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Published on: February 22, 2018
An approach to measure atrial and ventricular heart rate variability using pacemaker-mediated intracardiac
Andreas Schuchert1, Stefan M Wagner, Thomas Meinertz
1Medical Clinic III, University-Hospital Hamburg-Eppendorf, Hamburg, Germany. schuchert@uke.uni-hamburg.de
Insights
This study introduces a new method for measuring atrial and ventricular heart rate variability (HRV) using pacemaker data. The findings suggest that ventricular HRV may not always reflect sinus node activity changes.
Area of Science:
- Cardiology
- Biomedical Engineering
- Physiology
Background:
- Traditional heart rate variability (HRV) analysis relies on ventricular intervals due to challenges in precisely locating P waves on surface ECGs.
- Accurate assessment of atrial activity is crucial for a comprehensive understanding of cardiac autonomic function.
Purpose of the Study:
- To describe and validate a novel approach for determining both atrial and ventricular HRV using intracardiac electrograms obtained from pacemaker data.
- To compare atrial and ventricular HRV parameters in patients with dual-chamber pacemakers.
Main Methods:
- Utilized intracardiac electrograms from 12 patients with dual-chamber pacemakers (Logos) during sinus rhythm.
- Recorded high-resolution electrograms via the pacemaker's telemetry channel.
- Calculated standard deviation of NN intervals (SDNN), root mean square of successive differences (RMSSD), and percentage of successive differences >50 ms (pNN50) for both atrial and ventricular intervals.
Main Results:
- Analyzed 15,504 heart cycles with minimal need for manual correction (0.9%).
- Found minimal overall differences between atrial and ventricular HRV indices (pNN50: -0.5%±2.1%; SDNN: 0.4±2.1 ms; RMSSD: -0.1±3.5 ms).
- Observed that ventricular HRV did not consistently reflect sinus node activity changes in all patients, particularly noted in pNN50 analysis.
Conclusions:
- Demonstrated the feasibility of a new method to assess atrial and ventricular HRV from pacemaker-mediated intracardiac electrograms.
- Highlighted potential discrepancies where ventricular HRV may not fully represent atrial electrical activity or sinus node function.
- Suggests this method offers a valuable tool for comprehensive cardiac autonomic assessment in pacemaker patients.
Abstract:
Heart rate variability (HRV) measurements are usually performed from ventricular beat-to-beat intervals because of the difficulty to precisely locate the P wave fiducial point in surface ECG recordings. The aim of the study was to describe an approach to determine the atrial and ventricular HRV using pacemaker-mediated intracardiac electrograms. Twelve patients with the dual chamber pacemaker Logos were included. The atrial and ventricular intracardiac electrograms were transmitted with the high resolution telemetry channel of the pacemaker to an external recorder for 20 minutes while the patients were supine. During the measurements the patients were in sinus rhythm with intrinsic AV conduction. After computer assisted triggering of the atrial and ventricular events, the resultant intervals were used to calculate the standard deviation of all NN intervals (SDNN), the square root of the mean squared differences of successive NN intervals (RMSSD), and the percentage of successive interval differences >50 ms (pNN50). The differences between atrial and ventricular HRV-Indexes were assessed for each patient with a cut-off point of 1%. Differences >1% were analyzed in detail. A total of 15,504 heart cycles were analyzed. A manual correction due to false or not triggered atrial or ventricular events was necessary in 0.9%. The overall difference between atrial and ventricular pNN50 was-0.5%+/-2.1%and differences >1% were observed in 4 patients. The NN50 events occurred in the atrial as well as in the related ventricular interval in 84%. NN50 events occurred only in the atrium in 6% and only in the ventricle in 10%. The mean differences between atrial and ventricular SDNN and RMSSD were 0.4+/-2.1 ms and-0.1+/-3.5 ms with intra-individual differences <1%. The present study described a new method and demonstrated its feasibility to determine atrial as well as ventricular HRV from pacemakermediated intracardiac electrograms. The differences for pNN50 indicate that ventricular HRV did not reflect the changes of sinus node activity in all patients.
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