3 NASPE/BPEG Generic Pacemaker Code What isstimulated?I0=NoneA=Atrium V=Ventricle D=Dual (A+V)S=Single(A or V)What issensed?II0=NoneA=Atrium V=Ventricle D=Dual (A+V)S=Single(A or V)Reaction tosensingIII0=None T=Triggered I=Inhibited D=Dual (T+I)Rate ModulationIV0=None R=Rate ModulationMultisite PacingV0=NoneA=Atrium V=Ventricle D=Dual (A+V)The Revised NASPE/BPEG Generic Code forAntibradycardia, Adaptive-Rate, and MultisitePacing,PACE , Volume 25, No. 2, February 2002
4 Pacing systems AAI(R) VVI(R) DDD(R) VDD(R) = Sensing point = Stimulation point= Sensing and Stimulation point
5 A-AThis presentation is on atrial-based DDD timing. This is the timing system we have had since Affinity. Main timer is the A-A timer, generally corresponding to the basic rate. The timer starts with an atrial event whether paced or sensed. And if it times out, you will see an atrial stimulus on the ECG.
6 A-AAV DelayIn parallell to the A-A timer, AV delay runs. Starting with an paced atrial event. And if it times out, you will see an ventricular stimulus on the ECG.
7 A-APV DelayPV delay is like the AV delay but the starting point is the sensing of a P-wave.
8 AV and PV Delay...To make haemodynamics equivalent whether the atrium is paced or sensed, the AV and PV delays are separately programmable. Per definition an AV delay starts the atrial depolarisation and the PV delay detects an already ongoing depolarisation. Hence, to get the same haemodynamics, PV delay is usually programmed slightly shorter than the AV delay.170 ms150 ms
9 AV and PV interval... Late atrial activation In some cases, the atrial lead sits in a slow conducting part of the atrium, resulting in late atrial activation. To some extent, you can limit the haemodynamic consequences by programming AV and PV delays differently.250 ms150 msThe AV Delay can be programmed max. 100 ms longer than the PV Delay
10 Late Atrial Activation In this case: AV Delay should be 80 ms longer than PV Delay
11 A-AAV DelayBoth the AV and PV delay can be terminated by sensing of a ventricular event.
12 A-A terminated by intrinsic P-wave AV DelayThe A-A timer can be terminated by sensing of an atrial event, restarting a new A-A timer and a PV delay.A-A terminated by intrinsic P-wave
13 A-A – AV delay timer starts on detection of a PVC A-A terminated by a PVCA-A – AV delay timer startson detection of a PVCThe A-A timer can also be terminated by a ventricular event. Per definition this would now be a PVC. This ventricular event restarts a modified A to A timer. It is reduced by the AV delay to avoid an extra long pause until the next ventricular paced event.
14 Post Ventricular Atrial Refractory Period A-AAV DelayPVARPPost Ventricular Atrial Refractory PeriodProgrammable refractory period on the atrial channel is called PVARP. It starts with a ventricular event paced or sensed.
15 AV/PV Delay + PVARP = Total Atrial Refractory Period, TARP A-AAV DelayPVARPIn fact, the atrial channel is refractory also during the AV/PV delay. TARP is not directly programmable, but will play a significant role in upper rate behaviour.AV/PV Delay + PVARP = Total Atrial Refractory Period, TARP
16 Example of programmability... 25,30, 40, 50…170…350150200250300350400450500175225275325375425475
17 Noise Mode, Atrial Channel PVARPThe main refractory periods, in this case PVARP, consists of two parts, one absolute refractory and one relative refractory part. Noise mode appears when signals of a very high rate are picked up in the relative refractory period. The refractory period will be prolonged as long as these high rate signals keep coming in. The effect of this is basic rate pacing.A-A IntervalAbsoluteRelativeProgrammable PVARP
20 Ventricular Refractory Period A-AAV DelayPVARPVRPThe ventricular refractory period starts with a ventricular event, paced or sensed.Ventricular Refractory Period
21 Ventricular Blanking Period A-AAV DelayPVARPVRPVentricular blanking period appears on the ventricular channel after atrial stimulation only. Reason for this is to avoid cross talk, see next slide.Ventricular Blanking Period
22 Far-field sensing Crosstalk Intrinsic activity is sensed in the = Sensing point= Stimulation point= Sensing and Stimulation pointFar-field sensingIntrinsic activityis sensed in the“wrong” chamberCrosstalkPacemaker activity issensed in the “wrong” chamberNote that cross talk can only appear on the ventricular channel. The atrial channel would be in PVARP when the ventricular stimulation appears.
23 Example of programmability... 12…51ms125175225275325375425475150200250300350400450
24 Maximum Tracking Rate Interval A-AAV DelayPVARPVRPMaximum tracking rate interval corresponds to the programmed maximum tracking rate. It starts with a ventricular event, paced or sensed.MTRIMaximum Tracking Rate Interval
27 A-A AV Delay PVARP VRP MTRI MSRI Maximum sensor rate interval corresponds to the programmed maximum sensor rate. (Since this is an atrial based timing, it starts with the atrial event paced or sensed.)MTRIMSRI
30 DDD(R) Pacing States AV-Pacing AV pacing appears at basic rate or in a rate modulated system at sensor driven rate. In today’s devices, there are many more possibilities as well, for instance, AF suppression or rest rate.
31 DDD(R) Pacing States PV-Pacing P-wave tracking. This would be the typical pacing state of an AV block patient.
33 DDD(R) Pacing States AR-Pacing Atrial stimulation with intrinsic conduction. This would be the typical pacing state of an Sinus Node Disease patient.
34 Pacing States A V A R P V P R It might facilitate interpretation to make the annotations on a Xerox copy…
35 Markers P R A V P R Atrial Refractory period 142546694170617759Atrial Refractory periodPRVentricular Refractory period
36 DDI TimingDDI(R) is active during mode switch…2
37 NASPE/BPEG Generic Pacemaker Code What isstimulated?I0=NoneA=Atrium V=Ventricle D=Dual (A+V)S=Single(A or V)What issensed?II0=NoneA=Atrium V=Ventricle D=Dual (A+V)S=Single(A or V)Reaction tosensingIII0=None T=Triggered I=Inhibited D=Dual (T+I)Rate ModulationIV0=None R=Rate ModulationMultisite PacingV0=NoneA=Atrium V=Ventricle D=Dual (A+V)The Revised NASPE/BPEG Generic Code forAntibradycardia, Adaptive-Rate, and MultisitePacing,PACE , Volume 25, No. 2, February 2002
38 AVI AEI VEI PVARP VRP MSRI DDI could be programmed or appear as the mode during mode switch. DDI has ventricular based timing. At the ventricular event, both an atrial escape interval and a ventricular escape interval starts.VRPMSRI
39 AVI AEI VEI PVARP VRP MSRI If a high atrial rate is detected, the ventricular rate will not be affected.VRPMSRI
43 Rest Rate, and it’s Sensor Driven! Basic RateRest Rate is sensor driven – patients can rest when they feel like it.It is technically based on statistics long term (Activity Variance Histogram) compared to short time.Rest Rate
44 Rate Hysteresis Classic single-chamber version Basic Rate Hysteresis RateClassical single-chamber rate hysteresis. Today almost exclusively used in VVI(R) in conjunction with Autocapture. This is to avoid a series of (pseudo)fusion beats.
45 Advanced Hysteresis Response Intervention DurationSensorRecoveryRateSearch IntervalIntervention- rateBasic rateHysteresis rateAdvanced hysteresis response is mainly used together with DDI mode in patients with vasovagal syncope.Cycle CountCycle Count
46 Crosstalk…A VP VARCrosstalk events marked by the arrows.
47 Decrease atrial output? Decrease ventricular sensitivity? CrosstalkDecrease atrial output?Decrease ventricular sensitivity?Prolong ventricular blanking?Enable Ventricular Safety Standby!The classical recommendations to avoid crosstalk. They are not easy to follow, except for the use of Ventricular Safety Standby.
49 Ventricular Safety Standby Crosstalk V. Safety Pacing after 120 ms
50 Is Ventricular Safety Pacing Present In This Panel? Yes, in the last event! But it is due to a late cycle PVC (no crosstalk).
51 Vetricular Safety Pacing Other tracing – same story.
52 Ventricular Safety Standby Sensing in Crosstalk Detection WindowV. Safety Pacing after 120 ms
53 Ventricular Safety Standby Blanking Period Undersensing V. Pacing after programmed AV IntervalWe can enjoy the shortest Ventr. Blanking in the industry. This is important – look at the next slide!
54 Blanking period undersensing can be dangerous at long AV intervals Blanking period under-sensing can be dangerous if AV delay is programmed long. Note that this will happen with AutoCapture as well when the backup pulse will come approximately 100 milliseconds after the initial stimulus. AICS can also produce a dangerous situation. This can be the case in competitors devices as well, of course. Again, we have the shortest ventr. Blanking!Conclusion, it is preferable to have a very short blanking period if possible.Blanking period undersensing can be dangerous at long AV intervals
55 AutoIntrinsic Conduction Search Neg. AV/PV Hysteresis AF Suppression Special FeaturesAutoIntrinsic Conduction SearchNeg. AV/PV HysteresisAF Suppression
57 AutoIntrinsic Conduction Search in Intermittent High Degree AV-Block PV150788938Programme the optimal AV/PV Delay for time in high degree AV-block1Add an AutoIntrinsic Conduction Search of e.g ms to allow for intrinsic conduction within a hemodynamically acceptableconduction time2Philosophy: High degree AV block will need relatively high percentage ventricular stimulation. Hemodynamically optimized AV delay is important.150Progr.PV Interval100AICS
58 AutoIntrinsic Conduction Search in Intermittent High Degree AV-Block P232RThe pacemaker will now allowfor intrinsic conduction withinthe prolonged AV/PV Delay,in this case 250 ms.634812150Progr.PV Interval100AICS
59 AutoIntrinsic Conduction Search in Intermittent High Degree AV-Block msmsms150 ms150 msProgrammed AV/PV DelayAutoIntrinsic Conduction Search
60 AutoIntrinsic Conduction Search in Intermittent High Degree AV-Block 150 msSearchmsmsms150 msProgrammed AV/PV DelayAutoIntrinsic Conduction Search
61 AutoIntrinsic Conduction Search in Sinus Node Disease PR171767938Let the pacemaker measure the PR- and AR-Interval at rest1Program PV- and AV Delayslightly longer thanintrinsic conduction2Add an AutoIntrinsic Conduction Search of 120 ms3Philosophy: SND will need low percentage, if any, ventricular stimulation. Avoiding un-necessary ventricular stimulation is in focus.200ProgrammedPV Interval120AICS
62 AutoIntrinsic Conduction Search in Sinus Node Disease P268RThe pacemaker will now allowfor intrinsic conduction withinthe prolonged AV/PV Delay,in this case 320 ms.670841200ProgrammedPV Interval120AICS
63 AutoIntrinsic Conduction Search in Sinus Node Disease Preference of intrinsic conduction...msmsmsmsmsProgrammed AV/PV DelayAutoIntrinsic Conduction Search
64 AutoIntrinsic Conduction Search in Sinus Node Disease Back-up pacing if, against all odds, intrinsic conduction is lost...ms200 ms200 ms200 ms200 msProgrammed AV/PV DelayAutoIntrinsic Conduction Search
67 Negative AV/PV-hysteresis Measure, with the puls generator, the PR intervalProgram, with the aid of Echo, the optimal PV- Delay. (Longest PV Delay with full capture)To make this dynamic, program how much faster pacing should be, compared to a sensed R-wave (PRMeas – PVOpt). This is called Neg. AV/PV Delta.
70 AF 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
71 AF Suppression, AFx MSR AFx Intrinsic Rate Basic Rate Searches will happen approximately 2-3 times a minute.Basic Rate
72 AF Suppression, AFxAFxOverdrive: 10 min-1 at rate 60 min-1 and 5 min-1 at rate 150 min-1.
73 AF Suppression, AFx Search for intrinsic activity 67 66 65 Activity found (two P-waves)6465Increase stimulation rate74To apply overdrive, two P-waves has to be sensed, the second within 16 cycles from the first.
74 AF Suppression, AFx!… and to programme:ON / OFF