Estella Pulse Generators - BIOTRONIK USA - News

58 Estella Pulse Generators Technical Manualduring one of the repetitive cycles, the long duration AV delay intervalremains in effect. If an intrinsic rhythm does not occur during therepetitive cycles, the original AV delay interval resumes.7.5.3.4 AV Scan HysteresisWith AV Scan Hysteresis enabled, after 180 consecutive pacing cycles,the AV delay is extended for the programmed number of pacing cycles. (1… 10). If an intrinsic rhythm is detected within the extended AV delay, thelonger AV delay remains in effect. If an intrinsic rhythm is not detectedwithin the number of scan cycles, the original AV delay value resumes.7.5.3.5 Negative AV Delay HysteresisWith Negative AV Delay Hysteresis, the AV delay is decreased by adefined value after a ventricular event is sensed, thereby promotingventricular pacing. The Negative AV Delay Hysteresis value correspondsto the programmed AV delay, multiplied by approximately 2/3, limited toa minimum of 15 ms.The normal AV delay resumes after the programmed number ofconsecutive ventricular paced events (Repetitive Negative AV DelayHysteresis) elapses.CautionNegative AV Delay Hysteresis—This feature insures ventricularpacing, a technique which has been used in patients withhypertrophic obstructive cardiomyopathy (HOCM) with normalAV conduction in order to replace intrinsic ventricular activation.No clinical study was conducted to evaluate this feature, andthere is conflicting evidence regarding the potential benefit ofventricular pacing therapy for HOCM patients. In addition, thereis evidence with other patient groups to suggest that inhibitingthe intrinsic ventricular activation sequence by right ventricularpacing may impair hemodynamic function and/or survival.7.5.3.6 I-OptThe I-Opt function serves to support the intrinsic rhythm of the heart. Itactivates all of the AV hysteresis function parameters in a single step.