Heart Rate Variability and Atria Function in Children at Late Follow-Up Evaluation After Atrioventricular Node Slow-Pathway Radiofrequency Ablation

Abstract

This study was designed to assess the changes in the conductive system, autonomic dysfunction, and global and regional function of the atria and ventricles in children late after slow-pathway radiofrequency ablation (RFA). The study enrolled 22 children, who has successfully undergone RFA 2 to 5 years previously (RFA group) and 20 healthy children (control group). Electrophysiologic study was performed for the RFA group. Holter monitoring and echocardiography were performed for all the children. At a late follow-up assessment, the RFA children were free of paroxysms, whereas 8 of the 22 children (36%) reported transient palpitations. Both mean and maximal heart rates (HR) were significantly increased, whereas indices of HR variability (% of succesive normal sinus RR intervals exceeding 50 ms [pNN50], root mean square of the succesive normal sinus RR interval difference [rMSSD], high-frequency component [HFC]) were significantly decreased in the RFA group compared with preablation and control data. Left atrial (LA) and right atrial (RA) volumes were significantly higher, and atria deformation indices were significantly lower in the RFA group. Correlations were found between the mean HR and the volumes of LA (r = 0.477; p < 0.001) and RA (r = 0.512; p < 0.001). A negative correlation between the maximal LA volume and the longitudinal strain rate (SR) during relaxation (r = –0.476; p = 0.03) and a positive correlation between the minimal LA volume and both longitudinal SR (r = 0.361; p = 0.03) and strain (ε) (r = 0.375; p = 0.024) during contraction were shown. These data suggest a possible link between atrial dysfunction and the hyperadrenergic state after RFA.

The association between heart rate variability and biatrial phasic function in arterial hypertension

“…First, our results have shown that HRV parameters correlated with mitral and tricuspid E/e' ratio, surrogate parameters of LV and RV diastolic function, which could possibly explain the association between HRV and LA and RA conduit and booster function. Second, the relationship between heart rate and atrial volumes and strain/strain rates reported previously, 28 and the correlation between 24-hour heart rate and HRV variables in our population might elucidate the association among HRV and atrial phasic function. Third, LV and RV hypertrophy has an important impact on both HRV and atrial function, which could additionally explain the mutual relation between HRV and atria in our investigation.…”

“…Namely, Sileikiene et al found an association between heart rate and LA and RA volumes in pediatric population, as well as a correlation between atrial volumes and atrial strain and corresponding strain rates. 28 The authors did not investigate the eventual association between HRV parameters and atrial phasic function. However, Friedman reported a correlation between increasing LA dimensions and reduced HRV in patients with persistent atrial fibrillation.…”

The Relationship Between Heart Rate Variability Parameters and Atrioventricular Nodal Reentrant Tachycardia

“…The R-R intervals prior to ablation in children were longer than after ablation of the slow accessory AV pathway (1) . Furthermore, the 24-h Holter monitoring demonstrated that the mean and maximal HR were increased, whereas the HRV parameters were decreased after ablation of AV slow accessory pathway in children (17) . Interestingly, administration of isoproterenol after ablation to evaluate the slow accessory pathway and generate AV nodal echo beats led to no significant differences in the recurrence rates between patients with complete elimination of the slow pathway and patients with residual jump and/or single echo beat (18) .…”