Value of CT localization of the fossa ovalis prior to transseptal left heart catheterization for left atrial ablation

AIMS: Transseptal puncture (TP) can be a difficult procedure and is not without risk of complications. The purpose of this study was to evaluate the use of three-dimensional multi-detector row computed tomography (MDCT) to localize the fossa ovalis (FO) and facilitate TP in patients undergoing left atrial catheter ablation. METHODS AND RESULTS: Fourteen consecutive patients were studied. Thirteen patients underwent pulmonary vein isolation and one patient had ablation for left atrial flutter. All patients underwent cardiac MDCT imaging pre-ablation for use in conjunction with electroanatomic mapping. Prior to puncturing the interatrial septum, standard fluoroscopic views of the transseptal sheath were compared with corresponding MDCT images tagging the FO. Successful, uncomplicated TP was achieved in all 14 patients. The mean duration of TP was 15.6 +/- 10.0 min. The average fluoroscopy time was 8.5 +/- 7.4 min. The MDCT images were deemed helpful in facilitating TP in 13 patients (93%). CONCLUSION: This study demonstrates the feasibility of MDCT to localize the FO and aid TP. For patients undergoing left atrial ablation in whom MDCT imaging is undertaken pre-ablation, tagging the FO can be easily performed and is a novel tool for guiding transseptal catheterization without additional risk.