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Death and rehospitalization in acute decompensated heart failure (ADHF) patients still has not shown improvement despite continuous development in the field of cardiovascular therapy. The main problem with ADHF is activation of the renin-angiotensin-aldosterone (RAA). In addition, the administration

Dronedarone and amiodarone are anti-atrial fibrillation agents with different potency. Pulmonary veins play a critical role in the genesis of atrial fibrillation. Oxidative stress can enhance pulmonary vein arrhythmogenesis. This study was done to compare the effects of dronedarone and amiodarone on pulmonary vein electrophysiological and mechanical properties, and oxidative stress-induced arrhythmogenecity. Conventional microelectrodes were used to record action potentials in isolated rabbit pulmonary vein specimens before and after dronedarone and amiodarone with or without the presence of H2O2 (2mM). Dronedarone (0.1, 1 and 10 μM) concentration-dependently decreased pulmonary vein beating rates (from 2.2±0.1 to 1.9±0.1, 1.8±0.1 and 1.7±0.1Hz, n=8, P

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 P P 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.