Background: Advanced generation ablation technologies have been developed to achieve more effective pulmonary vein isolation (PVI) and minimize arrhythmia recurrence after atrial fibrillation (AF) ablation. Methods: We randomly assigned 346 patients with drug-refractory paroxysmal AF to contact force–guided radiofrequency ablation (CF-RF; n=115), 4-minute cryoballoon ablation (Cryo-4; n=115), or 2-minute cryoballoon ablation (Cryo-2; n=116). Follow-up was 12 months. The primary outcome was time to first documented recurrence of symptomatic or asymptomatic atrial tachyarrhythmia (AF, atrial flutter, or atrial tachycardia) between days 91 and 365 after ablation or a repeat ablation procedure at any time. Secondary end points included freedom from symptomatic arrhythmia and AF burden. All patients received an implantable loop recorder. Results: One-year freedom from atrial tachyarrhythmia defined by continuous rhythm monitoring was 53.9%, 52.2%, and 51.7% with CF-RF, Cryo-4, and Cryo-2, respectively ( P =0.87). One-year freedom from symptomatic atrial tachyarrhythmia defined by continuous rhythm monitoring was 79.1%, 78.2%, and 73.3% with CF-RF, Cryo-4, and Cryo-2, respectively ( P =0.26). Compared with the monitoring period before ablation, AF burden was reduced by a median of 99.3% (interquartile range, 67.8%–100.0%) with CF-RF, 99.9% (interquartile range, 65.3%–100.0%) with Cryo-4, and 98.4% (interquartile range, 56.2%–100.0%) with Cryo-2 ( P =0.36). Serious adverse events occurred in 3 patients (2.6%) in the CF-RF group, 6 patients (5.3%) in the Cryo-4 group, and 7 patients (6.0%) in the Cryo-2 group, with no significant difference between groups ( P =0.24). The CF-RF group had a significantly longer procedure duration but significantly shorter fluoroscopy exposure ( P <0.001 vs cryoballoon groups). Conclusions: In this multicenter, randomized, single-blinded trial, CF-RF and 2 different regimens of cryoballoon ablation resulted in no difference in 1-year efficacy, which was 53% by time to first recurrence but >98% burden reduction as assessed by continuous cardiac rhythm monitoring. Clinical Trial Registration: URL: https://www.clinicaltrials.gov . Unique identifier: NCT01913522.

Background-Phrenic nerve palsy remains the most frequent complication associated with cryoballoon-based pulmonary vein (PV) isolation. We sought to characterize our experience using a novel monitoring technique for the prevention of phrenic nerve palsy. Methods and Results-Two hundred consecutive cryoballoon-based PV isolation procedures between October 2010and October 2013 were studied. In addition to standard abdominal palpation during right phrenic nerve pacing from the superior vena cava, all patients underwent diaphragmatic electromyographic monitoring using surface electrodes. Cryoablation was terminated on any perceived reduction in diaphragmatic motion or a 30% decrease in the compound motor action potential (CMAP). During right-sided ablation, a ≥30% reduction in CMAP amplitude occurred in 49 patients (24.5%). Diaphragmatic motion decreased in 30 of 49 patients and was preceded by a 30% reduction in CMAP amplitude in all. In 82% of cases, this reduction in CMAP amplitude occurred during right superior PV isolation. The baseline CMAP amplitude was 946.5±609.2 mV and decreased by 13.8±13.8% at the end of application. This decrease was more marked in the 33 PVs with a reduction in diaphragmatic motion than in those without (40.9±15.3% versus 11.3±10.5%; P<0.001). In 3 cases, phrenic nerve palsy persisted beyond the end of the procedure, with all cases recovering within 6 months. Despite the shortened application all veins were isolated. At repeat procedure the right-sided PVs reconnected less frequently than the left-sided PVs in those with phrenic nerve palsy. Conclusions-Electromyographic phrenic nerve monitoring using the surface CMAP is reliable, easy to perform, and offers an early warning to impending phrenic nerve injury. (Circ Arrhythm Electrophysiol. 2014;7:605-611.)

Background-Early recurrences (ERs) of atrial tachyarrhythmia are common after catheter ablation of atrial fibrillation. A 3-month blanking period is recommended by current guidelines. This study sought to investigate the significance of ER during the first 3 months post ablation in predicting late recurrences and determine whether it varies according to timing. Methods and Results-A total of 401 patients with paroxysmal atrial fibrillation undergoing pulmonary vein isolation were followed for 12 months with transtelephonic monitoring in the ADVICE (Adenosine Following Pulmonary Vein Isolation to Target Dormant Conduction Elimination) trial. Patients with atrial tachyarrhythmia ≥30 s within the 3-month blanking period were stratified according to the timing of ER. A total of 179 patients (44.6%) experienced their last episode of ER during the first (n=53), second (n=44), or third (n=82) month of the 3-month blanking period. One-year freedom from symptomatic atrial tachyarrhythmia was 77.2% in patients without ER compared with 62.6%, 36.4%, and 7.8% in patients with ER 1, 2, and 3 months post ablation, respectively (P<0.0001). Receiver operating curve analyses revealed a strong correlation between the timing of ER and late recurrence (area under the curve 0.82, P<0.0001). Corresponding hazard ratios for ER during the first, second, and third months were 1.84, 4.45, and 9.64, respectively. Conclusions-This study validates the use of a blanking period after catheter ablation for paroxysmal atrial fibrillation but calls into question the 90-day cut-off value. In particular, >90% of patients with ER during the third month post ablation experience late recurrence by 1 year. However, pending further study, repeat ablation before 90 days cannot be routinely advocated. Clinical Trial Registration-URL: http://www.clinicaltrials.gov. Unique identifier: NCT01058980.(Circ Arrhythm Electrophysiol. 2016;9:e003909.

In propensity-matched analyses, beta-blockers were associated with significantly lower mortality but not hospitalizations in patients with HFrEF and AF, irrespective of the pattern or burden of AF. These results support current evidence-based recommendations for beta-blockers in patients with HFrEF, whether or not they have associated AF.

Atrial fibrillation (AF) is the most frequent arrhythmia worldwide. While mostly seen in elderly, it can also affect young adults (≤ 45 years of age), older adolescent, and children. Areas covered: The aim of this review is to provide an overview of the current management of AF in young patients. Specific issues arise over diagnostic workup as well as antiarrhythmic and anticoagulation therapies. The future management and diagnostic strategies are also discussed. Expert commentary: Management of AF in the young adult is largely extrapolated from adult studies and guidelines. In this population, AF could reveal a genetic pathology (e.g. Brugada, Long QT or Short QT syndromes) or be the initial presentation of a cardiomyopathy. Therefore, thorough workup in the young population to eliminate potential malignant pathology.

Catheter ablation of AFL guided by real-time CF assessment results in a significant reduction in total RF delivery time. Real-time CF measurements facilitate the maintenance of homogenous efficient contact all along the CTI, particularly in the anterior segment where CF is generally lower.

In patients with a history of atrial fibrillation, an elevated baseline heart rate in sinus rhythm is independently associated with mortality. In contrast, the baseline heart rate in atrial fibrillation is not associated with mortality but predicts hospitalizations.

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