Vegetative state assessment in children with supraventricular arrhythmias before and after radiofrequency ablation

Aim: To assess erythrocyte membranes β-adrenoreactivity and heart rate variability (HRV) in children with supraventricular arrhythmias initially and in the early period after radiofrequency ablation (RFA).Study method. The study included 43 patients 13 [10; 15] years with supraventricular arrhythmias and indications for interventional treatment. The patients were divided into groups depending on the electrophysiological variant of the arrhythmias: manifest Wolf-Parkinson-White (WPW) phenomenon - 15 patients; latent and manifest WPW syndrome - 13 patients; atrioventricular nodal reentry tachycardia (AVNRT) - 10 patients; atrial ectopic tachycardia - 5 patients. The control group consisted of 11 practically healthy children 14 [12; 16] years. The patients underwent RFA. Initially and in 3-5 days after RFA, the following was performed: HRV time analysis according to Holter monitoring ECG; determination of erythrocyte membranes β-adrenoreactivity in blood samples.Results. In all groups, initially and in 3-5 days after RFA, the median level of erythrocyte membranes β-adrenoreactivity remained within the normal range; no statistically significant changes in the indicator were detected, including when compared with the control group. Analyzing HRV in patients with the WPW phenomenon and syndrome, pNN50 and rMSSD values decreased statistically significantly after RFA, p = 0.004, p = 0.047, respectively. In patients with AVNRT, the level of SDANNi increased statistically significantly, p = 0.007. The changes indicate a decrease in the influence of the vagus nerve and an increase in sympathetic influences, which is regarded as a decrease in HRV.Conclusion. Supraventricular arrhythmias in children with structurally normal hearts are not accompanied by dysfunction of the autonomic nervous system (ANS) according to the analysis of erythrocyte membranes β-adrenoreactivity and HRV, which indicates the absence of a significant contribution of the ANS to the pathogenesis of these arrhythmias. In the early postoperative period after RFA, a decrease in HRV was noted, associated with manifestations of operational stress. The lack of dynamics in the erythrocyte membranes β-adrenoreactivity level after RFA indicates that in this category of patients HRV indicators respond faster. The study results suggest the value of HRV assessment in patients with supraventricular arrhythmias, while the use of erythrocyte membranes β-adrenoreactivity is more promising in patients with ventricular arrhythmias in whom HRV analysis is limited.