The Prevalence of and Predisposing Factors for Late Atrial Arrhythmias after Transcatheter Closure of Secundum Atrial Septal Defects in Children.

Abstract

A 24 h Holter study in children after transcatheter secundum ASD (ASD II) closure was conducted to detect the prevalence of defects and/or device-related late atrial arrhythmias (LAAs). ASD II closure with an Amplatzer septal occluder (ASO) is an established procedure. Little is known about LAAs after device implantation. The eligible participants were children who had undergone ASO implantation, with a follow-up of ≥5 years, as well as one pre- and at least one post-procedural Holter ECG. In total, 161 patients (mean age: 6.2 ± 4.3 years), with a mean follow-up of 12.9 ± 3.1 years (range 5-19), were included. A median of four Holter ECGs per patient were available. LAAs occurred before intervention in four patients (2.5%), and it was peri-interventional in four patients (2.5%), sustained in three patients (1.9%), and developed in three patients (1.9%). In patients with pre- and peri-interventional LAAs, the Qp/Qs ratio was higher (6.4 ± 3.9 vs. non-AA: 2.0 ± 1.1 (p = 0.002)) and the IAS/ASO ratio was lower (1.18 ± 0.27 vs. non-AA: 1.7 ± 0.4 (p < 0.001)). The patients with LAAs differed from those without LAAs in their Qp/Qs (6.8 ± 3.5 vs. 2.0 ± 1.3; p < 0.0001) and IAS/ASO ratios (1.14 ± 0.19 vs. 1.73 ± 0.45; p < 0.001). The patients with LAAs had a Qp/Qs ratio ≥2.94:1, and those who developed LAAs had an IAS/ASO ratio <1.15. LAAs occurred in 1.9% of patients and were sustained in another 1.9% of patients but persisted in those with large shunt defects and large occluders in relation to the atrial septal length. The predisposing factors for LAAs after ASD closure were a high Qp/Qs ratio, pre-existing atrial arrhythmias, and a low IAS/ASO ratio.