Characteristics of Low-Voltage Zones in Patients With Heart Failure With Preserved Ejection Fraction.

BACKGROUND: Atrial fibrillation (AF) frequently coexists with heart failure with preserved ejection fraction (HFpEF), and low-voltage zones (LVZs) in the atria represent atrial remodeling. However, the impact of HFpEF on the extent and distribution of LVZs and ablation outcomes remains unknown. OBJECTIVE: To characterize LVZs in patients with HFpEF undergoing AF ablation and evaluate their association with arrhythmia recurrence. METHODS: A total of 128 consecutive patients (66±12 years) who underwent AF ablation for the first time were retrospectively analyzed. HFpEF was defined as a left ventricular ejection fraction >50% with a history of heart failure treatment or an HFA-PEFF score ≥5. Meanwhile, LVZs were defined as bipolar voltage <0.5 mV and quantified across five left atrial regions. RESULTS: Forty-seven patients (36.7%) were diagnosed with HFpEF. LVZs were significantly more extensive in the overall left atrium in the HFpEF group (16.3±13.5 vs. 8.2±7.6 cm2, p < 0.001), with the greatest difference being observed in the anterior wall (5.6±5.4 vs. 2.3±2.8 cm2, p < 0.001). During 9±4 months, arrhythmia recurrence rates did not differ significantly between HFpEF and non-HFpEF groups (12.8% vs. 13.6%, p = 0.310). Posterior wall isolation was more frequently performed in the HFpEF group (27.6% vs. 4.9%, p < 0.001). In multivariable analysis, HFpEF, age, and persistent AF were independent determinants of LVZ extent. CONCLUSIONS: AF patients with HFpEF exhibit more extensive LVZs, indicating advanced atrial remodeling. Despite differences in atrial substrate and ablation strategy, arrhythmia recurrence rates were comparable between patients with and without HFpEF.