Abstract
Atrial transseptal puncture is a fundamental maneuver in electrophysiological intervention, and atrial septal aneurysm (ASA) is a common cause of failure of transseptal puncture. We report a rare case of ASA in a patient with atrial fibrillation in which the conventional transseptal puncture method failed despite the guidance of intracardiac ultrasound and was completed by a novel atrial septal puncture guidewire, and double septal puncture was completed. Giant ASA is rare and is 1 of the major causes of unsuccessful atrial septal puncture, even under the guidance of intracardiac echocardiography. The new Accusafe guidewire (Synaptic Medical) should be the initial selection of transseptal puncture rather than a conventional transseptal puncture tool when encountering similar anatomic abnormalities of the atrial septum.