nampt inhibitor br Do we need complete

Do we need complete isolation of all PVs in every patient? Circumferential PVI results in satisfactory outcomes for ablation of paroxysmal AF, and electrical isolation of all PVs is currently a standard approach to the treatment of AF, as recommended by the expert consensus statement [6]. Complete isolation also seems to be important for preventing recurrent atrial tachycardia during follow-up [25–27]. However, it is not clear whether all patients with AF need to undergo isolation of all PVs. A number of studies have reported favorable outcomes with an ablation strategy that does not include PVI. Lemola et al. reported that a successful outcome after LA ablation was found to be independent of the number of PVs that were electrically isolated. Therefore, complete isolation of the PVs was not necessary for a successful outcome [21]. Oral et al. reported that a tailored ablation strategy that targeted driver tachycardias and complex electrograms in the selected PVs resulted in freedom from recurrent AF in ∼80% of patients with paroxysmal AF [28]. Pokushalov et al. reported that selective ganglionated plexi ablation directed by an anatomic approach resulted in successful outcomes in ∼80% of patients with paroxysmal AF [29]. In the Pratola et al. study [29], patients with persistent AF who underwent PVI and did not have AF recurrence underwent repeated electrophysiological studies. Notably, PVI persisted in only ∼40% of the previously isolated PVs. This study supported the idea that atrial substrate also plays an important role in the persistence of AF, and the presence of PV reconnection does not necessarily mean recurrence of AF [30]. In contrast, there is consensus that in the majority of patients, AF recurs in association with recovered PV conduction. In a long follow-up study (median follow-up nampt inhibitor of 4.8 years), recovered PV conduction was observed in 62 of 66 patients (94%) at the 2nd ablation procedure [31]. The discrepancy in the impact of PVI on the maintenance of sinus rhythm may be explained by the interaction of a trigger and a substrate. The presence of AF substrate in addition to PV reconnection makes the atria more susceptible to recurrent AF than does PV reconnection alone. However, little data directly supports this notion because the actual prevalence of PV reconnections in patients free from recurrence of AF cannot be evaluated in routine clinical practice.
Relation between hemodynamic status and AF AF and heart failure create a vicious circle: heart failure promotes AF, and AF aggravates heart failure. In patients with symptomatic heart failure, the prevalence of AF ranges from 10 to 30% [32]. The importance of atrial stretch associated with an increase in atrial pressure in the maintenance of AF has been reported in animal models [33] and in patients with AF [34]. In the human study, patients with persistent AF had significantly higher LA pressures than did patients with paroxysmal AF. The atrial activation rate is known to be higher in patients with persistent AF than in patients with paroxysmal AF. Higher LA pressure may result in a greater degree of stretch-related electrical remodeling and an increase in atrial activation rate, making spontaneous termination of AF less likely. A potential new risk factor for AF, stiff LA syndrome, was recently proposed. The syndrome itself was originally reported in the late 1980s [35]. Its principal feature is that right heart failure is disproportionate to left heart failure because of reduced LA compliance or LA diastolic dysfunction. Recent studies have indicated that one of the causes of the syndrome was LA ablation for AF [36,37]. Machino-Ohtsuka et al. reported that pre-existing LA stiffness was related to AF recurrence after ablation [38]. Using magnetocardiography analysis, Sato et al. showed that right atrial overload possibly due to decreased LA compliance after LA ablation was associated with AF recurrence after ablation [39].