ObjectiveTo investigate the natural outcome of spontaneous closure of iatrogenic atrial septal defect (IASD) in patients with atrial fibrillation after transseptal catheterization and the influencing factors affecting its healing.MethodsA total of 122 patients who underwent percutaneous left atrial appendage occlusion in West China Hospital, Sichuan University from September 2014 to February 2018 were selected for observation and follow-up. General information of the patients was collected. Each patient underwent transthoracic echocardiography and transesophageal echocardiography before the surgery or 45 days, 3 months, 6 months and 1 year after the surgery, observing the atrioventricular size, cardiac function and atrial septal defect size. The natural outcome of IASD and influencing factors and prognosis of IASD were analyzed.ResultsThe healing rate increased gradually with the follow-up time; the median healing time was 180 days [95% confidence interval (169.5, 190.5) days]. The difference in the effect on IASD healing rate between the gender and atrial fibrillation type was not significant (P>0.05); being older than 70 years old was the influence factor for the IASD healing rate (P<0.05). There was no statistically difference in right heart size and systolic and diastolic function between the unhealed group (n=18) and the healed group (n=63) after a 1-year follow-up (P>0.05), but the left ventricular size was bigger in the unhealed group than that in the healed group (P<0.05). The follow-up time points had a significant effect on the size of the left atrium, and the left atrium in the healing group after 1 year follow-up was significantly smaller than before. There was no significant difference among the different follow-up time points and no interaction between grouping and follow-up time (P>0.05). ConclusionsWith the extension of follow-up time, the healing rate increases gradually. Larger left atrium and ventricular size and the age over 70 may be related to the healing of IASD.