1) WARAD (Window of Atrial Rate Acceleration Detection)- purely atrial based adapative TARP algorithm based on calculation of TARP from a percentage of the previous normal A-A interval(s). Except for post-PVC function, there is no PVARP in Sorin devices. PVARP is non-physiologic; there is no natural refractory period in the heart that corresponds to it; it is the reason why many programming limitations in devices that depend on it. With WARAD, the TARP is determined by the patients own natural changes in rate; not arbitrary programmed values. It distinguishes "normal" events from "pathological" events. [ICDs and PMs]
2) FMS (Fallback Mode Switching)- mode switching based on statistical analysis. First, PAC sensed in WARAD puts FMS into suspicion phase. During suspicion phase, ventricle cannot track faster than 120 bpm. FMS looks for a "strong" or "weak" criterion based on number of V cycles with A events falling into WARAD. If criterion is met, then mode switch to DDI occurs. This analysis allows for atrial undersensing to occur during mode switch. Traditional "rate vs run" algorithms can result in V tracking to the max rate and are dependant on 100% atrial sensing. [ICDs and PMs]
3) V AutoThreshold- Automatically runs its own calibration test each it performs automatic threshold test (unlike STJ's AutoCapture which can only be calibrated or re-calibrated with the programmer). In case of an indeterminate test, will re-test immediately or will temporarily program to higher output and repeat test at next indicate time (unlike MDT's CaputreManagement which will program to high output and stay there until reprogrammed with the programmer). [PMs]
4) Dual Sensor Rate Response- One of only two manufacturers to offer dual sensor rate response (MV & accelerometer). Only one to offer the option of MV only programming (BSC only offers MV+Accel or Accel only). [PMs]
5) Rest Rate- Rest rate algorithm is based 3 physiologic criteria (not programmed clock settings). If cardiac rest, respiratory rest and lack of frequent ectopics is met, then rate can drop to programmed rest rate. If frequent ectopics occur during rest rate, rate will rapidly rise back to lower rate potentially overdriving the ectopics, lessening the chance of arrhythmias during slower rates. [PMs]
6) AIDA+ (Automatic Interpretation for Data Analysis)- diagnostic package using Holter technology to record up to 6 months of A & V marker channels. Is downloaded to programmer and analyzed. Only diagnostics available that gives textual feedback of automatically analyzed data. Graphical evidence to back-up textual feedback is presented. Will give what current related settings are and will make suggested changes. [PMs and ICDs]
7) ASC (Automatic Sensitivity Control)- uses a stepdown method and automatically adjusts the functional sensing floor depending on the size of the sensed V. In the presence of large V signals, the sensing floor is less sensitive allowing for avoidance of sensing noise and other small extraneous signals. On small V signals, the sensing floor is more sensitive to allow for detection of VF. ASC also has a programmable post-Vpacing margin to allow the step over the Twave to be temporarily less sensitive to avoid Twave oversensing without changing the entire ASC algorithm. In addition, there is also a post-Vsensing/pacing margin to allow the atrial channel to be temporarily less sensitive following the V to avoid far-field Rwave sensing. Hence, this algorithm addresses two of the three main causes for inappropriate shocks- noise and inappropriate sensing of Rwaves or Twaves. [ICDs]
8) PARAD+ (P And R Arrhythmia Discrimination)- When Sorin designed it's dual chamber ICD, it did so from the ground up. They did so with the PARAD algorithm as well. Other companies already had single chamber ICDs and modified them to include atrial hardware and started with the same discriminators as were in the single chamber ICDs- stability and onset. The PARAD algorithm was designed from the start using criteria that an EP typically uses to discriminate arrhythmias in the lab. In addition to stability and onset, the algorithm uses association of A to V, level of A & V association, and chamber of origin. To better discriminate rapidly conducted AF which starts to look regular and commonly fools most discrimination algorithms, another criteria called VT Long Cycle was added (this criteria is also available in the single chamber devices). Since MDT and STJ seem to have recently made it envouge to refer to computer models, Hintringer et al is the only head-to-head comparison of algorithms from all 5 manuafacturers and showed the PARAD+ algorithm to be most effective at discriminating SVTs from VTs. It should also be noted that Sorin devices detect and discriminate throughout charging. Also, when programmed to VVI, Sorin dual chamber devices can continue to monitor the atrial channel and provide dual chamber discrimination. Sorin devices never uses committed shocks. [ICDs]
9) BTO (Brady-Tachy Overlap)- Sorin devices are the only devices on the market to allow pacing and tracking into the Slow VT zone. Every other company must maintain some margin between its max rate and its slowest tachy detection interval. This means that a physician need not compromise the ability of their patients to exercise when they have slow VTs. This is especially true for patients with heart failure in whom slow VTs are more prevalent as well as patients with doucmented VTs that are on antiarrhythmics. [ICDs]