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Sinus node dysfunction in patients with Fontan circulation: could heart rate variability be a predictor for pacemaker

Jenny Alenius Dahlqvist1, Urban Wiklund2, Marcus Karlsson2

  • 1Department of Clinical Sciences, Pediatrics, Umeå University, 901 85, Umeå, Sweden. jenny.alenius@umu.se.

Pediatric Cardiology
|March 29, 2019
PubMed

Insights

Heart rate variability (HRV) is higher in Fontan patients with sinus node dysfunction (SND). Severe SND requiring pacemakers may show reduced diurnal HRV, suggesting HRV analysis can aid Fontan patient follow-up.

Area of Science:

  • Cardiology
  • Pediatric Cardiology
  • Autonomic Nervous System Function

Background:

  • Sinus node dysfunction (SND) is a significant cause of morbidity in patients following Fontan surgery.
  • Heart rate variability (HRV) quantifies autonomic regulation of the heart and is linked to SND in adults.
  • Understanding HRV changes in Fontan patients with SND is crucial for monitoring and management.

Purpose of the Study:

  • To investigate if 24-hour electrocardiographic (ECG) recordings can detect changes in HRV in Fontan patients with SND.
  • To compare HRV parameters between Fontan patients with and without SND, and with healthy controls.

Main Methods:

  • Compared HRV from 24-h ECG recordings in four groups: Fontan patients with SND requiring pacemakers (n=12), Fontan patients with SND without pacemaker indication (n=11), Fontan patients without SND (n=90), and healthy controls (n=66).
  • Analyzed HRV using the Poincaré plot index SD2 and the very low-frequency (VLF) component.

Main Results:

  • Both SND groups exhibited significantly higher SD2 and VLF HRV components compared to healthy controls and Fontan patients without SND.
  • Fontan patients with SND requiring pacemakers showed a trend towards reduced SD2 and VLF compared to those with SND but no pacemaker (p=0.06).
  • These findings suggest altered autonomic regulation in Fontan patients with SND.

Conclusions:

  • Fontan patients with SND demonstrate significantly altered HRV compared to controls.
  • A trend of reduced diurnal HRV in severe SND requiring pacemakers may indicate further autonomic compromise.
  • HRV analysis shows potential as a valuable tool for monitoring the development of SND in Fontan patients.

Keywords:
Congenital heart diseaseFontan circulationHeart rate variabilityPacemakerPoincaré analysisSinus node dysfunction

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