Prevalence and characteristics of asymptomatic excessive transmural injury after radiofrequency catheter ablation of atrial fibrillation.

Background: Even with a low energy setting, radiofrequency energy applications on the left atrial (LA) posterior wall may cause excessive transmural injury (ETI) during catheter ablation of atrial fibrillation (AF).

Objective: The purpose of this study was to clarify the prevalence and characteristics of ETI.

Methods: This study included 104 patients with AF who underwent extensive encircling pulmonary vein isolation (EEPVI) followed by an endoscopic examination (≤48 hours after EEPVI). EEPVI was performed under conscious sedation, and the ablation settings at the LA posterior wall were a maximum energy of 20 to 25 W and duration of ≤30 seconds. The ETI was defined as any injury that resulted from EEPVI, including esophageal damage or periesophageal nerve injury.

Results: ETIs were found in 10 (9.6%) patients and were all asymptomatic; esophageal damage in 4 patients and periesophageal nerve injury in the remaining 6. All patients with ETI were below normal weight (body mass index [BMI] < 24.9 kg/m(2)), and consisted of 17% of those below normal weight. The procedural parameters such as the type of energy source, total duration of energy applications to the LA posterior wall, additional LA linear ablation, and biochemical markers were not related to the ETI. In the logistic multiadjusted model, the BMI (per 1 kg/m(2)) was the only independent predictor of ETI (odds ratio = 0.76; 95% confidence interval = 0.59 to 0.97, P < .05).

Conclusion: Asymptomatic ETIs were not rare even with a low energy setting in patients below normal weight. Tailored energy settings based on the patient's BMI may be required when performing EEPVI.