2AF Suppression™ Algorithm Overview St. Jude Medical recently completed the ADOPT-A which yielded favorable results in support of the proprietary AF Suppression algorithm.(Refer to bullets)
3AF Suppression™ Algorithm Overview The goal is to keep atrial arrhythmias from occurringPrevention of atrial fibrillationA fib begets A fib!Solution: An algorithm designed to keep the atrial pacing rate just above the patient’s changing intrinsic atrial rate, resulting in constant atrial pacing
4AF Suppression, AFx> 90% Atrial PacingAFx ensures a high percentage of atrial stimulation at a rate following the patients natural circadian variations, thereby maintaining control of the atrium, reducing ectopy, and suppressing atrial tachyarrhythmias
5AF Suppression, AFx MSR AFx Intrinsic Rate Basic Rate Searches will happen approximately 2-3 times a minute.Basic Rate
6AF Suppression, AFxAFxOverdrive: 10 min-1 at rate 60 min-1 and 5 min-1 at rate 150 min-1.
7AF Suppression, AFx Search for intrinsic activity 67 66 65 Activity found (two P-waves)6465Increase stimulation rate74APAPAPASASAPAPAPVPTo apply overdrive, two P-waves has to be sensed, the second within 16 cycles from the first.VPVPVPVPVPVPVPVP
12AF Suppression™ Algorithm Overview When the algorithm is activated, the device looks for2 P-waves within 16 cyclesOnly P-waves in the alert period will be usedIf 2 P-waves within 16 cycles are seen, the device will increase the atrial pacing rate
13AF Suppression™ Algorithm Overview Only 1 P-wave was seen. Therefore, NO Overdrive occursStart 16-cycle counterEnd 16-cycle counterAS AP AP AP AP AP AP AP AP AP AP AP AP AP AP AP APAS = P-waveAP = Atrial pacingNote: Notice how the algorithm starts with a “0” not a “1”
14AF Suppression™ Algorithm Overview 2 P-waves were seen therefore, Overdrive occursStart 16-cycle counterStart OverdriveAS AP AP AP AP AP AP AP AP AP AP AP AP AP AP ASAS = P-waveAP = Atrial pacing
15AF Suppression™ Algorithm Overview 2 P-waves were seen therefore, Overdrive occursOverdrive RatePacing RateASAS
16AF Suppression™ Algorithm Overview A look-up table within the device determines the Overdrive rateThe current atrial pacing rate is used to determine the increase in atrial rateThe Maximum AF Suppression rate is the maximum rate for atrial overdrive pacing when AF Suppression is programmed on
17AF Suppression™ Algorithm Overview Once the atrial Overdrive rate is determined, the device will pace at this rate for a programmable number of cycles15 (nominal), 20, 25, 30, 35 or 40 cyclesWhen AF suppression is programmed ON, the Overdrive Pacing Cycles is the only programmable parameterCycle count of 15 was programmed most often during the Adopt-A clinical trial
18AF Suppression™ Algorithm Overview Once the number of Overdrive cycles has been completed the Rate Recovery phase will startIf the Overdrive rate is 100 ppm - 12 ms will be added to each cycle, resulting in a lower rateIf the Overdrive rate is >100 ppm - 8 ms will be added to each cycle, resulting in a lower rate
19AF Suppression™ Algorithm Overview 2 P-waves were seen therefore, Overdrive occurs followed by Rate RecoveryOverdrive RateRate RecoveryPacing RatePacing RateASAS
20AF Suppression™ Algorithm Overview What if there are additional P-waves sensed during the Overdrive portion?
21AF Suppression™ Algorithm Overview If 1 P-wave is sensed during the Overdrive portion, the 16 cycle counter will startIf 2 P-waves are sensed within 16 cycles, the device will increase the atrial rate and Overdrive will start
23AF Suppression™ Algorithm Overview What if 1 P-wave is sensed in the Rate Recovery portion?
24AF Suppression™ Algorithm Overview If 1 P-wave is sensed during the Rate Recovery portion, the 16 cycle counter will startIf 2 P-waves are sensed within 16 cycles, the device will increase the atrial rate and Overdrive will start