title: Heart rate variability in children with aortic valve stenosis - a pilot study.
abstract: BACKGROUND
  The aim of our prospective study was to evaluate heart rate variability (HRV) in children with aortic valve stenosis (AS) and its relationship with left ventricular mass and peak transaortic valve pressure gradient (PG).
  
  
  METHODS
  Sixty children with AS divided into 3 groups according to their PG and 60 healthy controls were studied. Holter ECG monitoring with time domain HRV analysis was performed. Left ventricular mass was calculated by echocardiography.
  
  
  RESULTS
  Mean values of all HRV parameters were statistically significantly lower (p < 0.001) in children with AS than in controls (respectively: SDNN 127.8 ±28.2 ms; 162.6 ±38.0 ms, SDNN day 99.7 ±26.6 ms; 134.1 ±36.1 ms, SDNN night 99.9 ±32.8 ms; 123.4 ±45.7 ms, SDANN 112.2 ±27.7 ms; 142.4 ±34.6, SDNNi 62.2 ±16.2 ms; 75.9 ±21.6, RMSSD 39.6 ±12.1 ms; 50.3 ±16.7 ms, rMSSD day 33.6 ±10.9 ms; 43.1 ±14.7 ms, rMSSD night 49.8 ±18.1 ms; 64.4 ±24.9 ms, pNN50 16.4 ±9.5%; 23.5 ±11.7%, pNN50 day 12.0 ±8.5%; 18.4 ±10.7%, pNN50 night; 26.5 ±14.8%; 36.4 ±17.4%. No significant differences between the mean values of HRV parameters in children with different PG and with and without myocardial hypertrophy were found. In children with AS and ventricular arrhythmia SDNN day was significantly lower (p < 0.05) compared to patients without arrhythmia (94.9 ±22.1 ms vs. 109.3 ±22.5 ms).
  
  
  CONCLUSIONS
  In children with AS the balance of the autonomic nervous systemic disturbed which manifests in an increase in sympathetic and decrease in parasympathetic activity. Transaortic valve pressure gradient and myocardial hypertrophy do not influence the HRV. The SDNN reduction during the day period may indicate the risk of ventricular arrhythmia in children with AS.
authors.affiliation: Medical University of Warsaw, Poland.
authors.forename: Bozena
authors.initials: B
authors.lastname: Werner
authors.forename: Anna
authors.initials: A
authors.lastname: Piorecka-Makula
authors.forename: Waldemar
authors.initials: W
authors.lastname: Bobkowski
keywords: aortic stenosis; children; heart rate variability