Background— Current methods for detecting atrial fibrillation (AF) have limited diagnostic yield. Continuous monitoring with automatic arrhythmia detection and classification may improve detection of symptomatic and asymptomatic AF and subsequent patient treatment. The study purpose was to quantify the performance of the first implantable leadless cardiac monitor (ICM) with dedicated AF detection capabilities. Methods and Results— Patients (n=247) with an implanted ICM (Reveal XT, Medtronic Inc, Minneapolis, Minn) who were likely to present with paroxysmal AF were selected. A special Holter device stored 46 hours of subcutaneously recorded ECG, ICM markers, and 2 surface ECG leads. The ICM automatic arrhythmia classification was compared with the core laboratory classification of the surface ECG. Of the 206 analyzable Holter recordings collected, 76 (37%) contained at least 1 episode of core laboratory classified AF. The sensitivity, specificity, positive predictive value, and negative predictive value for identifying patients with any AF were 96.1%, 85.4%, 79.3%, and 97.4%, respectively. The AF burden measured with the ICM was very well correlated with the reference value derived from the Holter (Pearson coefficient=0.97). The overall accuracy of the ICM for detecting AF was 98.5%. Conclusions— In this ICM validation study, the dedicated AF detection algorithm reliably detected the presence or absence of AF and the AF burden was accurately quantified. The ICM is a promising new diagnostic and monitoring tool for the clinician to treat AF patients independently of symptoms. Long-term studies are needed to evaluate the clinical benefits of the technology. Clinical Trial Registration— clinicaltrials.gov Identifier NCT00680927.

Delay of progression from paroxysmal to persistent atrial fibrillation (AF) is an important measure of long-term success of AF treatment. However, published data on the impact of catheter ablation on AF progression are limited. This study evaluates whether radiofrequency (RF) catheter ablation delays the progression of AF compared with antiarrhythmic drug (AAD) treatment using current AF management guidelines. This prospective, randomized, controlled, two-arm, open-label trial was conducted at 29 hospitals and medical centres across 13 countries. Patients were randomized 1 : 1 to RF ablation or AAD treatment. The primary endpoint was the rate of persistent AF/atrial tachycardia (AT) at 3 years. After early study termination following slow enrolment, 255 (79%) of the planned 322 patients were enrolled (RF ablation, n = 128, AAD, n = 127); 36% of patients in the RF ablation group and 41% in the AAD group completed 3 years of follow-up. For the primary endpoint, the Kaplan–Meier estimate of the rate of persistent AF/AT at 3 years was significantly lower with RF ablation [2.4% (95% confidence interval (CI), 0.6–9.4%)] than with AAD therapy [17.5% (95% CI, 10.7–27.9%); one-sided P = 0.0009]. Patients ≥65 years were ∼4 times more likely to progress to persistent AF/AT than patients <65 years, suggesting RF ablation can delay disease progression [hazard ratio: 3.87 (95% CI, 0.88–17.00); P = 0.0727]. Primary adverse events were reported for eight patients in the RF ablation group. Radiofrequency ablation is superior to guideline-directed AAD therapy in delaying the progression from paroxysmal to persistent AF.

Background—: Cardiac tamponade is the most dramatic complication observed during atrial fibrillation (AF) ablation and the leading cause of procedure-related mortality. Female sex is a known risk factor for complications during AF ablation; however, it is unknown whether women have a higher risk of tamponade. Methods and Results—: A systematic Medline search was used to locate academic electrophysiological centers that reported cases of tamponade occurring during AF ablation. Centers were asked to provide information on cases of acute tamponade according to sex and their mode of management including any case of related mortality. Nineteen electrophysiological centers provided information on 34 943 ablation procedures involving 25 261 (72%) men. Overall, 289 (0.9%) cases of tamponade were reported: 120 (1.24%) in women and 169 (0.67%) in men (odds ratio, 1.83; P <0.001). There was a reciprocal association between center volume and the occurrence of tamponade with substantially lower risk in high-volume centers. Most cases of tamponade occurred during catheter manipulation or ablation; women tended to develop more tamponades during transseptal catheterization. No sex difference in the mode of management was observed. However, 16% cases of tamponade required surgery with lower rates in high-volume centers. Three cases of tamponade (1%) culminated in death. Conclusions—: Tamponade during AF ablation procedures is relatively rare. Women have an ≈2-fold higher risk for developing this complication. The risk of tamponade among women decreases substantially in high-volume centers. Surgical backup and acute management skills for treating tamponade are important in centers performing AF ablation.

Guidelines for the diagnosis and treatment of circulatory diseases in the context of the COVID-19 pandemic

Use of a non-invasive electrocardiographic mapping system may aid in rapid diagnosis of atrial or ventricular arrhythmias or the detection of ventricular dyssynchrony. The aim of the present study was to validate the mapping accuracy of a novel non-invasive epi- and endocardial electrophysiology system (NEEES). Patients underwent pre-procedural computed tomography or magnetic resonance imaging of the heart and torso. Radiographic data were merged with the data obtained from the NEEES during pacing from implanted pacemaker leads or pacing from endocardial sites using an electroanatomical mapping system (CARTO 3, Biosense Webster). The earliest activation as denoted on the NEEES three-dimensional heart model was compared with the true anatomic location of the tip of the pacemaker lead or the annotated pacing site on the CARTO 3 map. Twenty-nine patients [mean age: 62 ± 11 years, 6/29 (11%) female, 21/29 (72%) with ischaemic cardiomyopathy] were enrolled into the pacemaker verification group. The mean distance from the non-invasively predicted pacing site to the anatomic reference site was 10.8 ± 5.4 mm for the right atrium, 7.7 ± 5.8 mm for the right ventricle, and 7.9 ± 5.7 mm for the left ventricle activated via the coronary sinus lead. Five patients [mean age 65 ± 4 years, 2 (33%) females] underwent CARTO 3 verification study. The mean distance between non-invasively reconstructed pacing site and the reference pacing site was 7.4 ± 2.7 mm for the right atrium, 6.9 ± 2.3 mm for the left atrium, 6.5 ± 2.1 mm for the right ventricle, and 6.4 ± 2.2 for the left ventricle, respectively. The novel NEEES was able to correctly identify the site of pacing from various endo- and epicardial sites with high accuracy.

A new strategy for anatomically based ganglionated plexi (GP) ablation for the treatment of paroxysmal atrial fibrillation (AF) has been proposed recently. We aimed to assess the long-term outcome of patients undergoing anatomic GP ablation for paroxysmal AF, in comparison with circumferential pulmonary vein (PV) isolation. The study population consisted of 70 patients (mean age 56.6 ± 10.9 years; 41 males) with paroxysmal AF and no history of structural heart disease: 35 subjects underwent anatomic GP ablation, while 35 consecutive patients had circumferential PV isolation (CPVI) (control group). The groups were not different in demographic and clinical parameters. Anatomic GP ablation required more ablation points (85.6 ± 5.5 vs. 74.4 ± 6.2, P < 0.05) and equal duration of total procedure and fluoroscopy times. During a mean follow-up period of 36.3 ± 2.3 months, freedom from any atrial tachyarrhythmia without antiarrhythmics was achieved in 34.3% patients after anatomic GP ablation and 65.7% patients after CPVI (log-rank test P = 0.008). Early arrhythmia recurrences and anatomic GP ablation were independent predictors of late recurrence [HR 6.44 (CI 95%; 3.14–13.18; P < 0.001) and HR 2.08 (CI 95%; 1.03–4.22; P = 0.04), respectively]. Six patients in the group of GP ablation underwent subsequent CPVI, plus peri-mitral flutter ablation in two of them, with no further arrhythmia episodes in five patients. Anatomic GP ablation yields a significantly lower success rate over the long-term follow-up period, when compared with CPVI. Recurrences include AF and macro re-entrant atrial tachycardias.