Perspectives on Catheter Ablation of Atrial Fibrillation

Abstract

Circulation Journal Official Journal of the Japanese Circulation Society http://www. j-circ.or.jpAlthough the percentage of persistent AF differed between the studies (77% vs. 36%), a speculation that may come to mind is that diastolic dysfunction may be associated with progression of the atrial substrate, and that PV isolation is inadequate in patients with diastolic dysfunction. Hemodynamic deterioration during AF affects patients with LV systolic or diastolic dysfunction to a greater extent, compared with those with lone AF. Thus, benefit of maintaining sinus rhythm is greatly anticipated in patients with LV dysfunction. However, AF patients with LV dysfunction are likely to have greater structural and electrophysiological remodeling of the atria, and therefore would be associated with poor clinical outcomes after ablation. To improve the clinical outcomes in AF patients with advanced atrial remodeling, the development of new ablation techniques to eliminate atrial substrates or mapping technologies for understanding fibrillatory process ongoing after PV isolation is needed.The postablation management of patients with HCM remains to be fully discussed. A recent study demonstrated that the arrhythmia-free rate was 76% at 1 year after AF ablation, but decreased to 49% at 3.5 years of follow-up in patients with HCM, and that the mechanism of the late recurrences was non-PV triggers. 9 That study suggested that the atrial substrate or triggers develop even if sinus rhythm is maintained for more than 1 year. In the study by Okamatsu et al, 10 patients were followed for less than 2 years, and an association between E/e' and late recurrence was not investigated. Another issue is the use of antiarrhythmic drugs. Although the safety of disopyramide in obstructive HCM patients was shown by an observational cohort study, 11 limited data are available on the safety of the use of antiarrhythmic drugs in patients with non-obstructive HCM. Antiarrhythmic drugs were given to 68% of patients in the study by Okamatsu et al. 10 Presumably, the maintenance of sinus rhythm with the use of antiarrhythmic drugs was beneficial in terms of quality of life during the mid-term follow-up, but we must remember the potential risk of sudden cardiac death. In addition, the efficacy of antiarrhythmic drugs has become reduced over the years, 12 suggesting a limited effects of these drugs against the progression of AF. We must therefore deliberately use antiarrhythmic drugs after catheter ablation with the knowledge that the long-term clinical outcome of a hybrid therapy of ablation and antiarrhythmic drugs is unclear.Catheter ablation of AF is now effective in 70% of patients with HCM with use of antiarrhythmic drugs, repeat procedures or extensive atrial ablation adjunctive to PV isolation. The maintenance of sinus rhythm greatly improves the quality trial fibrillation (AF) is the most common tachyarrhythmia in clinical practice, and the number of patients is now estimated at nearly 1 million in Japan. The development of novel oral anticoagu...