Analysis of maximum P-wave duration and dispersion after percutaneous closure of atrial septal defects: Comparison of two septal occluders

OBJECTIVE: Amplatzer septal occluder (ASO) is the most widely used device for closure of atrial septal defect (ASD). Figulla septal occluder (FSO) is a similar device to ASO with some structural innovations. The aim of study is to assess the maximum P-wave duration (Pmax) and dispersion (Pd) in patients who underwent ASD closure with both devices, to determine the effects of structural innovations on atrial electrical inhomogeneity. METHODS: The study is a retrospective cohort analysis. Between December 2005 and March 2010, 121 patients underwent percutaneous closure of secundum ASD were included in this study. FSO was used in 79 patients, ASO in 42 patients. Pmax and Pd were measured on the surface electrocardiography before and soon after procedure. For comparison of P-wave parameters initially and after procedure paired t-test was used. Correlation analysis was performed using Pearson correlation test. RESULTS: Pmax and Pd were significantly increased immediate after procedure (p<0.001). In FSO and ASO group pre/postprocedural Pd were 38.3 ± 2.7/ 44.1 ± 2.7 msec and 37.5 ± 2.5/ 50.1 ± 2.2 msec respectively. ASO group had a greater postprocedural Pmax and Pd (p<0.001). Left and right atrial disc diameter and device size were the strongest correlates of Pd (r=0.52, p<0.001; r=0.58, p<0.001; r=0.35, p=0.001, respectively). Moderate correlation was found between pre-intervention Pd and age (p=0.008). CONCLUSIONS: Pmax and Pd were significantly increased soon after atrial septal defect closure procedure in both devices. Pd is significantly lower in patients closed with FSO device. Difference may be due to the distinctive texture of devices. There was no significant difference in terms of clinically apparent arrhythmia after closure with both device types.