Dual Chamber Temporary Pacing Operations & Troubleshooting

1. Dual Chamber Temporary PacingOperations & Troubleshooting

2. Indications for Dual Chamber Temporary Pacing • Complete heart block • Sinus bradycardia • Bradycardia with congestive heart failure • Atrial and/or ventricular ectopic arrhythmia • Reentrant tachycardias • During pulse generator replacement

3. Indications for Dual Chamber Temporary Pacing • Prior to the implant of a permanent pacemaker • Temporary support of a patient after heart surgery • Acute myocardial infarction complicated by heart block • High rate burst stimuli for the treatment of some tachyarrhythmias

4. The NASPE/BPEG Generic (NBG) Code Position I II III IV V Category Chamber(s)Paced Chamber(s)Sensed Response toSensing ProgrammabilityRate Modulation AntitachyarrhythmiaFunction(s) O = None A = Atrium V = Ventricle D = Dual (A+V) O = None A = Atrium V = Ventricle D = Dual (A+V) O = None T = Triggered I = Inhibited D = Dual (T+I) O = None P = Simple Programmable M = Multiprogrammable C = Communicating R = Rate Modulation O = None P = Pacing S = Shock D = Dual (P+S) Manufacturer’sDesignationOnly S = Single (A or V) S = Single (A or V) Note: Positions I through III are used exclusively for antibradyarrhythmia function

5. Asynchronous Modes AOO VOO DOO

6. Ap Ap Ap Ap Ap * * * * * * * * * * ° Vp Vp Vs Vp Vp Vp DVI 1 2 3 4 5 6 = AV interval (140 ms) Lower rate = 60 ppm V-A interval = 860 ms = PVARP (250 ms) = indicates cycle restarted by sensed or paced event

7. DDD Pacing Chamber Paced Chamber Sensed Action or Responseto a Sensed Event D D D

8. DDD Pacemaker Provides: • AV Synchrony • Rate Variability Results in: • Changes in cardiac output • Management of rhythm • Improved quality of life

9. Parameter Adjustments of theTemporary DDD Pacemaker • Lower Rate • A–V Interval • Upper Rate • Output • Sensitivity • Refractory Period(PVARP)

10. ECG Function DDD Mode

11. Timing Intervals in milliseconds (ms) V–A 750 ms A–V 250 ms V–V 1000 ms DDD / 60 / 250 / 125 / 155

12. Calculation of Atrial Escape Interval Atrial Escape Lower Rate – A–V Interval = Interval V–V – A–V = V–A (ms) (ms) (ms) (60 ppm) 1000 – 250 = 750 (60 ppm) 1000 – 150 = 850 (70 ppm) 850 – 200 = 650

13. Proper Atrial Sensingis the “Heart” ofPhysiologic Pacing

14. A Pace / V Pace A–V Sequential Pacing V–A 750 ms A–V 250 ms V–V 1000 ms DDD / 60 / 250 / 150

15. A Pace / V Sense Atrial Pacing with Normal A–V Conduction Programmed Lower Rate1000 msActual V–V960 ms DDD / 60 / 200 / 150

16. A Sense / V Pace Atrial Synchronous Pacing Spontaneous Atrial Rate = 55 ppm Spontaneous Atrial Rate = 110 ppm DDD / 50 / 150 / 150

17. A Sense / V Sense Spontaneous P-Wave with Normal A–V Conduction Spontaneous Atrial Rate = 65 ppm Spontaneous P-R Interval = 160 ms DDD / 60 / 200 / 150

18. Timing Operations of DDD Pacing VentricularRate UpperRate AtrialTracking LowerRate Atrial Rate

19. Definitions PVARP – Post Ventricular Atrial Refractory Period Time after Vs or Vp when atrial rates are ignored A–V – Time from As or Ap to Vp in ms TARP – Total Atrial Refractory Period in ms

20. Refractory Period • Increase to prevent: • T-wave sensing • P-wave sensing • Decrease to permit tachy pacing

21. Wenckebach Operation

22. Wenckebach Operation AV AV W AV W AV W AV PVARP PVARP PVARP PVARP PVARP Upper Rate Upper Rate Upper Rate Upper Rate Upper Rate As As As As As As Vp Vp Vp Vp Vp W = Wenckebach Interval

23. 2 : 1 Block

24. 2 : 1 Block AV AV AV AV PVARP PVARP PVARP PVARP Upper Rate Upper Rate Upper Rate Upper Rate As As As As As As As As Vp Vp Vp Vp

25. Physiology of Retrograde Conduction 1. Loss of A-V synchrony due to a PVC 2. Sensed retrograde activation 3. A-V interval initiated PVC 4. Prolongation of A-V interval 5. Ventricular pacing synchrononized to retrograde P-waves

26. Pacemaker Mediated Tachycardia (PMT) • Fast ventricular paced rhythm • Synchronized to retrograde-conducted P-waves • Not normal sinus tachycardia

27. Thresholds

28. Feature of the Temporary DDD Pacemaker Atrial Output Control Ventricular Pulse Amplitude(ma) Pulse Width(ms)

29. Feature of the Temporary DDD Pacemaker Sensitivity 2.5 1.25 0.5

30. Troubleshooting

31. Undersensing Failure of the pacemaker to senseintrinsic R-waves or intrinsic P-waves

32. Undersensing • Battery depletion • Decreased QRS voltage • Fusion beat • Dislodged/fractured lead • Inappropriate sensitivity setting

33. Oversensing Inhibition of the pacemaker by events the pacemaker should ignore, e.g. EMI, T-waves, and myopotential

34. Oversensing • Myopotential inhibition • EMI • T-waves outside of refractory period • Dislodged/fractured lead • Inappropriate sensitivity setting

35. No Output Pacemaker fails to emit stimuliat the programmed intervals

36. No Output 1 2 3 4 5 • Battery depletion/pacemaker off • Oversensing AP AS AP AP AP VP VP VP VP VP No atrial output (on ECG) • Faulty cable connection • Dislodged/fractured lead

37. Loss of Capture Electrical stimuli delivered bythe pacemaker does not initiate depolarization of the atria or ventricle

38. Loss of Capture • Inappropriate output setting • Increased resistance to conduction • QRS complex not visible Atrial Noncapture Ventricular Noncapture Fusion • Dislodged/fractured lead • Tissue is refractory • Faulty cable connection

39. Ventricular Safety Pacing Ap Vp Ap = Atrial Pace Vp = Ventricular Pace ProgrammedA-V Interval Ventricular Blankingat Atrial Rate 12 ms Ventricular SafetyPace Interval 110 ms Programmed A-V Interval Ventricular Sensing within this period triggers a ventricular output at an A-V interval of 110 ms instead of programmed A-V interval. Ventricular Sensing during the remainder of the programmed A-V interval inhibits the ventricular output. If there is no sensed event, a ventricular output occurs at the programmed A-V interval.

40. Ap Ap Ap Ap Ap * * * * * * * * * * ° ° ° Vs Vp Vp Vs Vp Vs Vp Vp Ventricular Safety Pacing (VSP) 1 2 3 4 5 = AV interval (160 ms) Lower rate = 54 ppm Upper rate = 180 ppm V-A interval = 860 ms = PVARP (250 ms) = indicates cycle restarted by sensed or paced event