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User question:
Does a Leadless Pacemaker Consume Battery When Heart Rate is 80 bpm?
Answer: No, a leadless pacemaker set at 50 bpm typically does not consume battery when the heart’s natural rhythm is above 50 bpm — such as 80 bpm — because it is not pacing.
How It Works:
The device is set in VVI mode (common for leadless devices like Aveir VR).
It only paces when the natural heart rate drops below the set rate (50 bpm).
If the heart beats at 80 bpm, the pacemaker remains inactive.
Since no pacing pulse is delivered, battery usage is minimal—limited to sensing and telemetry.
Conclusion: When the intrinsic heart rate stays at or above 50 bpm, the device primarily monitors, preserving battery.
Main Contributors to Battery Drain in Leadless Pacemakers
Pacing Burden: More pacing = faster battery drain. Less pacing = longer battery life.
Output Voltage and Pulse Width: Higher voltage and wider pulse width consume more energy per beat.
Heart Rate Setting: Higher settings increase pacing, even if the heart could beat on its own.
Impedance: Low impedance requires more current. Fibrosis can increase impedance over time, potentially reducing drain.
Sensing and Telemetry: These consume minimal energy compared to pacing output.
Summary Table: Battery Drain Drivers
Factor
Effect on Battery
Pacing frequency
Major — most direct effect
Output voltage
Major — higher voltage = faster drain
Pulse width
Moderate — longer pulse = more energy
Heart rate setting
Moderate — higher rate = more pacing
Impedance
Variable — depends on tissue response
Sensing/telemetry
Minor — low impact overall
Battery Life Estimation Example
Assumptions:
Device: Abbott Aveir VR
Pacing burden: 40%
Output voltage: 3.5 V
Pulse width: 0.4 ms
Rate setting: 50 bpm
Impedance: 600 ohms
Battery capacity: ~1000–1100 mAh (~250–300 J energy)
Energy Per Pulse:
E = (V² × PW) / R
= (3.5² × 0.0004) / 600
= 0.0000049 joules per pulse
At 40% pacing of 50 bpm (28,800 pulses/day):
Daily energy = 28,800 × 0.0000049 ≈ 0.141 J/day
Over 4.5 years ≈ 0.141 × 1642 = 231.6 J
This fits well within the battery’s energy capacity.
Estimated Battery Life: ~4.5 years
How It Changes:
100% pacing at 3.5V: battery life drops to ~2.5–3 years
Low pacing (<10%): battery life could extend to 7–8+ years
Lowering output to 2.5V: may extend battery life by 1–2 years