Persistent iatrogenic atrial septal defect after pulmonary vein isolation by cryoballoon: an under-recognized complication

Aims Iatrogenic atrial septal defect (IASD) has been reported as a complication of transseptal puncture. This study aims to investigate the incidence, echocardiographic characteristics, and clinical outcome of persistent IASD after pulmonary vein isolation (PVI) by cryoballoon catheter delivered by a large transseptal sheath. Methods and results Thirteen patients (9 males, mean age 54.9 ± 13.0) with paroxysmal (10) or persistent (3) atrial fibrillation underwent PVI with cryoballoon catheter. Single transseptal puncture was performed with a BRK-1 shaped Brockenbrough needle and an 8 F sheath which was exchanged for a steerable transseptal sheath (15 F outer diameter and 12 F inner diameter) with the support of a stiff guidewire. Pulmonary vein isolation was performed with a 28 mm cryoballoon catheter. The incidence of persistent IASD was evaluated by transoesophageal echocardiography performed at 6 and 9 months after the procedure. At 6 months, five (38%) patients had persistent IASD with left-to-right shunt. The mean size of the IASD was 5.5 ± 2.4 mm. At 9 months, one patient had closure of the IASD and four (31%) patients had persistent IASD with mean size of 4.6 ± 1.4 mm. No patient died or suffered clinically from paradoxical embolism. Conclusions Persistent IASD is a common complication after PVI by cryoballoon catheter. Only left-to-right, but not right-to-left, interatrial shunting occurred as a result of the IASD. There was no clinical occurrence of paradoxical embolism. Patients should be screened for this complication after cryoballoon procedures and regular reassessment with echocardiographic or other techniques should be performed for monitoring.