Clinical, Hemodynamic, and Intracardiac Echocardiographic Characteristics of Secundum Atrial Septal Defects‐Related Paradoxical Embolism in Adulthood

BACKGROUND: Paradoxical embolism associated with secundum atrial septal defect (sASD) is a relatively rare but well-known occurrence. The purpose of our study is to report the clinical, hemodynamic, and anatomical features assessed by intracardiac echocardiography (ICE) of sASD as related to paradoxical embolism. METHODS: Five hundred thirty-seven patients (mean age 48 ± 19.0 years) admitted for transcatheter repair of interatrial shunts were enrolled in a prospective registry over a 10-year period (September 2003-September 2013). All patients underwent transesophageal echocardiography, complete right and left catheterization, prior to the device-based procedure. ICE was performed in all patients in order to investigate the interatrial septum anatomy and to monitor device implantation. These results were compared with the data of patients with patent foramen ovale (PFO) patients and nonemboligenous sASD admitted at the same time period. RESULTS: Twenty-four patients (6.2%) out of 386 who underwent transcatheter repair for paradoxical embolism had a secundum ASD. The defects were cribrosus in 41.6% (10/24). All single sASD (58.3%) had a peculiar anatomical feature a so-called flat elliptical shape with a major axis of 7.6 ± 2.4 and minimal axis of 2.5 ± 1.6 mm. Patients with sASD-related paradoxical embolism had a higher frequency of deep venous thrombosis compared to PFO patients. In comparison to nonemboligenous sASD, such patients had lower mean pulmonary pressure and smaller defects. CONCLUSION: sASD related to paradoxical embolism had peculiar clinical, hemodynamic, and anatomical characteristics, which classified such defects in the middle of the spectrum between nonemboligenous secundum ASD and PFO.