BACKGROUND: Very-high-power short-duration (vHPSD) radiofrequency (RF) ablation is expected to make shallow lesions and reduce collateral damage. This study investigated the power setting and quality of acute lesions performed by a modified vHPSD RF ablation guided by left atrial (LA) voltage around the esophagus. METHODS: A voltage map was obtained by an OCTARAY catheter (3-mm spacing) during pacing from the high right atrium. The power setting of the vHPSD was modified according to the LA voltage around the esophagus: 65 W for <
1.8 mV, 75 W for <
2.7 mV, and 90 W for ≥2.7 mV. The incidence of gaps after the 1st pass and spontaneous, isoproterenol-induced, and adenosine-induced reconnections were evaluated. The limit of esophagus temperature rise was set at 40 °C. Gastric hypomotility was assessed. RESULTS: A modified vHPSD RF ablation guided by the LA voltage was performed for 450 lesions in 32 patients (median age 73 years, 15 females). The RF setting was 65 W for 221 lesions (49 %), 75 W for 104 lesions (23 %), and 90 W for 125 lesions (28 %). Gaps after the 1st pass were observed in 3 patients (9.4 %). Any reconnections were observed in 6 patients (19 %). Esophageal temperature rises of >
40 °C were observed at 39 lesions. RF ablation at the areas modified to 65 W more frequently resulted in esophageal temperature rise of >
40 °C than the areas modified to 75 W or 90 W (12 % vs. 5.2 %, p = 0.017). No-gap-no-reconnection lesions were more frequently achieved for lesions ablated with 65 W (216/221 lesions, 98 %) than for lesions ablated with 90 W (113/125 lesions, 90 %, p = 0.004). No gastric hypomotility and atrio-esophageal fistulae were observed. CONCLUSIONS: The modified vHPSD RF ablation guided by the LA voltage was a reasonable option for reducing the power setting without compromising the acute pulmonary vein isolation quality.