Stratos LV/LV-T Technical Manual 77
In the case an atrial sense event falls within the PMT protection window, the Stratos CRT-Ps start a minimal ARP.
2.3.6.2Atrial Far-Field Protection
In all dual chamber modes with atrial sensing, the Stratos CRT-Ps start an atrial FFP window upon each ventricular event to prevent sensing of far-field potentials in the ventricle. The atrial far-field protection window is separately programmable for ventricular sensed events at 30…(10)…100…(1)…200 ms and for ventricular paced events at 30…(10)…100 and 100…(10)…220 ms. If an atrial event occurs during the FFP window, the atrial event is classified as an invalid FFP event and has no influence on the timing of the CRT-P.
With ventricular events (right ventricular sensed or paced, left ventricular paced, VES), the Stratos CRT-Ps start an FFP interval.
2.3.7 Atrial PMT Protection
In all atrial-controlled dual-chamber modes, Stratos CRT-Ps start the PMT protection interval after each ventricular stimulus. This prevents retrograde conduction and triggering of pacemaker-mediated tachycardias (PMTs). Right ventricular extrasystoles begin an extended PMT interval.
In all dual-chamber modes controlled by the ventricle, the Stratos CRT-Ps start the PMT protection interval after each initial (right or left) ventricular event.
The PMT protection interval after a Vp is freely programmable, while the PMT interval after VES is automatically set to 225 ms greater than the PMT interval after Vp (Nominal value: 250 ms/ AUTO (175…(5)…600 ms).
If an atrial event occurs within the atrial PMT protection interval, the atrial event is classified such that the AV delay is not restarted.
In the Stratos CRT-Ps, the PMT protection interval is started with a right or left ventricular paced event.