oop recorders, the recurrence of AF in patients who develop transient POAF is common in the first month postoperatively. Of the patients who developed postoperative AF, 76% had any recurrence in months 1 to 12, and 30% had any recurrence beyond 1-year follow-up. Current guidelines recommend anticoagulation for POAF for 30 days. The results of this study warrant further investigation into continued monitoring and longer-term anticoagulation in this population within the context of our findings that AF duration was less than 30 minutes beyond 1 month. This study sought to determine whether durable pulmonary vein isolation (PVI) using pulsed field ablation (PFA) translates to freedom from atrial fibrillation recurrence without an increase in adverse events. PFA is a nonthermal ablative modality that, in preclinical studies, is able to preferentially ablate myocardial tissue with minimal effect on surrounding tissues. Herein, we present 1-year clinical outcomes of PFA. In 3 multicenter studies (IMPULSE [A Safety and Feasibility Study of the IOWA Approach Endocardial Ablation System to Treat Atrial Fibrillation], PEFCAT [A Safety and Feasibility Study of the FARAPULSE Endocardial Ablation System to Treat Paroxysmal Atrial Fibrillation], and PEFCAT II [Expanded Safety and Feasibility Study of the FARAPULSE Endocardial Multi Ablation System to Treat Paroxysmal Atrial Fibrillation]), paroxysmal atrial fibrillation patients underwent PVI using a basket or flower PFA catheter. Invasive remapping was performed at ∼2 to 3months, and reconnected PVs were reisolpanded Safety and Feasibility Study of the FARAPULSE Endocardial Multi Ablation System to Treat Paroxysmal Atrial Fibrillation [PEFCAT II], NCT04170608). This study analyzed the predictors of defibrillation safety margin (DSM) testing at the time of implantable cardioverter-defibrillator (ICD) insertion and factors associated with inadequate DSM in patients with congenital heart disease (CHD). There are few data about the prevalence and safety of DSM testing in those with CHD. A retrospective analysis was performed of all patients with atrial or ventricular septal defect, tetralogy of Fallot, transposition of the great vessels, Ebstein anomaly, or common ventricle undergoing a transvenous ICD procedure in the National Cardiovascular Data Registry (NCDR) ICD Registry from April 2010 to March 2016, and DSM testing was assessed. Inadequate DSM was defined as a lowest successful energy tested<10J than the maximum output of the ICD generator. Of all ICD recipients (N=7,024), DSM testing was performed in 52.0% (n=3,654). The mean lowest successful energy tested was 20.7 ± 7.3 J. Of those with DSM adequacy data available (n=3,623), an inadequate DSM occurred in 13.8% (n=501). After multivariable adjustment, DSM testing was not associated with in-hospital complications or death (odds ratio [OR] 1.00; 95% confidence interval [CI] 0.79 to 1.28) but was associated with lower odds of prolonged hospital stay (>3days) (OR 0.71; 95%CI 0.60 to 0.84; p<0.0001). An inadequate DSM was not associated with in-hospital death or complications (OR 1.27; 95%CI 0.79 to 2.04) or prolonged hospital stay (OR 1.34; 95%CI 0.995 to 1.81). DSM testing is being performed less frequently over time and seems safe in those with CHD. An inadequate DSM was not associated with worse in-hospital outcomes.DSM testing is being performed less frequently over time and seems safe in those with CHD. An inadequate DSM was not associated with worse in-hospital outcomes. This study reports the sensing and arrhythmia detection performance of a novel extravascular (EV) implantable cardioverter-defibrillator (ICD) in a first-in-human pilot study. The EV ICD lead is implanted in the substernal space, resulting in novel sensing and detection challenges. It uses a programmable sensing profile with new or modified discrimination of oversensing and of ventricular tachycardia (VT) from supraventricular tachycardia (SVT). Electrograms were post-processed from induced ventricular fibrillation (VF) at implant to determine virtual detection times for each programmable sensitivity and the least-sensitive safe sensitivity setting. In ambulatory patients, programmed sensitivity provided at least a twofold safety margin for detecting induced VF. Noise discrimination was stress tested, and the effects of source, posture, and lead maturation were determined on electrogram amplitude. read more Telemetry Holter monitors were used to quantify undersensing and oversensing. In 20 patients at implant, the least-sensitive safe sensitivity for VF detection ranged from 0.1 to 0.6mV. Seventeen patients were followed up for a total of 16.6 patient-years. Electrogram amplitudes were stable over time, but there were significant differences among postures and sensing vectors. For the primary sensing vector, the weighted oversensing and undersensing rates were 1.03% and 0.40% respectively, on a beat-to-beat basis. Oversensing did not cause inappropriate therapy in patients with in situ leads. Oversensing discriminators withheld VF detection in 4 of 5 spontaneous, sustained oversensed episodes. SVT-VT discriminators correctly classified 93% of 128 sustained SVTs in monitor zones. In the EV ICD pilot study, oversensing did not cause inappropriate therapy during ambulatory follow-up of stable leads.In the EV ICD pilot study, oversensing did not cause inappropriate therapy during ambulatory follow-up of stable leads. This study sought to investigate the mortality associated with atrial fibrillation (AF) in men and women with heart failure (HF) according to the sequence of presentation and rhythm versus rate control. The sex-specific epidemiology of AF in HF is sparse. Using the Danish nationwide registries, all first-time cases of HF were identified and followed for all-cause mortality from 1998 to2018. Among 252,988 patients with HF (mean age 74 ± 13 years, 45% women), AF presented before HF in 54,064 (21%) and on the same day in 27,651 (11%) individuals, similar in women and men. Among patients without AF, the cumulative 10-year incidence of AF was 18.7% (95% confidence interval [CI] 18.2% to 19.1%) in women and 21.3% (95%CI 21.0% to 21.6%) in men. On follow-up (mean 6.2 ± 5.8 years), adjusted mortality rate ratios were 3.33 (95%CI 3.25 to 3.41) in women and 2.84 (95%CI 2.78 to 2.90) in men if AF antedated HF, 3.45 (95%CI 3.37 to 3.56) in women versus 2.76 (95%CI 2.69 to 2.83) in men when AF and HF were diagnosed concomitantly, and 4.