A rate-responsive duty-cycling protocol for leadless pacemaker synchronization.

Area of Science:

• Biomedical Engineering
• Medical Devices
• Cardiovascular Technology

Background:

• Dual-chamber leadless pacemakers (LLPMs) utilize two implants for cardiac rhythm management.
• Inter-device communication in LLPMs is crucial for atrioventricular (AV) synchrony but significantly impacts battery longevity, reducing it by 35-45%.

Purpose of the Study:

• To analyze the power-saving potential of a novel LLPM synchronization protocol.
• To evaluate the impact of this protocol on maintaining AV synchrony.
• To optimize parameters for maximizing the trade-off between power consumption and AV synchrony.

Main Methods:

• System-level simulations were employed to optimize a novel window scheduling algorithm for LLPM synchronization.
• Key parameters optimized included the number of communication windows per cardiac cycle and averaging cycles for window updates.
• LLPM model sensing inputs were derived from human ECG recordings (MIT-BIH Arrhythmia Database); transceiver current consumption was estimated using microchip measurements.

Main Results:

• The optimized protocol achieved a median transceiver current consumption of 166 nA with a median AV synchrony of 92.5%.
• Compared to a non-rate-responsive approach prioritizing AV synchrony, this resulted in an 18.3% reduction in current consumption and a 3.2% decrease in AV synchrony.
• Maximizing the performance ratio (AV synchrony / current consumption) was achieved with one window per cardiac cycle and three averaging cycles.

Conclusions:

• Adopting a rate-responsive communication protocol for dual-chamber LLPMs can significantly enhance device longevity.
• This approach effectively balances power consumption and AV synchrony, potentially reducing the need for frequent device replacements.
• The findings suggest a viable strategy for improving the long-term performance of leadless pacemaker technology.