Mintek LV, LV-T AV Hysteresis, 2.3.9.2AV Hysteresis, 2.3.9.3AV Repetitive Hysteresis

Stratos LV/LV-T Technical Manual 79

The Dynamic AV Delay is intended to mimic the physiologic, catecholamine-induced shortening of the AV Delay with

increasing rate. It also serves for automatic prevention/termination of “circus movement” pacemaker mediated tachycardia and for prevention of reentrant supraventricular tachycardia (see PMT Management section).

2.3.9.2AV Hysteresis

AV Hysteresis allows a user-programmable change in AV delay that is designed to encourage normal conduction of intrinsic signals from the atrium into the ventricles. An AV hysteresis interval can be programmed OFF or a value range of 10…(10)…1000. With AV hysteresis enabled, the AV delay is extended by a defined time value after sensing a ventricular event. The long AV interval is used as long as intrinsic ventricular activity is detected. The programmed short AV delay interval resumes after a ventricular paced event.

CAUTION

AV Hysteresis – If the AV hysteresis is enabled along with the algorithm for recognizing and terminating PMTs (PMT management), the AV delay for recognizing and terminating a PMT has a higher priority than the AV hysteresis.

2.3.9.3AV Repetitive Hysteresis

With AV Repetitive Hysteresis, the AV delay is extended by a defined hysteresis value after sensing an intrinsic ventricular event. When a ventricular stimulated event occurs, a long AV delay is used for the programmed number of cycles. (OFF; 1…(1)…10 cycles). If an intrinsic rhythm occurs during one of the repetitive cycles, the long duration AV delay interval remains in effect. If an intrinsic rhythm does not occur during the repetitive cycles, the original AV delay interval resumes.