2. Appendix E Pacemakers
Gail Walraven, Basic Arrhythmias, Seventh Edition ©2011 by Pearson Education, Inc., Upper Saddle River, NJ

3. Artificial Pacemaker
A device used to provide artificial electrical stimulus to myocardial tissue to induce myocardial depolarization
Gail Walraven, Basic Arrhythmias, Seventh Edition ©2011 by Pearson Education, Inc., Upper Saddle River, NJ

4. Purpose of a Pacemaker
The primary purpose is to maintain an adequate rate if the inherent pacemaker is too slow, or if conduction is blocked.
Gail Walraven, Basic Arrhythmias, Seventh Edition ©2011 by Pearson Education, Inc., Upper Saddle River, NJ

5. Pacemaker Spikes
Each time a pacemaker fires, it produces a spike on the EKG.
To evaluate effectiveness, look at the relationship between the pacemaker spikes and the patient’s own complexes.
Gail Walraven, Basic Arrhythmias, Seventh Edition ©2011 by Pearson Education, Inc., Upper Saddle River, NJ

6. Pacemaker Components
Power Source: battery unit called a pulse generator
Conducting Wire: electrode that goes to the heart to provide the stimulus
Return Wire: wire that returns to battery unit to complete the electrical circuit
Gail Walraven, Basic Arrhythmias, Seventh Edition ©2011 by Pearson Education, Inc., Upper Saddle River, NJ

7. Types of Pacemakers Temporary Permanent transvenous transcutaneous
implanted
Gail Walraven, Basic Arrhythmias, Seventh Edition ©2011 by Pearson Education, Inc., Upper Saddle River, NJ

8. Pacemaker Placement
Gail Walraven, Basic Arrhythmias, Seventh Edition ©2011 by Pearson Education, Inc., Upper Saddle River, NJ

9. Depolarization of the heart in response to an artificial stimulus.
Capture
Depolarization of the heart in response to an artificial stimulus.
Gail Walraven, Basic Arrhythmias, Seventh Edition ©2011 by Pearson Education, Inc., Upper Saddle River, NJ

10. Chambers Paced Atrial Pacemakers: stimulate only atria
Ventricular Pacemakers: stimulate only ventricles
AV synchronous pacemakers: stimulate both atria and ventricles
Single-chamber pacemakers: stimulate either atria or ventricles, but not both
Dual-chamber pacemakers: stimulate both atria and ventricles
Gail Walraven, Basic Arrhythmias, Seventh Edition ©2011 by Pearson Education, Inc., Upper Saddle River, NJ

11. Smart Pacemaker
Technology enables these devices to sense intrinsic electrical activity and respond appropriately by pacing or withholding stimulation in synchrony with patient’s rhythm.
Gail Walraven, Basic Arrhythmias, Seventh Edition ©2011 by Pearson Education, Inc., Upper Saddle River, NJ

12. It is possible for a pacemaker to be both.
Pacing Response
Triggered: fixed-rate, fires regardless of underlying activity
Inhibited: demand pacemaker, fires only when needed
It is possible for a pacemaker to be both.
Gail Walraven, Basic Arrhythmias, Seventh Edition ©2011 by Pearson Education, Inc., Upper Saddle River, NJ

13. Pacemaker Classification
Chamber Paced
Chamber Sensed
Response
Gail Walraven, Basic Arrhythmias, Seventh Edition ©2011 by Pearson Education, Inc., Upper Saddle River, NJ

14. Pacemaker Classification
Gail Walraven, Basic Arrhythmias, Seventh Edition ©2011 by Pearson Education, Inc., Upper Saddle River, NJ

15. Common Single-Chamber Pacemakers
Ventricular Demand (VVI)
Atrial Demand (AAI)
Gail Walraven, Basic Arrhythmias, Seventh Edition ©2011 by Pearson Education, Inc., Upper Saddle River, NJ

16. Common Single-Chamber Pacemakers
AV Synchronous (VDD)
AV Sequential (DVI)
Optimal (DDD)
Gail Walraven, Basic Arrhythmias, Seventh Edition ©2011 by Pearson Education, Inc., Upper Saddle River, NJ

17. Assessment of Pacemaker Function on the EKG
Identify pacemaker spikes.
Look at relationship between spikes and patient’s complexes.
Is pacemaker doing what it is supposed to do?
Is rate reasonable?
Are spikes competing or falling near T waves?
Is pacemaker functioning consistently and reliably?
Gail Walraven, Basic Arrhythmias, Seventh Edition ©2011 by Pearson Education, Inc., Upper Saddle River, NJ

18. Pacemaker Malfunction Failure to Capture
Pacemaker fires, but no capture occurs.
EKG has spike not followed by complex.
Gail Walraven, Basic Arrhythmias, Seventh Edition ©2011 by Pearson Education, Inc., Upper Saddle River, NJ

19. Pacemaker Malfunction Competition
Artificial pacemaker fires without regard to underlying rhythm.
Both pacemakers compete for control of the heart.
Gail Walraven, Basic Arrhythmias, Seventh Edition ©2011 by Pearson Education, Inc., Upper Saddle River, NJ

20. Pacemaker Malfunction Runaway Pacemaker
Pacemaker fires too rapidly but still captures.
Caused by malfunctioning impulse generator.
Gail Walraven, Basic Arrhythmias, Seventh Edition ©2011 by Pearson Education, Inc., Upper Saddle River, NJ

21. Pacemaker Malfunction Battery Failure
Battery has insufficient power to initiate pacemaking stimulus.
EKG shows absence of spikes in a rhythm normally paced.
Gail Walraven, Basic Arrhythmias, Seventh Edition ©2011 by Pearson Education, Inc., Upper Saddle River, NJ

22. Treatment of Malfunctioning Pacemaker
Pacemakers are a treatment, so they aren’t treated when they malfunction.
When a pacemaker malfunctions, treatment is directed at the patient and the underlying rhythm.
Replacement of the malfunctioning pacemaker might be an option.
Gail Walraven, Basic Arrhythmias, Seventh Edition ©2011 by Pearson Education, Inc., Upper Saddle River, NJ

23. Paced Complexes
Pacemakers often supplement, rather than supplant, the patient’s own rhythm. This rhythm strip shows a ventricular demand pacemaker that fires occasionally to supplement the patient’s underlying atrial fibrillation. Complexes C, D, E, and G are the patient’s normally conducted beats (note narrow QRS complexes). Complexes A, B, and F are initiated by the artificial ventricular pacemaker (note spikes preceding each wide QRS).
Gail Walraven, Basic Arrhythmias, Seventh Edition ©2011 by Pearson Education, Inc., Upper Saddle River, NJ

24. Pacemaker Rhythms (Ventricular)
A properly functioning pacemaker will show a sharp spike, followed immediately by depolarization of the chamber it is intended to pace. This rhythm strip shows ventricular pacemaker capturing every beat. Note absence of mappable P waves and sharp spikes followed immediately by wide QRS complexes.
Gail Walraven, Basic Arrhythmias, Seventh Edition ©2011 by Pearson Education, Inc., Upper Saddle River, NJ

25. Pacemaker Rhythms (AV Synchronous)
This rhythm strip shows an AV synchronous pacemaker capturing every beat. Note pacemaker spikes preceding both atrial and ventricular depolarization.
Gail Walraven, Basic Arrhythmias, Seventh Edition ©2011 by Pearson Education, Inc., Upper Saddle River, NJ

26. Properly Functioning Ventricular Demand Pacemaker
The pacemaker is set to fire whenever the patient’s intrinsic rate falls below 60 bpm. The first three complexes show the patient’s heart depolarizing at about 68 bpm, so the pacemaker inhibited itself. It kicked in at the fourth complex when the rate dropped, and continued to pace at a rate of 60 bpm.
Gail Walraven, Basic Arrhythmias, Seventh Edition ©2011 by Pearson Education, Inc., Upper Saddle River, NJ

27. Failure to Capture
The underlying rhythm is atrial fibrillation, and the ventricular pacemaker is set at an unusually slow rate of 44 bpm. It fails to sense the patient’s own complexes and continues to fire regularly, regardless of underlying ventricular activity. When the pacemaker stimulus finds the ventricles refractory, it fails to capture.
Gail Walraven, Basic Arrhythmias, Seventh Edition ©2011 by Pearson Education, Inc., Upper Saddle River, NJ

28. Competition
This strip shows pacemaker spikes at a rate of 100 bpm, with an underlying ventricular tachycardia/fibrillation. The pacemaker is competing for control of the heart, but the irritable ventricular foci are winning.
Gail Walraven, Basic Arrhythmias, Seventh Edition ©2011 by Pearson Education, Inc., Upper Saddle River, NJ

29. Sample Pacemaker Strips
Gail Walraven, Basic Arrhythmias, Seventh Edition ©2011 by Pearson Education, Inc., Upper Saddle River, NJ

30. Fully Functional Atrial Pacemaker Showing 100% Capture
Gail Walraven, Basic Arrhythmias, Seventh Edition ©2011 by Pearson Education, Inc., Upper Saddle River, NJ

31. Ventricular Pacemaker Showing 100% Capture (with Underlying Complete Heart Block)
Gail Walraven, Basic Arrhythmias, Seventh Edition ©2011 by Pearson Education, Inc., Upper Saddle River, NJ

32. AV Sequential (DVI) Pacemaker
Gail Walraven, Basic Arrhythmias, Seventh Edition ©2011 by Pearson Education, Inc., Upper Saddle River, NJ

33. Properly Functioning Demand Pacemaker
Gail Walraven, Basic Arrhythmias, Seventh Edition ©2011 by Pearson Education, Inc., Upper Saddle River, NJ

34. DDD Pacemaker in AV Sequential Mode
Gail Walraven, Basic Arrhythmias, Seventh Edition ©2011 by Pearson Education, Inc., Upper Saddle River, NJ

35. Sinus Rate Accelerates and Regains Control from Ventricular Demand Pacemaker
Gail Walraven, Basic Arrhythmias, Seventh Edition ©2011 by Pearson Education, Inc., Upper Saddle River, NJ

36. Pacemaker Fails to Depolarize Consistently, Indicating Lead Fracture or Displacement
Gail Walraven, Basic Arrhythmias, Seventh Edition ©2011 by Pearson Education, Inc., Upper Saddle River, NJ

37. Ventricular Pacemaker with 100% Capture
Gail Walraven, Basic Arrhythmias, Seventh Edition ©2011 by Pearson Education, Inc., Upper Saddle River, NJ

38. Atrial Pacemaker with 100% Capture
Gail Walraven, Basic Arrhythmias, Seventh Edition ©2011 by Pearson Education, Inc., Upper Saddle River, NJ

39. Non-capturing Pacemaker Competing with Supraventricular Rhythm in First Part of Strip, Converting to Ventricular Tachycardia Competing with Pacemaker at End of Strip
Gail Walraven, Basic Arrhythmias, Seventh Edition ©2011 by Pearson Education, Inc., Upper Saddle River, NJ

40. Ventricular Demand Pacemaker
Gail Walraven, Basic Arrhythmias, Seventh Edition ©2011 by Pearson Education, Inc., Upper Saddle River, NJ

41. Ventricular Pacemaker Showing 100% Capture
Gail Walraven, Basic Arrhythmias, Seventh Edition ©2011 by Pearson Education, Inc., Upper Saddle River, NJ