80 patients (71.3% male, mean age 64 years) were included: 41.3% ICDs, 23.8% pacemakers (PMs), 23.8% cardiac resynchronization therapy defibrillators (CRT-Ds), and 2.5% cardiac resynchronization therapy pacemakers (CRT-Ps). LGE image quality was fully diagnostic in 48.8%, acceptable in 27.5%, and non-diagnostic in 23.8% of patients. PM/CRT-P patients had no non-diagnostic scans (92.9% fully diagnostic). Only 25.0% of ICD/CRT-D scans were fully diagnostic, while 36.5% were non-diagnostic (P < .001). Generator-to-lead distance was significantly associated with LGE quality, with thresholds of 10 cm in ICDs and 8 cm in PMs for acceptable LGE quality. Conclusion: Device type and positioning significantly impact LGE image quality. ICDs were associated with poorer image quality, while PMs consistently yielded diagnostic-quality images. Generator-to-lead distance emerged as a key predictor, providing a practical tool for optimizing LGE-CMR referrals. This study defines generator-to-lead distance thresholds by device type and proposes a structured pre-scan workflow to support LGE-CMR referral decisions in patients with CIEDs.

Pulmonary vein isolation (PVI) using radiofrequency (RF) ablation is an established treatment for atrial fibrillation (AF). Although successful restoration of sinus rhythm after PVI is known to ultimately result in left atrial (LA) reverse remodeling, little is known about the impact of PVI on the dynamic progression of LA volumes and function during the blanking period, especially in the context of early AF recurrence. To assess LA volumetric and functional remodeling parameters using CMR early (<72h) and later (3 months) after PVI in patients with and without early AF recurrence. This study involved 44 patients (61±8 years, 72.7% male, 68.2% paroxysmal AF) undergoing RF pulmonary vein isolation (PVI). CMR scans were performed before the PVI procedure, <72 hours post-PVI, and repeated 3 months post-PVI. LA volumes and strain were assessed using two- and four-chamber cine images (Circle CVI, Calgary, Canada). Minimum and maximum LA volumes were indexed to body surface area to compute LAVImin and LAVImax, respectively. Longitudinal LA strain was analyzed through the feature tracking model, subdivided into reservoir, conduit, and contractile strain. AF, atrial flutter, or atrial tachycardia episodes, detected either through 24h Holter monitoring and ECG or Kardia recordings, were considered early AF recurrence during the blanking period of 90 days post-ablation. LA volumes significantly decreased at 3 months post-PVI (Figure 1). Early post-PVI, LA function, as measured by LA emptying fraction (LA EF), LA reservoir, and LA contractile strain, showed significant reductions (52.5±11.1% to 48.1±7.9%, p=0.02; 18.1±4.5% to 15.2±2.4%, p<0.001; 8.3±3.1% to 5.3±1.7%, p<0.001, respectively). At 3 months, LA reservoir and contractile strain partially recovered, although LA contractile strain remained significantly lower than baseline (8.3±3.1% to 6.7±2.3%,p<0.01). Arrhythmia recurrence in the 90-days blanking period was observed in 13 of the 44 patient (29.5%). Notably, LAVImax reduced at 3 months in both groups, while LAVImin did not significantly decrease in the early AF recurrence group (Figure 2). Patients without early AF recurrence, exhibited improved LA function at 3 months as compared to early post-PVI, indicated by increased LA reservoir (15.3±2.5% to 17.1±3.1%, p=0.01) and LA contractile strain (5.3±1.8% to 6.7±2.4%, p<0.01), which was not observed in patients with early AF recurrence (Figure 2). LA volumes significantly reduced 3 months post-PVI, indicating reversed atrial remodeling. While LA function initially declined, it showed partial recovery at 3 months, as LA contractile strain did not recover to pre-PVI levels. LA reverse remodeling occurred in patients regardless of early AF recurrence, however, recovery of LA function was only observed in those without early AF recurrence.LA remodeling post-PVI LA remodeling in early AF recurrence