The document provides information about interpreting electrocardiograms (ECGs) from patients with pacemakers. It discusses various pacemaker modes, assessing capture and sensing functions, underlying cardiac rhythms, and what follow up actions may be needed based on the ECG patterns. Examples are presented to illustrate dual chamber pacing, assessing atrial and ventricular sensing, pacemaker-mediated tachycardia, undersensing, failure of capture, and magnet mode behavior.

1. Presented By:
Yasmeen Kamal
Tanta Rhythm Group (TRG)

3. A gentleman who had a pacemaker
implanted 3 years ago came to
your clinic to check on his device.
Unfortunately he forgot his card
So…. HOW will you deal with him ?

4. A 12 Lead ECG is made , what can you see ?

5. 1. Mode of Pacing
2. Rate
3. Capture function
4. Sensing function
5. What is the underlying rhythm?
6. What to do next?

6. No atrial spikes, each spike is followed by ventricular
activity so It is Ventricular pacing.
HR =80 bpm ,
no intrinsic ventricular beats , underlying rhythm is AF.

7. What to do next ?
1-sensing function should be assessed by using
the specific programmer
2-CHADsVaSc score is calculated to assess
the need of OAC

8. North American Society of Pacing and Electrophysiology/British Pacing and
Electrophysiology Group
Modes of pacing

9. Another Example of paced ECG

10. Mode :
Here , We can see 2 spikes.
One preceding the p wave and the other is preceding the
R wave and pacing is sequential
So it is a Dual Chamber Pacemaker.
Rate:
By Using Calibers from one atrial spike to the next one.
Capture:
Each atrial spike is followed by atrial depolarization
and each ventricular spike is followed by Vent. dep.
Sensing Function :
Couldn’t be assessed .. 100 % pacing

11. The underlying Rhythm :
It is probably Bi-nodal disease
What to do next?
Check the sensing function using the
programmer
By lowering both atrial and ventricular rates

12. So what about this strip?

13. What about it !!

14. There are pacemaker spikes followed by atrial activity .
There is association between each paced atrial activity and
Intrinsic ventricular activity
Mode is : AAI / DDD
Rate : AP-AP
Capture function of the atrium is appropriate
Sensing function : Atrial sensing couldn’t be assessed
Underlying Rhythm : SA nodal disease
What to do next?
Check the mode of pacing
If DDD you should test ventricular capture
And atrial sensing should be assessed in either modes

15. DDD
AS – VP
Capture : ventricular capture is appropriate
sensing : Atrial sensing function is appropriate
Underlying rhythm : AV nodal disease
What to do next? Check ventricular sensing by prolonging AV dela

17. Explain those beats

18. Capture beat: an intrinsic beat that captures
the ventricle
Fusion: a combination between intrinsic and
paced events
Pseudofusion: occurs when a spike falls on
an intrinsic beat

19. Paced beat
Fused beatIntrinsic
“capture” beat
Pseudo fusion

20. Mode : DDD
Capture :Appropriate in both chambers
Sensing Function : ok regarding both chambers

21. Explain this?
Hysteresis Function

22. Is their Anything wrong?

23. Take a Quick LOOK at V1

24. PaceMaker Malfunction

26. This strip was seen in a Holter Monitoring of
a patient who had a VVIR pacemaker and was
recently Complaining of dizziness while
playing Basket ball ?
Oversensing of myopotentials of pectoralis major muscle
Oversensing Leads to Underpacing

27. The pacemaker fails to generate an impulse
What is called “Failure of output”
Ventricular Oversensing

28. Undersensing

29. Failure of Capture
Spikes not followed by ventricular events
Pseudo fusion beats “3rd and 5th from lt”

30. Pacemaker mediated Tachycardia

32. PMT Initiated by atrial non capture

33. A strip is taken from a Patient with
VVI pacemaker while interrogating the device
Explain?
Magnet Mode Behavior
acting temporarily like VOO

34. Automatic Mode Switching

35. Any Questions ?

36. Thank You