Optimizing atrial sensing parameters in leadless pacemakers: Atrioventricular synchrony achievement in the real world

Real‐life ambulatory performance of leadless AV synchronous pacemakers—Are all questions answered?

“…Ambulatory AVS in AccelAV was assessed using 24h‐Holter ECGs in patients with complete AV block and found to be in a very similar range (~75%). In consecutively included LLPM patients showing a higher rate of intact AV conduction, outpatient AVS even reached almost 90% 5 . Atrial tracking at lower sinus rates at rest seems to be relatively robust in particular.…”

“…Intermittent oversensing of mechanical signals that are unrelated to the atrial mechanical contraction (e.g., induced by physical activity or A3 oversensing) would also result in AM‐VP sequences and imply AVS. Indeed, Briongos‐Figuero et al 5 also found a positive correlation between AVS determined by Holter‐ECG and the LLPM device counters, but the correlation coefficient was only moderate (ICC 0.52). Thus, important questions remain and further studies are required, which validate the reliability of the device counters in a real‐life outpatient setting against long‐term surface ECG data.…”

“…However, the results provided in the study by Garweg et al, Neugebauer et al, and in AccelAV have a crucial finding in common: appropriate atrial tracking at sinus rates ≥80‐100 beats per minute is often challenging to achieve 4,6 . Device optimization after a run‐in phase is paramount and significantly improves AVS 4–6 . The A3 window end (time and maximum) and A4 threshold (threshold and minimum) have a significant impact on AVS when analyzed in multivariate models 4,5 .…”

“…In consecutively included LLPM patients showing a higher rate of intact AV conduction, outpatient AVS even reached almost 90%. 5 Atrial tracking at lower sinus rates at rest seems to be relatively robust in particular. However, the results provided in the study by Garweg et al, Neugebauer et al, and in AccelAV have a crucial finding in common: appropriate atrial tracking at sinus rates ≥80-100 beats per minute is often challenging to achieve.…”

“…4,6 Device optimization after a run-in phase is paramount and significantly improves AVS. [4][5][6] The A3 window end (time and maximum) and A4 threshold (threshold and minimum) have a significant impact on AVS when analyzed in multivariate models. 4,5 Unsurprisingly, the general programming recommendations for an appropriate A3 threshold have changed recently as well.…”