Background-Identification of critical atrial substrates in patients with nonparoxysmal atrial fibrillation (AF) failing to respond to pulmonary vein isolation is important. This study investigated the signal characteristics, substrate nature, and ablation results of rotors during AF. Methods and Results-In total, 53 patients (age=55±8), 31 with persistent AF and 22 with long-lasting AF, underwent pulmonary vein isolation and substrate modification of complex fractionated atrial electrograms. Small-radius-reentrant rotors were identified from signal analyses of the dominant frequency and fractionation interval and nonlinear analyses (newly developed, beat-to-beat nonlinear measurement of the repetitiveness of the electrogram morphology >6 seconds). In 15% of the patients, activation maps demonstrated occurrences of rotor-like small-radius reentrant circuits (n=9; 1.1 per patient; cycle length=110±21 ms; diameter=11±6 mm) with fibrillation occurring outside these areas. Rotors were identified by conventional point-by-point mapping and signal analyses and were subsequently eradicated by catheter ablation in these patients. Persistent AF for <1 year, a smaller left atrial size, substrates with higher mean voltages and shorter total activation durations predicted a higher incidence of rotors (all P<0.05). In the multivariable model, areas of reentrant circuits exhibited a higher dominant frequency, kurtosis, and higher degree of a beat-to-beat electrogram similarity than areas without or outside the rotors (all P<0.05). Conclusions-Rotor-like re-entry with fibrillatory conduction was found in a limited number of patients with nonparoxysmal AF after pulmonary vein isolation. Those areas were characterized by rapid repetitive activity with a high degree of electrogram similarity. Methods Patient CharacteristicsWe enrolled 53 patients (55±8 years) with symptomatic drug-refractory nonparoxysmal AF who underwent radiofrequency ablation guided by NavX system (St Jude Medical Inc, MN). The study cohort included 31 patients (58%) with persistent AF (duration <1 year but >7 days) and 22 patients (42%) with long-lasting persistent AF (duration of ≥1 year; Table 1). All patients presented with incessant AF in the beginning of the procedure. The patients were excluded from the study if they were in sinus rhythm or had spontaneous termination of AF before the PVI. Electrophysiological StudyAn electrophysiological study and catheter ablation in the fasting state were performed in each patient after informed consent was obtained. All antiarrhythmic drugs, except amiodarone, were discontinued for ≥5 half-lives before the start of the procedure. Overall, 19 patients (36%) were treated with amiodarone before the procedure because of symptomatic AF, but no patients received that drug during the electrophysiological procedure. Electroanatomic mapping was performed in all patients. The details of the mapping have been described in other previous studies. 10,11 Signal Acquisition and Linear AnalysisDuring AF, point-by-point mapping was ...

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1,25[OH]2 D has direct electromechanical effects on the LA and can prevent or terminate AF.

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Background Left atrial appendage (LAA) closure device is an alternative to anticoagulants for stroke prevention in selected atrial fibrillation (AF) patients. The LAA device implantation is safe with short period of learning curve. The standard implantation technique warrants a transesophageal echocardiography (TEE) guided and general anesthesia. In region of Asia Pacific as well as Indonesia, both TEE and general anesthesia are not always available in district hospital. We studied the safety and efficacy of Amplatzer Cardiac Plug (ACP) implantation guided by fluoroscopy only and without general anesthesia. Methods Consecutive nonvalvular AF patients with CHA 2 DS 2 VASc score of ≥2 and HASBLED score of ≥3 are participated. Patients requiring long‐life anticoagulant for any other indication are excluded. The choice of implanted first or second‐generation ACP is that with excess size of 2‐4 mm of measured landing zone diameter. Results Twenty‐five subjects were implanted ACP by means fluoroscopy only (Group A) and 28 subjects using standard technique group (Group B). The median AF duration was 36 months (6‐276 months) and majority of patients (49%) are having permanent AF. The mean CHA2DS2VASc score is 3.9 ± 1.63. Successful implantation of ACPs was 96% in both groups. Nonfatal pericardial effusion occurred in three patients. During 75 weeks of follow‐up period, there were no significant differences of stroke event and death between groups. Conclusion ACP implantation guided with fluoroscopy only is feasible and safe.