1. Case Studies
St. Jude Medical

2. Single Chamber ECG Analysis
Programmed Parameters
Mode………………………………………….. VVI
Base Rate……………………………………… ppm
Magnet Response…………………….. Battery Test
Hysteresis Rate………………………………… Off ppm
T Temporary programmed value
1.0 Second
7 Mar :20

3. Single Chamber ECG Analysis
Answer ECG #1
VVI
Normal Capture and Sensing

4. Single Chamber ECG Analysis

5. Single Chamber ECG Analysis
Answer ECG #2
VVI
Normal Capture and Sensing with initiation of Hysteresis

6. Single Chamber ECG Analysis

7. Single Chamber ECG Analysis
Answer ECG #3
VVI
Loss of Ventricular Sensing

8. Single Chamber ECG Analysis
1.0 Second

9. Single Chamber ECG Analysis

10. Single Chamber ECG Analysis
Answer ECG #4
VVI
Normal Capture and Sensing

11. Single Chamber ECG Analysis

12. Single Chamber ECG Analysis

13. Single Chamber ECG Analysis
Answer ECG #5
VVI
Normal Capture
Ventricular Undersensing

14. Single Chamber ECG Analysis

15. Single Chamber ECG Analysis

16. Single Chamber ECG Analysis
Answer ECG #6
VVI
Loss of Ventricular Capture
Normal Sensing

17. Dual Chamber ECG Analysis
Base Rate 60 ppm
MTR 120 ppm
AVD 200 ms
PVARP 250 ms

18. Dual Chamber ECG Analysis
Answer ECG #1
Loss of Atrial Capture
Normal Atrial Sensing
Normal Ventricular Capture
Ventricular Sensing Unknown

19. Dual Chamber ECG Analysis
Base Rate 60 ppm
MTR 120 ppm
AV 200 ms
PV 150 ms
Min. PV ms
PVARP 250 ms

20. Dual Chamber ECG Analysis
Answer ECG #2
Normal Atrial Capture
Normal Atrial Sensing
Normal Ventricular Capture
Ventricular Sensing Unknown

21. Dual Chamber ECG Analysis
Base Rate 60 ppm
MTR 120 ppm
AV 200 ms
PV 150 ms
PVARP 250 ms

22. Dual Chamber ECG Analysis
Answer ECG #3
Normal Atrial Capture
Possible Psuedofusion on 4th atrial output
Atrial Sensing Unknown
Loss of Ventricular Capture
Normal Ventricular Sensing
Functional Loss of Ventricular Sensing

23. Dual Chamber ECG Analysis
Base Rate 60 ppm
MTR 120 ppm
AV 200 ms
PV 200 ms
PVARP 250 ms

24. Dual Chamber ECG Analysis
Answer ECG #4
Normal Atrial Capture
Atrial fusion on 3rd atrial output
Normal Atrial Sensing
Normal Ventricular Capture
Normal Ventricular Sensing

25. Dual Chamber ECG Analysis
Base Rate 60 ppm
MTR 120 ppm
AV 200 ms
PV 200 ms
PVARP 250 ms

26. Dual Chamber ECG Analysis
Answer ECG #5
Normal Atrial Capture
Atrial Sensing Unknown
Normal Ventricular Capture
Fusion on 2nd ventricular output
Normal Ventricular Sensing

27. Dual Chamber ECG Analysis
Base Rate 60 ppm
MTR 120 ppm
AV 200 ms
PV 200 ms
PVARP 250 ms

28. Dual Chamber ECG Analysis
Answer ECG #6
Normal Atrial Capture
Atrial Sensing Unknown
Normal Ventricular Capture
Fusion on 2nd ventricular output
Ventricular Sensing Unknown

29. Dual Chamber ECG Analysis
Base Rate 60 ppm
MTR 120 ppm
AV 200 ms
PV 200 ms
PVARP 250 ms

30. Dual Chamber ECG Analysis
Answer ECG #7
Normal Atrial Capture
Normal Atrial Sensing
Normal Ventricular Capture
Normal Ventricular Sensing

31. Dual Chamber ECG Analysis
Base Rate 60 ppm
MTR 120 ppm
AV 200 ms
PV 200 ms
PVARP 250 ms

32. Dual Chamber ECG Analysis
Answer ECG #8
Normal Atrial Capture with one beat showing functional loss of atrial capture
Atrial Undersensing
Normal Ventricular Capture
Ventricular Sensing Unknown

33. Dual Chamber ECG Analysis
Base Rate 60 ppm
MTR 120 ppm
AV 200 ms
PV 200 ms
PVARP 250 ms

34. Dual Chamber ECG Analysis
Answer ECG #9
Normal Atrial Capture
Normal Atrial Sensing
Normal Ventricular Capture
Normal Ventricular Sensing

35. Dual Chamber ECG Analysis
Base Rate 60 ppm
MTR 120 ppm
AV 200 ms
PV 200 ms
PVARP 250 ms

36. Dual Chamber ECG Analysis
Answer ECG #10
Normal Atrial Capture
Normal Atrial Sensing
Normal Ventricular Capture with two beats of functional loss of capture
Ventricular Undersensing

37. Dual Chamber ECG Analysis
Base Rate 60 ppm
MTR 120 ppm
AV 150 ms
PV 150 ms
PVARP 250 ms

38. Dual Chamber ECG Analysis
Answer ECG #11
Atrial Capture Unknown
Normal Atrial Sensing
Normal Ventricular Capture
Ventricular Sensing Unknown

39. Dual Chamber ECG Analysis
Base Rate 60 ppm
MTR 120 ppm
AV 200 ms
PV 150 ms
Min. PV ms
PVARP 250 ms

40. Dual Chamber ECG Analysis
Answer ECG #12
Normal Atrial Capture
Normal Atrial Sensing
Normal Ventricular Capture
Ventricular Sensing Unknown
Initiation of a Pacemaker Mediated Tachycardia (PMT) with following a PVC

41. Dual Chamber ECG Analysis
Base Rate 60 ppm
MTR 120 ppm
AV 200 ms
PV 150 ms
Min. PV ms
PVARP 250 ms

42. Dual Chamber ECG Analysis
Answer ECG #13
Loss of Atrial Capture initiating a Pacemaker Mediated Tachycardia (PMT)
Normal Atrial Sensing
Normal Ventricular Capture
Ventricular Sensing Unknown

43. Dual Chamber ECG Analysis
Base Rate 60 ppm
MTR 120 ppm
AV 200 ms
PV 150 ms
Min. PV ms
PVARP 250 ms

44. Dual Chamber ECG Analysis
Answer ECG #14
Normal Atrial Capture
Atrial Sensing Unknown
Normal Ventricular Capture
Normal Ventricular Sensing
The retrograde P-wave after the PVC is not seen because it falls in PVARP just like it should

45. ICD ECG Analysis
ECG #1

46. ICD ECG Analysis
ECG #1

47. ICD ECG Analysis Answer ECG #1 T-Wave sensing longer decay delay
Threshold start higher

48. Twiddler‘s Syndrome
Presented with left hemi-diaphragmatic stimulation from atrial lead

49. Twiddler‘s Syndrome Courtesy of Dr. F. Venditti, Lahey Clinic, MA`
Operative Color Picture- Twiddler’s Syndrome
Courtesy of Dr. Ferdinand Venditti, Chief of Cardiology at the Lahey Clinic. Twiddler’s syndrome with lead twisted in the pocket. While the general advise is to never hold a lead with mechanical forceps or a hemostat as this may damage the lead, when the lead is as twisted as this one, it should not be re-advanced into the patient. Hence, it is being held with an instrument.
This lead has been subjected to excessive stresses such that even if straightened and re-advanced into the patient, it is likely to have mechanical problems at some later date. Hence, if the pocket has to be entered due to Twiddler’s Syndrome, the lead should be removed and replaced with a new lead.
Slide Series: X-Ray-99.ppt
Courtesy of Dr. F. Venditti, Lahey Clinic, MA` 63

50. Rib-Clavicle Crush
Rib-Clavicle Crush - Dual Unipolar DDD pacing - X-Ray
These are cone down views of a PA chest x-ray obtained just prior to discharge after the pacing system was implanted and again 22 months later when the patient presented with an open circuit on the atrial channel. The measured lead impedance as > 1990 ohms. Both leads had been implanted via subclavian venipuncture using a relativiely medial approach. While one was totally transected, the other appeared to be functioning normally. However, as both leads were literally in the same tract and hence, both were subjected to similar external forces, both leads were replaced with the pulse generator moved to the other side of the body.
In this patient, a diligent search had been made for the cephalic vein at the original implantation. Only when it could not be found was the subclavian approach utilized. At the revision procedure, the patient did not have a detectable cephalic vein in the right antecubital fossae and there was only a thin whisp of a vein on venography. Hence, subclavian venipuncture was again utilized. This antedated the appreciation of accessing the axillary vein although in the revision procedure, attempts were made to stay as lateral as possible.
Slide Series: X-Ray-99.ppt

51. Rib-Clavicle Crush
Rib-Clavicle Crush - Scanning EM of Internal insulation
The same lead shown in the X-ray and the gross picture of the extracted lead was dissected in the Reliability lab. The external conductor was carefully removed leaving the internal insulation and internal conductor coil. The insulation demonstrates abrupt breaks which expose the internal (proximal) conductor to the distal conductor. Make-break contact between these two conductors generated voltage transients leading to episodes of oversensing. Persistent contact may result in a total short circuit and noncapture despite the presence of an output. The measured impedance will be < 250 ohms.
Based on this scanning electron microscopic picture, the insulation is cracked through and through in multiple places from external stress on the lead. The insulation between these cracks is totally normal.
Slide Series: X-Ray-99.ppt

52. Rib-Clavicle Crush Original lead damaged by rib-clavicle crush.
New lead placed via cephalic vein cutdown

53. Myopotential Oversensing

54. Evaluation of Oversensing
Reproduce while monitoring EGM / Event Markers
Try to eliminate with reduced sensitivity
Provocative maneuvers

55. Ventricular Fusion

56. Ventricular Pseudofusion

57. Loss of Capture due to Intrinsic Rise in Capture Threshold
Metabolic abnormalities
Hyperkalemia ( ­ K+ )
Congestive Heart Failure
Changes in time of day
sleep >> wake
Exercise and heart rate
Pharmacologic agents
Flecainide
Bipolar VVI with 2nd degree Wenckebach exit-block due to hyperkalemia (serum K 7.3 mEq/L). Upon correction of elevated potassium level, capture threshold was ms

58. Hysteresis Slower rate and pauses ONLY follow native beats
First escape cycle followed by pacing at higher rate
Management
Education
Disable if causing problems
Programming
Base Rate: ppm
Hysteresis Rate: ppm