B-po04-209 achieving optimal ambulatory performance with an av synchronous leadless pacemaker during high sinus rates: a case report

Micra™ AV is a leadless VDD pacemaker which utilizes an accelerometer to detect atrial contractions and provide AV synchronous pacing. Achieving high AV synchrony (AVS) becomes more challenging at higher sinus rates, when passive ventricular and active atrial filling occur simultaneously. Thus, programming complexity increases. To provide a successful programming strategy for achieving high AVS at higher sinus rates and during ambulatory operation. NA The AccelAV post-market trial utilizes a Holter to collect device markers and accelerometer/EGM waveform signals from the Micra AV along with surface ECG. AVS is assessed by blinded p-wave truthing of the recordings at multiple timepoints including after implant, at 1 month during rest and continuing for 24 hours, and at 3 months. Device programming as needed for optimal AVS is performed at follow-up visits. A 91-year old female presented to the emergency room with sinus tachycardia (110 bpm) and complete AVB and was subsequently implanted with a Micra AV leadless pacemaker. Immediately after implant, following the VDD auto setup period, AVS was 60%. Manual programming changes included the following: a fixed A3 threshold at 2.8 m/s2 to allow for sensing of summated A7 signal in the A3 window, PVARP to 550 ms, and Smoothing Delta to 50 ms. The subject remained in complete AVB at the 1 month visit. AVS was 94.0 % at rest and 93.6% during the 24 hour ambulatory period with AVS observed up to 100 bpm (Figure). AV conduction was present at the 3 month visit. Patients with high sinus rates can achieve high levels of AV synchrony, although clinician programming may be needed for optimal performance.