br Disclosures br Acknowledgments br Introduction Long term
Introduction Long-term endurance sports have recently been recognized as one of the risk factors for atrial fibrillation (AF) [1–8]; widely accepted risk factors for AF include age, hypertension, diabetes mellitus, structural Epoxomicin disease, hyperthyroidism, obesity, and heavy alcohol intake [9–12], although moderate physical activity may decrease the risk of AF . Elosua et al.  reported that a lifetime of sport activities of at least 1500h is associated with a higher risk of AF, and there are increasing data that AF is 2–10 times more prevalent in active or former athletes in Europe and America [1–8]. A substantial number of endurance athletes experience AF in Japan, which may be explained by the rise in popularity of jogging among the Japanese, but the connection remains unclear. AF has been reported to originate in the pulmonary vein (PV) in the majority of patients with paroxysmal AF and in a substantial number of patients with persistent AF [14,15]; PV antrum isolation (PVAI) eliminates AF in these patients [16,17]. However, the mechanism underlying the relationship of AF with endurance sports remains unclear, and there are limited data regarding the efficacy of PV isolation for AF [18,19]. Therefore, this study aimed to characterize AF in endurance athletes and to examine the efficacy of PVAI in an attempt to clarify the mechanism.
Conflict of interest
Introduction Lone atrial fibrillation (AF) was first proposed by Evans and Swann in 1954  and was defined as AF occurring in the absence of any other clinical evidence suggesting a primary cardiac disorder or coexisting coronary heart disease, heart failure, rheumatic heart disease, or hypertensive cardiovascular disease. The clinical course of lone AF was studied by Jahangir et al., who suggested there was a relatively low risk of thromboembolic complications, heart failure, and mortality . Patients with lone AF were initially thought to have a normal life expectancy and a good prognosis [2,3]. However, recent data have revealed different results. In the Paris Prospective Study I, idiopathic AF was associated with a higher mortality in middle-aged Frenchmen with a long follow-up period . Some other studies showed that a subgroup of patients with lone AF may have a substantially increased risk for thromboembolic events [5,6]. Thus, we asked, “Does lone AF exist”? The answer relies on the definition of lone AF and on how in-depth one investigates the patient co-morbidities . A previous study demonstrated that abnormal atrial histology (as a consistent organic substrate) was uniformly distributed in the interatrial septum of all patients with lone AF . However, there has been relatively limited information regarding the clinical characteristics of lone AF. In addition, data on the electroanatomical characteristics of lone AF are sparse. The aim of this study was to investigate the clinical and electroanatomical characteristics of patients with paroxysmal lone AF.
Introduction Bepridil (Bep) has been reported to be effective for treating persistent atrial fibrillation (AF), and atrial flutter (AFL) by converting and maintaining sinus rhythm [1–8]. In addition, a reverse remodeling effect in the atrium has been recognized in animal models of AF [9,10]. However, serious adverse effects have been noted in clinical trials [11–14]. In particular, torsarde de points (TdP) with marked QT prolongation is a life-threatening event. Yasuda et al.  reported adverse effects in 4% of the patients treated with Bep and Tdp in 0.9% of these patients. In the J-BAF study , although Bep effectively maintained sinus rhythm, there was a high recurrence rate of AF and one case of sudden cardiac death. Therefore, it remains important to carefully consider the safety of Bep when selecting a rhythm control strategy. Kurita et al.  reported that Tdp occurred in patients with a serum Bep concentration (SBC)≥500ng/ml. Recently, SBC was suggested to be useful for selecting the maintenance dose of Bep [17–19]. However, very limited data on this issue are available. The aim of this study was to evaluate the clinical significance of SBC for the safe management of patients with atrial tachyarrhythmia (AT).