P925Cardiac autonomic dysfuntion in adult patient with uncorrected atrial septal defect : a role of pulmonary arterial hypertension

Abstract

Abstract Background Atrial Septal Defect (ASD) is a congenital heart disease that often under-diagnosed in youth. Atrial septal defect has a poor clinical manifestation at Pulmonary Arterial Hypertension (PAH) condition. Cardiac autonomic dysfunction may occur in PAH due to over sympathetic activation. This condition in general population is associated with increase risk of sudden cardiac death. Despite the case, there are only limited studies which associated cardiac autonomic dysfunction and PAH in adult patient with uncorrected ASD. Purpose This study aims to compare cardiac autonomic dysfunction, using heart rate variability, in adult patient with uncorrected ASD between PAH and non-PAH group. Methods Adult (18+) patient with uncorrected ASD who listed in ASD registry in Indonesia, were selected in this analytical observational study. Patients in whom no other congenital defect and atrial fibrillation in electrocardiogram were eligible for inclusion. Diagnose of PAH was established when mean pulmonary arterial pressure value from right heart catheterization is ≥ 25 mmHg. Arrhythmias and heart rate variability, using Standard Deviation of Normal-Normal (SDNN), High Frequency (HF) and Low Frequency (LF) parameters, were collected from holter monitoring. These procedures were performed on the same day. Results We enrolled 55 adult patients with uncorrected ASD (mean age: 33.3 ± 10.3 years, 89.1% women), consist of 51 secundum ASD, 3 sinus venosus ASD and 1 primum and secundum ASD patient. They were divided into PAH group (28 patients) and non-PAH group (27 patients). Patients in PAH group had a higher incidence of paroxysmal atrial fibrillation and ventricular extrasystole compare to those in non-PAH group (28.5% vs. 14.8% and 75% vs. 70%). All parameters of heart rate variability was significantly reduced in PAH group compare to non-PAH group (SDNN : mean difference 14.5 ± 2.98 ms, CI 95%, P < 0.001; HF : median difference 99.5 ms2, P < 0.001; LF : median difference 129.6 ms2, P < 0.001). Conclusion A marked reduction in cardiac autonomic function occur in adult uncorrected ASD patient with PAH compare to patient with non-PAH, that might be the result of decreasing baroreceptor and increasing chemoreceptor function in PAH.