Transseptal left heart catheterization and the incidence of persistent iatrogenic atrial septal defects

Access to the left atrium for invasive and interventional cardiac procedures requires a transseptal (TS) puncture that creates an iatrogenic atrial septal defect (iASD). The utilization of TS access is increasing in cardiology, and the frequency of iASD is, therefore, likely to increase as well. Here, we discuss the TS technique, review existing series of iASD with regard to incidence and clinical significance of residual iASD, and present emerging techniques utilizing TS access where iASD may result.

A PubMed search for "iatrogenic atrial septal defects" was performed to identify prospective series addressing the incidence of iASDs after TS procedures. We identified 10 series with primary attention to iASD. Cases involving TS access included electrophysiology ablation procedures, atrial appendage closure, and percutaneous balloon mitral valvuloplasty. Immediate postprocedural incidence of iASD was as high as 87%, with decreased incidence of residual iASD detected over time. At 18 months of follow-up, up to 15% of iASD cases persisted. Residual iASDs were not associated with clinical sequelae of embolism, cyanosis, or right heart failure.

iASDs are frequent following TS access and a majority resolve over time. Available evidence suggests iASDs are well tolerated but late term follow-up is limited. With the increased utilization of TS transcatheter procedures, the frequency and size of iASDs may rise. Understanding the rare but serious clinical implications of iASD and the need for systematic surveillance in the future is warranted.