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Heart rate variability effect on the myocyte action potential duration restitution: insights from switched systems

Hila Dvir1, Sharon Zlochiver

  • 1Department of Biomedical Engineering, Tel Aviv University, Ramat Aviv, Tel Aviv 69978, Israel. dvirhila@post.tau.ac.il

Annual International Conference of the IEEE Engineering in Medicine and Biology Society. IEEE Engineering in Medicine and Biology Society. Annual International Conference
|January 19, 2012
PubMed

Insights

Heart rate variability (HRV) stabilizes atrial myocyte action potential duration (APD) restitution. Introducing HRV to computer models decreased extra beat APD, suggesting potential applications in artificial pacemakers to reduce arrhythmia susceptibility.

Area of Science:

  • Computational biology
  • Cardiac electrophysiology
  • Systems theory

Background:

  • Physiological heart rate exhibits stochastic behavior known as heart rate variability (HRV).
  • Heart rate variability influences cardiac electrical activity, specifically the action potential duration (APD) of atrial myocytes.
  • Understanding HRV's impact on APD is crucial for cardiac modeling and therapeutic interventions.

Purpose of the Study:

  • To analyze the influence of heart rate variability (HRV) on the action potential duration (APD) of atrial myocytes using a computer model.
  • To investigate the theoretical underpinnings of HRV's effect on APD restitution.
  • To explore potential applications of HRV modulation in artificial pacemakers.

Main Methods:

  • Development and utilization of a computer model simulating atrial myocyte action potentials.
  • Application of an S1-S2 pacing protocol to assess APD changes under varying heart rate conditions.
  • Theoretical analysis using switched systems theory to explain observed phenomena.

Main Results:

  • Introduction of HRV into the myocyte model decreased the APD of the extra beat (S2) compared to a constant heart rate.
  • A theoretical framework based on switched systems theory suggests HRV stabilizes APD restitution by randomizing transitions between action potential phases.
  • Low HRV was associated with reduced system stability, potentially increasing susceptibility to arrhythmias.

Conclusions:

  • HRV exerts a stabilizing effect on atrial myocyte APD restitution, potentially through mechanisms described by switched systems theory.
  • Conditions with low HRV may exhibit reduced cardiac system stability.
  • Artificial pacemakers could potentially incorporate modulated HRV to decrease arrhythmia susceptibility.

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