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Introduction: The MARVEL study demonstrated at a single time point that accelerometer (ACC)‐based atrial sensing improves atrioventricular (AV) synchrony (AVS) in patients with AV block and a Micra pacemaker (Medtronic, Minneapolis, MN, USA). The purpose of the MARVEL Evolve substudy was to assess the performance over time. Methods: This prospective single‐center study compared AVS and ACC signals at two visits ≥6 months apart. Custom software was temporarily downloaded into the Micra at each visit and AVS was measured during 30 min at rest. Results: Nine patients from the MARVEL study were enrolled. The mean (±standard deviation) age was 82.3 ± 6.0 years old, 67% were male, and a Micra was implanted for 6.0 ± 6.4 months. High‐degree AV block was present in four patients, whereas five with predominantly intrinsic conduction required intermittent pacing for bradycardia. The mean interval between visits was 7.1 ± 0.6 months. Seven patients had normal sinus node function at both visits and were included in a paired analysis. Both ACC signal amplitude (visit 2‐visit 1 = 1.4 mG; 95% confidence interval [CI] [−25.8 to 28.4 mG]; P = 0.933) and AVS (visit 1: 90.8%, 95% CI [72.4, 97.4] and visit 2: 91.4%, 95% CI [63.8, 98.5]; P = 0.740) remained stable. Three patients had spontaneous atrial tachycardia. During atrial fibrillation, no atrial contraction was detected or tracked. During atrial flutter, intermittent tracking resulted in a ventricular rate of 60 ± 8 beats per minute (bpm); there was no ventricular pacing >100 bpm. Conclusion: ACC signals amplitude and performance of AVS pacing were stable over time. During atrial arrhythmias, the AV synchronous pacing mode behaved safely. [ABSTRACT FROM AUTHOR]

Different follow-up methods have been used to report success rates after AF ablation. Recent studies have shown that intermittent rhythm monitoring underestimates the actual AF recurrence rate. We therefore report our experience with continuous rhythm monitoring by implantable loop recorder (ILR) in a large patient cohort. Between 09/2008 and 12/2012, 343 cardiac surgical patients underwent concomitant surgical AF ablation. ILR implantation was performed in 206 patients. ILR interrogation was accomplished at 3, 6 and 12 months postoperatively. Successful ablation was defined as AF Burden <0.5 %. Primary outcome of the study was freedom from AF at 12-month follow-up. Mean patient's age was 70.5 ± 7.4 years. No major ablation- or ILR-related complications occurred. In 4 patients (1.9 %) ILR had to be explanted due to ILR-related wound infection ( n = 2) or chronic pain ( n = 2). Survival rate at 1-year follow-up was 96.6 %. Freedom from AF rate after 1-year follow-up was 68.5 and 63.6 % off antiarrhythmic drugs, respectively. Statistically significant predictors for successful ablation at 1-year follow-up were smaller LA diameter, shorter duration of AF and preoperative paroxysmal AF. Demographic data, indication for surgery, lesion set and used energy source had no impact on freedom from AF after 1 year. Continuous ILR monitoring after concomitant surgical AF ablation was safe and feasible, with registered freedom from AF rate of 68.5 % at 1-year follow-up. Thus continuous rhythm monitoring provides reliable outcome data and helps to guide antiarrhythmic therapy. [ABSTRACT FROM AUTHOR]

Background: Concomitant Surgical AF ablation is an established procedure, recommended in guidelines. However many surgeons are reluctant to perform AF ablation in patients with significantly enlarged left atrium. We therefore analyzed outcomes of patients with left-atrial diameter >55 mm undergoing concomitant AF ablation.Methods: Between 05/2003 and 12/2012 124 patients with significantly enlarged left-atrium >55 mm underwent concomitant surgical AF ablation. Rhythm monitoring was accomplished by implantable loop recorder (ILR) interrogation (n = 54), or 24-h Holter-ECG (n = 70). Successful ablation was defined as AF Burden <0.5 % in ILR interrogation or absence of AF episode >30 s in 24-h Holter-ECG. Primary endpoint of the study was freedom from AF at 12 months follow-up.Results: Mean patient's age was 65.7+/-9.6 years, 69.4 % were male. No major ablation or ILR related complications occurred. Mean LA diameter was 60.7+/-4.4 mm. Survival rate at one-year follow up was 94.4 %. 11 (8.8 %) patients received additional catheter-based ablation, while 23 (18.5 %) had an electrical cardioversion during follow-up period. Overall freedom from AF rate after one-year follow-up was 64.4 % and 59.4 % off antiarrhythmic drugs respectively. Logistic regression analysis identified preoperative paroxysmal AF, duration of AF and LA diameter > 70 mm as predictors for rhythm outcome at 12 months follow-up.Conclusion: In this patient cohort with significantly enlarged LA diameter, concomitant surgical AF ablation provided freedom from AF of 64.4 % after one-year follow-up. However in this patient population, an accurate postoperative care with interventions like medical or- electrical cardioversion and additional catheter based ablation is necessary to achieve satisfactory results. [ABSTRACT FROM AUTHOR]