Question
Is it possible to stop nocturnal non‑capture in an Aveir VR leadless pacemaker (LP) without modifying the output voltage?
Short answer
Sometimes, yes. Night‑time non‑capture can often be reduced (or eliminated) without increasing the voltage amplitude by addressing physiologic drivers of threshold rise and by using programming changes that don’t touch amplitude.
What to adjust that isn’t voltage
- Increase pulse width. Lengthening the pulse width lowers the effective capture threshold at the same voltage (chronaxie/rheobase relationship).
- Raise the nighttime lower rate (or disable sleep‑rate lowering). Very slow rates can unmask non‑capture.
- Review Aveir VR safety margins & timing features in the Merlin programmer and base margins on the highest measured threshold.
- Correct reversible physiologic causes (K⁺/Mg²⁺ shifts, hypoxemia/OSA, drug effects) that worsen at night.
- Consider early post‑implant threshold drift and re‑measure before altering amplitude.
Practical programming sequence (no amplitude change)
- Recheck a nighttime threshold (or simulate with slow rates) and lengthen pulse width.
- Raise the lower rate during sleeping hours; avoid aggressive hysteresis.
- Review medications; check K⁺/Mg²⁺; screen for sleep apnea / nocturnal hypoxemia.
- Program a conservative margin based on the highest observed threshold, not daytime values alone.
Tip: Share your interrogation values and we’ll suggest concrete pulse‑width and rate settings.