Incidence and predictors of persistent iatrogenic atrial septal defect following catheter ablation.

Background: The left atrium approach for atrial fibrillation (AF) ablation requires an atrial transseptal puncture that may cause an iatrogenic atrial septal defect (iASD). This study aimed to investigate the incidence and predictors of iASD in catheter ablation, assessed by transthoracic echocardiography (TTE), a relatively non-invasive technique frequently employed in follow-up.

Methods: This retrospective study included 639 patients (489 male; 60.2±10.7years) who underwent initial catheter ablation for AF between May 2005 and June 2018. All patients underwent preprocedural transesophageal echocardiography (pre-TEE), preprocedural TTE (pre-TTE), and TTE one day after the procedure (post-TTE). iASD incidence after 6months (6M), preprocedural characteristics, and procedure methods were evaluated.

Results: Patent foramen ovale (PFO) was diagnosed in 42 patients (6.6%) using pre-TEE and in 11 patients using pre-TTE (26.2% of the patients with PFO in pre-TEE). Among the 597 patients without PFO, 497 underwent 6M-TTE. iASD was observed in 59.6% of patients using post-TTE and 4.6% using 6M-TTE. In the univariate logistic regression analysis, the total diameter of the sheath through the septum (odds ratio 1.15, p<0.001) or two sheaths through a single puncture (odds ratio 4.17, p=0.001) were independent risk factors on iASD incidence in 6M-TTE. iASD was also more likely to occur via cryoballoon ablation using a larger sheath than radiofrequency catheter ablation.

Conclusions: iASD was not a rare complication. A larger sheath diameter or two sheaths through a single puncture were associated with the incidence of iASD.