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Updated: Mar 6, 2026
Author Spotlight: Investigating HR-Dependent Cardiac Function in Mouse Models Through a Novel Atrial-Pacing Approach
Published on: July 21, 2023
Pro-arrhythmic effect of heart rate variability during periodic pacing
Insights
High ventricular heart rate variability (HRV) is linked to healthy hearts, while low HRV may indicate arrhythmias. This study found that incorporating HRV into pacing can promote cardiac alternans, potentially leading to arrhythmias.
Area of Science:
- Cardiovascular Physiology
- Cardiac Electrophysiology
- Biomedical Engineering
Background:
- Healthy hearts exhibit high ventricular heart rate variability (HRV), whereas diseased hearts show low HRV, suggesting low HRV as a marker for cardiac arrhythmias.
- There is growing interest in using HRV in cardiac pacing to mimic healthy heart function and stabilize electrical activity in diseased hearts.
Purpose of the Study:
- To validate numerical findings on the pro-arrhythmic effects of HRV-incorporated pacing using experimental models.
- To investigate the impact of HRV-based pacing on cardiac alternans and arrhythmia development in whole hearts.
Main Methods:
- High-resolution optical mapping experiments were conducted on Langendorff-perfused healthy whole mouse hearts.
- The study validated previous numerical simulations demonstrating the effects of HRV in pacing.
Main Results:
- Experimental results confirmed that incorporating HRV into periodic pacing promotes the onset of cardiac alternans.
- Cardiac alternans are considered a precursor to potentially fatal cardiac rhythms.
Conclusions:
- Incorporating HRV into cardiac pacing, despite addressing clinical needs, may pose risks due to its pro-arrhythmic potential.
- Further research is crucial to understand paced cardiac dynamics and develop safer, anti-arrhythmic pacing strategies.
Abstract:
Clinically, healthy hearts have been associated with a high ventricular heart rate variability (HRV) while diseased hearts have been known to exhibit low ventricular HRV. Hence, low HRV is suggested to be a marker of cardiac ventricular arrhythmias. Over the past few years, there has been considerable amount of interest in incorporating HRV in pacing to emulate healthy heart conditions and re-stabilize the electrical activity in diseased hearts. Recently, we used single cell numerical simulations to demonstrate that HRV incorporated into periodic pacing promotes alternans formation and thus, can be pro-arrhythmic. Here, we performed high-resolution optical mapping experiments on Langendorff perfused, healthy whole mice hearts to validate our numerical findings. Our results indeed demonstrate that HRV promoted the onset of cardiac alternans, which is believed to be a precursor of fatal cardiac rhythms. Hence, our present study suggests that incorporating HRV into periodic pacing while addressing several clinical needs may not be safe. There is a pressing need to better understand paced cardiac dynamics and develop anti-arrhythmic pacing techniques that would prevent cardiac arrhythmias.
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