Additional LVZ-based substrate modification after PVI improved the outcome in PeAF patients with LVZs, whereas PVI alone worked in patients without LVZs, even in those with PeAF.

There was a significant slowing of local conduction in the LVZ defined as <0.5 mV and was frequently associated with fractionated or double potentials in patients with AF.

Background Atrial fibrillation (AF) is associated with heart failure (HF) rehospitalization in patients with heart failure with preserved ejection fraction (HFpEF). Objective We tested the hypothesis that catheter ablation of AF could reduce HF rehospitalization compared with conventional pharmacotherapy in patients with HFpEF. Methods Eighty‐five consecutive HFpEF (EF ≥ 50% and a history of HF hospitalization) patients diagnosed as AF by 12‐lead electrocardiogram were retrospectively analyzed. Thirty‐five patients who received catheter ablation (ABL group) were compared with 50 patients treated by antiarrhythmic drugs and/or beta‐blockers (CNT group). The primary endpoint was rehospitalization due to HF. Results The patients characteristics did not differ between the two groups including, age (71 ± 8 vs 71 ± 13 years; P = .637), female sex (34% vs 36%; P = .870), mean plasma brain natriuretic peptide (145 ± 112 vs 195 ± 153 pg/mL; P = .111), mean left ventricular ejection fraction (62% ± 8% vs 61% ± 9%; P = .624), and type of AF (nonparoxysmal AF 60% vs 62%; P = .852). Amiodarone was continued 40% (14 out of 35) and 40% (20 out of 70) in ABL and CNT groups, respectively (P = 1.000). Neither major complication nor major side effect was observed during the follow‐up period. During a mean follow‐up period of 792 ± 485 days, Kaplan‐Meier curve analysis showed that significantly more patients in the ABL group were free from HF rehospitalization (log‐rank P = .0039). Additionally, multivariate analysis revealed that catheter ablation of AF was the only preventive factor of HF rehospitalization (OR = 0.15; 95% CI: 0.04‐0.46; P < .001). Conclusions Catheter ablation of AF reduced HF rehospitalization compared with conventional pharmacotherapy in patients with HFpEF in our institute. Multicenter randomized study is warranted to confirm the result.

The LVZ area was an independent predictor of recurrence after PVAI without any LA substrate modification. Adenosine triphosphate-induced PV reconnection was also an independent predictor, especially in those without LVZs.

The extent of LVZ is an independent predictor for recurrence even after LVZ homogenization.

External anatomical structures contacting the LA may be related to unique conduction properties in diseased myocardium necessary for PsAF maintenance.

Background Low‐voltage areas (LVAs) in the atria of patients with atrial fibrillation are considered local fibrosis. We hypothesized that voltage reduction in the atria is a diffuse process associated with fibrosis and that the presence of LVAs reflects a global voltage reduction. Methods and Results We examined 140 patients with atrial fibrillation and 13 patients with a left accessory pathway (controls). High‐density bipolar voltage mapping was performed using a grid‐mapping catheter during high right atrial pacing. Global left atrial (LA) voltage (V GLA ) in the whole LA and regional LA voltage (V RLA ) in 6 anatomic regions were evaluated with the mean of the highest voltage at a sampling density of 1 cm 2 . Patients with atrial fibrillation were categorized into quartiles by V GLA . LVAs were evaluated at voltage cutoffs of 0.1, 0.5, 1.0, and 1.5 mV. Twenty‐eight patients with atrial fibrillation also underwent right atrial septum biopsy, and the fibrosis extent was quantified. Voltage at the biopsy site (V biopsy ) was recorded. V GLA results by category were Q1 (<4.2 mV), Q2 (4.2–5.6 mV), Q3 (5.7–7.0 mV), and Q4 (≥7.1 mV). V RLA at any region was reduced as V GLA decreased. V GLA and V RLA did not differ between Q4 and controls. The presence of LVAs increased as V GLA decreased at any voltage cutoff. Biopsies revealed 11±6% fibrosis, which was inversely correlated with both V biopsy and V GLA ( r =–0.71 and –0.72, respectively). V biopsy was correlated with V GLA ( r =0.82). Conclusions Voltage reduction in the LA is a diffuse process associated with fibrosis. Presence of LVAs reflects diffuse voltage reduction of the LA.

Non-PV foci are prevalent in the LA roof and SVC sites, but can originate from other sites as well. When non-PV foci are observed, PVI may be insufficient and should be supplemented with non-PV foci ablation.