66 Stratos LV/LV-T Technical Manual

In the DDI/T and DVT pacing modes, the basic interval is not restarted if ventricular sensing occurs within the AV delay.

CAUTION

Programmed to Triggered Modes – When programmed to triggered modes, pacing rates up to the programmed upper limit may occur in the presence of either muscle or external interference.

Triggered Modes – While the triggered modes (DDT, DVT, DDTR/A, DDTR/V, DDI/T, VDT, VVT, and AAT) can be programmed permanently, these modes are intended for use as temporary programming for diagnostic purposes. In triggered pacing modes, pacing pulses are emitted in response to sensed signals, and therefore the pacing pulse can be used as an indicator, or marker of sensed events for evaluating the sensing function of the pulse generator using surface ECG. However, real-time telemetry of marker channels and/or intracardiac electrogram via the programmer and programming wand is recommended over the use of a triggered pacing mode in the clinical setting. A triggered pacing mode may be preferred in situations where positioning the programming head over the pulse generator would be impossible or impractical (i.e., during exercise testing or extended Holter monitoring).

Another possible application of triggered modes is to ensure pacing as a short term solution during a period of inhibition of pacing by extracardiac interference, mechanical noise signals, or other sensing abnormalities. Because triggered modes emit pacing pulses in response to sensed events, this may result in unnecessary pacing during the absolute refractory period of the myocardium, inappropriate pacing in response to oversensing of cardiac or extracardiac signals. The risks associated with triggered pacing include excessive pacing, arrhythmias due to the R-on-T phenomenon, and early battery depletion. Therefore, it is important that the triggered modes are not used for long term therapy, and that the CRT-P is always returned to a non-triggered permanent program.