Heart rate variability parameters in children with ventricular preexcitation.

IntroductionThe autonomic nervous system has a regulatory effect on cardiac electrophysiology and arrhythmogenesis. We aimed to assess cardiac autonomic status using heart rate variability (HRV) parameters in children with ventricular preexcitation. MethodsThe electrocardiography, Holter monitoring, transesophageal electrophysiological study (TEEPS), and invasive electrophysiological study (EPS) results of ventricular preexcitation patients obtained over a 7-year period in our clinic were evaluated. According to the TEEPS results, patients' accessory pathway conduction was classified as adverse (n = 40) or nonadverse (n = 25). The HRV parameters of patients were compared according to tachycardia inducibility that assessed by TEEPS and EPS. Also, HRV parameters were compared in patients with adverse and nonadverse pathway conduction. Further, the HRV parameters of preexcitation patients were compared with those of healthy controls. ResultsLF/HF, the best measure of sympathovagal balance, was statistically higher in patients with adverse conduction than in patients without adverse conduction and controls (P=0.001). The LF/HF ratio was higher in ventricular preexcitation patients with inducible tachycardia than those without in EPS (P=0.001). In addition, the LF/HF ratio was higher in symptomatic ventricular preexcitation patients than asymptomatic ones (P=0.001). No difference in HRV parameters was found between preexcitation patients and controls. ConclusionAutonomic tonus in patients with ventricular preexcitation may affect accessory pathway conduction properties, tachycardia inducibility, and symptomology. The indicator of sympathovagal balance, LF/HF ratio, increased in ventricular preexcitation patients with inducible tachycardia and those that were symptomatic.