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Aims: This randomized single-centre study sought to compare the efficacy and safety of pulmonary vein isolation (PVI) plus voltage-guided ablation vs. PVI with or without linear ablation depending on the type of atrial fibrillation (AF).Methods and results: Overall, 124 ablation-naive patients with paroxysmal or persistent AF were randomized to PVI with (persistent AF) or without (paroxysmal AF) additional linear ablation (control group) vs. PVI plus ablation of low-voltage areas (LVAs) irrespective of AF type. Bipolar voltage mapping was performed during stable sinus rhythm. An LVA consisted of  ≥ 3 adjacent mapping points that each had a peak-to-peak amplitude ≤0.5 mV. After a mean follow-up of 12 ± 3 months, significantly more patients in the LVA ablation group were free from atrial arrhythmia recurrence >30 s off antiarrhythmic drugs (AADs) after a single procedure (primary endpoint) compared with control group patients [40/59 (68%) vs. 25/59 (42%), log-rank P = 0.003]. Arrhythmia-free survival on or off AADs was found in 33/59 control group patients (56%) and in 41/59 LVA ablation group patients (70%) (adjusted log-rank P = 0.10). During the 7 day Holter monitoring period at 12 months, significantly more patients in the LVA ablation group were free from arrhythmia recurrence on or off AADs [45/50 (90%) vs. 33/46 (72%), P = 0.04]. No between-group differences were observed regarding procedure duration, fluoroscopy time, and major complications.Conclusion: In this single-centre study, individually tailored substrate modification guided by voltage mapping was associated with a significantly higher arrhythmia-free survival rate compared with a conventional approach applying linear ablation according to AF type. [ABSTRACT FROM AUTHOR]

Aims To prospectively determine evaluability of routine cardiovascular magnetic resonance (CMR) diagnostic modules in a referral population of implanted rhythm device all-comers, and to establish a device-dependent CMR imaging strategy to achieve optimal image quality. Methods and results One hundred and twenty-eight patients with cardiac implantable electronic devices [insertable cardiac monitoring system, n  = 14; implantable loop-recorder, n  = 21; pacemaker, n  = 31; implantable cardioverter-defibrillator (ICD), n  = 50; and cardiac resynchronization therapy defibrillator (CRT-D), n  = 12] underwent clinically indicated CMR at 1.5 T. CMR protocols were tailored to the clinical indication and consisted of cine, perfusion, T1-/T2-weighted, late-gadolinium enhancement (LGE), 3D angiographic, and post-contrast cine spoiled gradient echo (SGE) scans. Image quality was determined using a 4-grade visual score per myocardial segment. Segmental evaluability was strongly influenced by device type and location with the highest proportion of non-diagnostic images encountered in the presence of ICD/CRT-D systems. Cine steady-state free-precession (SSFP) imaging was found to be mostly non-diagnostic in ICD/CRT-D patients, but a significant improvement of image quality was demonstrated when using SGE sequences with a further incremental improvement post-contrast resulting in an overall four-fold higher likelihood of achieving good image quality. LGE scans were found to be non-diagnostic in about one-third of left-ventricular segments of ICD/CRT-D patients but were artefact-free in > 94% for all other device types. Conclusion Device type and location constitute the main independent predictors of CMR image quality and thus, need to be considered during protocol adaptation. Most notably, post-contrast SGE cine imaging proved superior to conventionally used SSFP sequences. Thus, following the proposed device-dependent CMR imaging strategy, diagnostic image quality can be achieved in the majority of device patients. [ABSTRACT FROM AUTHOR]

Aims: Electrical cardioversion (ECV) is frequently required for early atrial fibrillation (AF) recurrence after catheter ablation. However, in some cases, ECV is unsuccessful, and factors associated with long-term rhythm outcomes after failed ECV are unknown. This study aimed to identify possible predictors of ECV failure early after AF ablation and to analyse management and long-term rhythm outcome of these patients.Methods and results: Between 2010 and 2012, 180 consecutive patients (mean age 63.7 ± 9.4 years, male 53.3%, persistent AF 60%) underwent successful radiofrequency AF ablation but required post-procedural ECV due to early AF recurrence (≤ 7 days). Of these, 120 patients were successful (Group A, n = 120, 66.7%) and 60 failed (Group B, n = 60, 33.3%). ECV failure was associated with diabetes [odds ratio (OR) 2.34, 95% confidence interval (CI) 1.154-4.763; P = 0.01] and lack of beta-blocker medication (OR 2.38, 95% CI 1.005-5.635; P = 0.04). In contrast, there were no significant differences in echocardiographic or procedure-related parameters. Atrial fibrillation recurrence was monitored with sequential 7 days of Holter electrocardiogram for 24 months (on average 10.8 ± 8.8 months) and was documented in 56%, n = 102 in total (Group A: 57%, n = 69 vs. Group B: 55%, n = 33; P = 0.75). Compared with successful ECV, ECV failure shortly after AF ablation had no predictive value on rhythm outcome in the long term (P = 0.98). The necessity of additional linear lesions during catheter ablation [hazard ratio (HR) 2.72, 95% CI 1.47-5.05; P = 0.001], AF duration (HR 1.08, 95% CI 1.04-1.12; P < 0.001), and a prolonged ablation time (HR 3.27, 95% CI 1.53-6.97; P = 0.002) were associated with long-term AF recurrence.Conclusion: Patients with diabetes and absence of beta-blocker medication are at higher risk for ECV failure. Early post-ablation ECV failure is not associated with long-term rhythm outcome. [ABSTRACT FROM AUTHOR]

Aims: This study aimed to assess the impact of supraventricular tachycardia (SVT) on long-term results of radiofrequency catheter ablation therapy of ventricular tachycardia (VT) in a large cohort of patients with arrhythmogenic right ventricular dysplasia/cardiomyopathy (ARVD/C).Methods and results: Supraventricular tachycardia occurrence has been studied in patients from our ARVD/C registry (70 patients, 48 male, age 53.2 ± 14.0, 45 patients (64.3%) with previous VT ablation). SVT were diagnosed in 26 of 70 patients (37.1%). Atrial fibrillation (AF) was the most frequent atrial arrhythmia, diagnosed in 17 patients (24.3%). In univariate analysis advanced age, clinical symptoms of heart failure, enlarged right atrium, diagnosis of significant tricuspid regurgitation (TR), and inappropriate implantable cardioverters-defibrillators therapy were associated with SVT. In binary logistic regression analysis only heart failure: hazard ratio (HR) 10.89, 95% confidence interval (95% CI) 1.08-109.96 (P = 0.043) and significant TR: HR 4.79, 95% CI 1.35-16.33 (P = 0.015) remained associated with SVT. In patients with previous VT ablation Cox multiple regression survival analysis revealed older age (≥53 years): HR 4.63, 95% CI 1.51-14.24 (P = 0.008) and SVT: HR 3.01, 95% CI 1.15-7.89 (P = 0.025) as predictors for VT recurrence during the follow-up.Conclusion: SVT and older age are associated with the recurrence of VT after catheter ablation in patients with ARVD/C. [ABSTRACT FROM AUTHOR]

Aims: Cardiac magnetic resonance (CMR) imaging in patients with implanted cardiac devices is often limited by device-related imaging artefacts. Limitations can potentially be overcome by employing a broadband late gadolinium enhancement (LGE)-CMR imaging technique. The purpose of this study was to investigate the relationship between implanted cardiac devices and the optimal frequency offset on broadband LGE-CMR imaging to increase the artefact-free visibility of myocardial segments.Methods and results: A phantom study was performed to characterize magnetic field disturbances related to 15 different cardiac devices. This was complemented by B0 and B1+ imaging of three different device types in four healthy volunteers. Findings were validated in 28 patients with an indication for arrhythmogenic substrate characterization before catheter ablation. In the phantom study, the placement of a PM, implantable cardioverter-defibrillator (ICD) or CRT-D generator led to a significant impairment of the radiofrequency field. B0 mapping in phantom and volunteers showed the highest off-resonance maximum with CRT-D systems with the maximum off-resonance significantly decreasing for ICD or PM systems, respectively. In all patients, with conventional LGE imaging 73.1% (61.5-92.3%) of LV segments were free of device-related artefacts, while with the broadband LGE technique, a significant increase of artefact-free segments was achieved [96.4% (85.7-100%); P = 0.00008].Conclusion: Using a modified broadband sequence for LGE imaging significantly increased the number of artefact-free myocardial segments thereby leading to improved diagnostic value of the CMR exam. Since the occurrence and extent of hyperintensity artefacts are closely related to the individual device, more studies are warranted to evaluate if the results can be extrapolated to other devices and manufacturers. [ABSTRACT FROM AUTHOR]

Aims: Supraventricular tachycardia, mistakenly diagnosed as ventricular tachycardia, may lead to inappropriate ICD therapy. Inappropriate ICD therapy associates with increased morbidity and mortality. A reduction of inappropriate therapy is therefore desired.Methods and Results: We present three different cases that beautifully illustrate the diagnostic possibilities of stored electrograms. Initial differential diagnoses in all three patients included ventricular tachycardia, focal atrial tachycardia, atrio-ventricular re-entry tachycardia, and atrio-ventricular nodal re-entry tachycardia. The first case was diagnosed as atrio-ventricular nodal re-entry tachycardia. In the second case, atrio-ventricular re-entry tachycardia was revealed. Ectopic atrial tachycardia was the reason for inappropriate therapy in the third patient.Conclusion: Thorough analysis of stored electrograms yielded correct diagnosis in all cases, which subsequently was confirmed by electrophysiological study. [ABSTRACT FROM AUTHOR]

Background: Epicardial radiofrequency catheter ablation is currently considered as the therapeutic option of choice in patients with arrhythmogenic right ventricular dysplasia/cardiomyopathy (ARVD/C) and recurrent ventricular tachycardia (VT). We hypothesised that inducibility of VT may guide the ablation strategy and thereby affect long-term results. Additional epicardial ablation was only performed if VT were still inducible after thorough endocardial ablation.Methods: The objective was to examine an inducibility-guided ablation approach by comparing the long-term results between endocardial and epi-endocardial radiofrequency catheter ablation of VT in a large cohort of patients with ARVD/C.Results: We studied from our ARVD/C registry (70 patients in total, 48 males, age 53.2 ± 14.0) 45 patients (64.3% of all patients) who underwent catheter ablation of VT. All patients received endocardial VT ablation. After endocardial ablation, 24 patients (53.3%) remained inducible. Additional epicardial ablation was performed in 22 patients (48.9%). After ablation, non-inducibility was achieved in overall 38 patients (84.4%). During a mean follow-up of 31.1 ± 27.4 months, 13 patients in each group (59.1% after endo- and epicardial ablation, 56.5% after endocardial ablation) remained free from VT recurrence (P = 0.862).Conclusions: An inducibility-guided catheter ablation strategy of VT in patients with ARVD/C prevents unnecessary epicardial ablation and may therefore be considered as an alternative to primary combined endo- and epicardial ablation. [ABSTRACT FROM AUTHOR]