Management of Iatrogenic Atrial Septal Defects in the Era of Large-Bore Transcatheter Mitral Valve Therapies

Iatrogenic atrial septal defect after catheter ablation—to close or not to close?

“…Most of the iatrogenic atrial septal defects (iASDs) close spontaneously, and for those that persist, the majority do not result in clinical manifestations. 1 Infrequently, a clinically significant interatrial shunt persists; mostly left to right, resulting in right heart failure. 2 We report an unusual case of arterial desaturation due to right-to-left interatrial shunting following transseptal access for electrophysiological ablation, which was successfully treated with device closure.Case report.…”

“…In most patients, the iASDs created close spontaneously or remain asymptomatic. 1 Significant residual shunts usually occur after use of large bore devices such as with percutaneous mitral valve repair. It has been shown that up to 50% of patients have a residual iASD 6 months after transseptal access (22-French size sheath) for TMVr with the MitraClip system (Abbott Vascular, Redwood City, US).…”

“…3 Persistent iASDs after transseptal access with smaller catheters such as electrophysiological procedures, BMV and LAAC are less common. 1 Specifically, AF ablation requires 2 catheters in the left atrium (LA), achieved using either a single transseptal puncture with double cannulation, or a double transseptal puncture. Both are accepted techniques, but the single puncture technique demonstrated a slightly higher incidence of persistent iASDs, although the overall rate was low.…”

“…Less commonly, right-to-left shunts result in arterial desaturation. 1,2,9 Risk factors that predispose to persistent iASD include larger transseptal sheath size, procedure duration, amount of catheter manipulation while across the interatrial septum, lower LVEF, larger right atrial size, more severe MR and TR, as well as higher pulmonary artery, left and right atrial pressures. 1,3,9 It has also been demonstrated that all defects <4mm closed and all defects >8mm persisted at 30 days post-procedure.…”

“…1,2,9 Risk factors that predispose to persistent iASD include larger transseptal sheath size, procedure duration, amount of catheter manipulation while across the interatrial septum, lower LVEF, larger right atrial size, more severe MR and TR, as well as higher pulmonary artery, left and right atrial pressures. 1,3,9 It has also been demonstrated that all defects <4mm closed and all defects >8mm persisted at 30 days post-procedure. 10 Since most iASDs are benign or close spontaneously, and as there are risks associated with percutaneous closure (device erosion, device embolisation, device clot formation and difficulty in performing future transseptal procedures), 2 routine closure is currently not recommended.…”