Advanced pacing algorithms resembling device malfunction: A comprehensive review

Postatrial pacing ventricular refractory period, RYTHMIQTM and ventricular tachycardia response: “An Algorithmic Conflict”

“…This phenomenon was followed by 32 paced events before AV search was activated again. 2 Furthermore, the…”

“…However, the frequent PVCs, often falling in the post atrial pacing ventricular refractory period favored a paced event after the PVCs, reverting to the programmed AVI delay when ≥2/10 events were paced. This phenomenon was followed by 32 paced events before AV search was activated again 2 . Furthermore, the absence of ventricular safety pacing in Boston devices could lead to pacing on the T wave after PVC.…”

“…A slow beat is defined as a ventricular paced or ventricular sensed event that is at least 150 ms slower than the AAI(R) pacing rate. Slow ventricular beats are any of the following: (1) ventricular paced event; (2) ventricular sensed event >AAI lower rate limit + 150 ms; (3) ventricular sensed event >AAI(R) sensor indicated rate + 150 ms. After the device has switched to DDD(R) mode following three slow beats, AV search+ TM promotes intrinsic ventricular activation by periodically extending the AV delay. The search begins every 32-1024 ventricular cycles (programmed search interval): when the AV Search Interval is reached, the AV delay is extended to the programmed AV search + value.…”