Iatrogenic atrial septal defects after transseptal puncture for percutaneous left atrial appendage occlusion and their hemodynamic effects.

Background: Percutaneous left atrial appendage occlusion (LAAO) requires puncture of the interatrial septum. The immediate hemodynamic effects of iatrogenic atrial septal defects (iASD) after LAAO have not been examined so far. We aimed at evaluating these effects through invasive measurements of pressure and oxygen saturation. Moreover, we assessed the incidence of persistent iASD at three months. METHODS: Forty-eight patients scheduled for percutaneous LAAO were prospectively included in the study. Pressure and oxygen saturation were measured (1) in the right atrium (RA) before transseptal puncture, (2) in the left atrium (LA) through the transseptal sheath after transseptal puncture, (3) in the LA after removal of introducer sheath, and (4) in the RA after removal of introducer sheath. Transesophageal echocardiography was performed at three months to detect iASD. RESULTS: = 0.129). Follow-up transesophageal echocardiogram at 3 months revealed a persistent iASD in 4 patients (8.5 %). CONCLUSIONS: Our study suggests that iASD after percutaneous LAAO does not result in significant shunts directly after the procedure, although a significant increase of mean right atrial pressure can be observed. Persistent iASDs after percutaneous LAAO seem to be relatively rare at three months.