Pacemaker overview

Pacemaker Overview

1. Pacemaker Overview

2. Indications for PacingIndications for Pacing
The normal & pathological ECG

3. Impulse Formation and
Conduction Disturbances

4. ““Normal Heart Rhythm” Normal Heart Rhythm”
(Function)(Function)

5. Sinoatrial
Node
Normal Heart Function

6. Normal Heart Function
Atrioventricular
Node

7. Bundle of
HIS
Normal Heart Function

8. Normal Heart Function
Left Bundle Branch
(LBB)
Anterior Fascicle
of LBB
Posterior Fascicle
of LBB
Right Bundle
Branch (RBB)

9. Normal Heart Function
Purkinje
Fibers

10. Normal Heart Function
Vent. Systole

11. Normal Heart Function
Vent. Diastole

12. The ECG

13. Normal Values
•PR Interval: 120 to 210 msec
•QRS Interval:80 to 110 msec

14. 60,000
Interval
= Heart Rate
Rate:Interval Relationship

15. The Rate isThe Rate is : ? ? : ? ?
Interval : 750 msecInterval : 750 msec
Rate:Interval Relationship

16. The Rate isThe Rate is : :
750750
Interval : 750 msecInterval : 750 msec
60,00060,000
80 bpm80 bpm
Rate:Interval Relationship

17. The interval is :The interval is :
5050
Rate : 50 bpmRate : 50 bpm
60,00060,000
1200 ms1200 ms
Rate:Interval Relationship

18. Interval (ms) 200 400 600 800 1000 1200 1400 1600

Rate (bpm/ppm) 300 150 100 75 60 50 43 37.5

Interval (ms) 200 400 600 800 1000 1200 1400 1600

Rate (bpm/ppm) 300 150 100 75 60 50 43 37.5

At a paper speed of 25mm/sec
Rate:Interval Relationship

19. 25 mm is 1 sec.
5 mm = 0.2 sec.
1 mm = 0.04
sec.
25 mm/second
Rate:Interval Relationship

20. ““Abnormal Heart Rhythm”Abnormal Heart Rhythm”
(Indications for Pacing)(Indications for Pacing)

21. Definitions....
•Bradycardia:R <60 bpm
•Tachycardia:R > 100 bpm
•Flutter: R > 250 bpm
•Fibrillation:R > 350 bpm

22. Pacemaker Indication Classifications
Class I – Conditions for which there is evidence and/or
general agreement that permanent pacemakers should be
implanted
Class II – Conditions for which permanent pacemakers are
frequently used but there is divergence of opinion with
respect to the necessity of their insertion
–Class IIa: Weight of evidence/opinion is in favor of
usefulness/efficacy
–Class IIb: Usefulness/efficacy is less well established
by evidence/opinion
Class III – Conditions for which there is general agreement
that pacemakers are unnecessary
JACC Vol. 31, no. 5 April 1998, 1175-1209

23. Pacemaker Indication Classifications
•Evidence supporting current recommendations are
ranked as levels A, B, and C:
–Level A: Data derived from multiple randomised clinical
trials involving a large number of individuals
–Level B: Data derived from a limited number of trials
involving comparatively small numbers of patients or
from well-designed data analysis of nonrandomised
studies or observational data registries
–Level C: Consensus of expert opinion was the primary
source of recommendation
JACC Vol. 31, no. 5 April 1998, 1175-1209

24. Sinus Node Dysfunction
•Sick Sinus Syndrome
•Sinus bradycardia
•Sinus arrest
•SA block
•Brady-tachy syndrome
•Chronotropic
incompetence (CI)

25. Class I Indications
•Sinus node dysfunction with documentedSinus node dysfunction with documented symptomatic sinus symptomatic sinus
bradycardiabradycardia
•Symptomatic chronotropic incompetence
Class II Indications
•Class IIa: Symptomatic patients with sinus node dysfunction
and with no clear association between symptoms and
bradycardia
•Class IIb: Chronic heart rate < 30 bpm in minimally
symptomatic patients while awake
Class III Indications
•Asymptomatic sinus node dysfunction
Sinus Node Dysfunction –
Indications for Pacemaker Implantation
JACC Vol. 31, no. 5 April 1998, 1175-1209

26. Sinus Node Dysfunction –
Sinus Bradycardia
•Persistent slow rate from the SA node. The
parameters from this waveform include:
–Rate = 55 bpm
–PR interval = 180 ms (0.18 seconds)

27. Sinus Node Dysfunction –
Sinus Arrest
•Failure of sinus node discharge resulting in the absence
of atrial depolarisation and periods of ventricular
asystole
–Rate = 75 bpm
–PR interval = 180 ms (0.18 seconds)
–2.8 second arrest
2.8-second arrest

28. 2.1-second pause
Sinus Node Dysfunction –
SA Exit Block
•Transient blockage of impulses from the SA
node
–Rate = 52 bpm
–PR interval = 180 ms (0.18 seconds)
–2.1-second pause

29. Sinus Node Dysfunction –
Brady-Tachy Syndrome
•Intermittent episodes of slow and fast rates
from the SA node or atria
–Rate during bradycardia = 43 bpm
–Rate during tachycardia = 130 bpm

30. Chronotropic Incompetence (CI)
Max
Rest
Heart
Rate
Time
Start
Activity
Stop
Activity
Quick
Unstable
Slow
Normal
CI

31. AV Block
•First-degree AV block
•Second-degree AV
block
–Mobitz types I and II
•Third-degree AV block

32. Class I Indications
•3rd

degree AV block associated with:
–Symptomatic bradycardia (including those from arrhythmias
and other medical conditions)
–Documented periods of asystole > 3 seconds
–Escape rate < 40 bpm in awake, symptom-free patients
–Post AV junction ablation
–Post-operative AV block not expected to resolve
•Second degree AV block regardless of type or site of
block, with associated symptomatic bradycardia
AV Block – Indications
JACC Vol.. 31, no. 5 April 1998, 1175-1209

33. AV Block – Indications
JACC Vol. 31, no. 5 April 1998, 1175-1209
Class II Indications
•Class IIa:
–Asymptomatic CHB with a ventricular rate > 40 bpm
–Asymptomatic Type II 2nd degree AV block
–Asymptomatic Type I 2nd

degree AV block within the His-Purkinje
system found incidentally at EP study
–First-degree AV block with symptoms suggestive of pacemaker
syndrome and documented alleviation of symptoms with temporary AV
pacing
•Class IIb:
–First degree AV block > 300 ms in patients with LV dysfunction in whom
a shorter AV interval results in haemodynamic improvement

34. AV Block – Indications
Class III Indications
•Asymptomatic 1st

degree AV block
•Asymptomatic Type I 2nd degree AV
block at supra-Hisian level
•AV block expected to resolve and
unlikely to recur (e.g., drug toxicity,
Lyme Disease)
JACC Vol. 31, no. 5 April 1998, 1175-1209

35. First-Degree AV Block
•AV conduction is delayed, and the PR
interval is prolonged (> 210 ms or 0.21
seconds)
–Rate = 79 bpm
–PR interval = 340 ms (0.34 seconds)
340 ms

36. Second-Degree AV Block –
Mobitz I (Wenckebach)
•Progressive prolongation of the PR interval until a
ventricular beat is dropped
–Ventricular rate = irregular
–Atrial rate = 90 bpm
–PR interval = progressively longer until a P-wave
fails to conduct
200 360 400
ms ms ms
No
QRS

37. Second-Degree AV
Block – Mobitz II
•Regularly dropped ventricular beats
–2:1 block (2 P waves to 1 QRS complex)
–Ventricular rate = 60 bpm
–Atrial rate = 120 bpm
P PQRS

38. Third-Degree AV Block
•No impulse conduction from the atria to the
ventricles
–Ventricular rate = 37 bpm
–Atrial rate = 130 bpm
–PR interval = variable

39. Bifascicular / Trifascicular Block

40. Class I Indications
•Intermittent 3rd

degree AV block
•Type II 2nd degree AV block
Class II Indications
•Class IIa:
–Syncope not proved to be due to AV block when other causes have been exluded,
specifically VT
–Prolonged HV interval ( >100 ms)
–Pacing-induced infra-Hisian block that is not physiological
•Class IIb: None
Class III Indications
•Asymptomatic fascicular block without AV block
•Asymptomatic fascicular block with 1st degree AV block
Bifascicular and Trifascicular
Block (Chronic) – Indications

JACC Vol. 31, no. 5 April 1998, 1175-1209

41. Bifascicular Block
Right bundle branch
block and left posterior
hemiblock

42. Bifascicular Block
Right bundle branch block
and left anterior hemiblock

43. Bifascicular Block
Complete left
bundle branch
block

44. Trifascicular Block
•Complete block in
the right bundle
branch and
complete or
incomplete block in
both divisions of the
left bundle branch

45. ECG Recording:
•Rate
•Rhythm
–regular or irregular?
–if irregular, is there a pattern?
(e.g. 2:1 or 3:1 block or Wenckebach)
•QRS-complexes? Width?
•P-waves? In what relation to QRS-complexes?
•PR-Interval with normal duration (120-210 ms) or
irregular? Continuously increasing P-R interval?

46. What is a Pacemaker?What is a Pacemaker?

47. What is a Pacemaker?What is a Pacemaker?
A Pacemaker System consists of a
Pulse Generator plus Lead (s)

48. What is a Pacemaker?

49. •Pulse generator: power
source or battery
•Leads or wires
•Cathode (negative
electrode)
•Anode (positive
electrode)
•Body tissue
IPG
Lead
Anode
Cathode
Implantable Pacemaker Systems Contain the
Following Components:

50. •Contains a battery
that provides the
energy for sending
electrical impulses
to the heart
•Houses the circuitry
that controls
pacemaker
operations
Circuitry
Battery
The Pulse Generator:

51. Battery
Connector
Hybrid
Telemetry antenna
Output capacitors
Reed (Magnet) switch
Clock
Defibrillation protection
Atrial connector
Ventricular connector
Resistors
Anatomy of a Pacemaker

52. Components of an IPG

53. What is a Pacemaker?

54. •Deliver electrical
impulses from the
pulse generator to
the heart
•Sense cardiac
depolarisation
Lead
Leads Are Insulated Wires That:

55. Conductor Tip Electrode Insulation Connector Pin
Pacing Lead Components
•Conductor
•Connector Pin
•Insulation
•Electrode

56. How do pacemakers work?How do pacemakers work?

57. How do pacemakers work?
•Modes and Codes
–NBG Code
–Mode Selection
–Indications for Pacing
–Pacing Modes
•Sensing & Pacing
•Pacemaker Timing
•Pacemaker Therapies (Operation) &
Diagnostics

58. Modes and CodesModes and Codes

59. NBG Code
I
Chamber
Paced
II
Chamber
Sensed
III
Response
to Sensing
IV
Programmable
Functions/Rate
Modulation
V
Antitachy
Function(s)
V: VentricleV: VentricleT: Triggered
P: Simple
programmable
P: Pace
A: AtriumA: Atrium I: Inhibited
M: Multi-
programmable
S: Shock
D: Dual (A+V)D: Dual (A+V)D: Dual (T+I)C: CommunicatingD: Dual (P+S)
O: None O: None O: None R: Rate modulatingO: None
S: Single
(A or V)
S: Single
(A or V)
O: None

60. Mode Selection for Optimal Mode Selection for Optimal
Pacing TherapyPacing Therapy

61. Providing Optimal Pacing
Therapy
•Heart rate increase
•Stroke volume maximisation
•Atrial based pacing
•Normal ventricular activation sequence
•(Patient outcomes and costs if optimal
pacing therapy/mode is not chosen)

62. Cardiac OutputCardiac Output
Cardiac Output (l/min)=
Heart Rate x Stroke Volume

63. Heart Rate
x
x
x
x
SV
x HR
Age 65-80 (N=16)
130
120
110
100
90
80
70
H
e
a
r
t

R
a
t
e

(
B
P
M
)
S
t
r
o
k
e

V
o
lu
m
e

(
m
L
/
M
in
)
Cardiac Output (L/Min)
Rodehefer RJ, Circ.; 69:203, 1984.
67891011121314151613 1718
70
80
90
100
110
120
130
140
150
160
x

64. Proven Benefits of Atrial Based
Pacing
Study Results
Higano et al. 1990
Gallik et al. 1994
Santini et al. 1991
Rosenqvist et al. 1991
Sulke et al. 1992
Improved cardiac index during low level
exercise (where most patient activity occurs)
Increase in LV filling
30% increase in resting cardiac output
Decrease in pulmonary wedge pressure
Increase in resting cardiac output
Increase in resting cardiac output, especially
in patients with poor LV function
Decreased incidence of mitral and tricuspid
valve regurgitation

65. Proven Benefits of Atrial Based
Pacing
Study Results
Rosenquist 1988
Santini 1990
Stangl 1990
Zanini 1990
Less atrial fibrillation (AF), less CHF, improved
survival after 4 years compared to VVI
Less AF, improved survival after 5 years average
Less AF, improved survival after 5 years
compared to VVI
Suppression of atrial dysrhythmias
Improved morbidity (less AF, CHF, embolic
events) after 3 plus uears, compared to VVI

66. Patient Mode Preference
DDDR 59%
DDIR 13%
Any Dual 9%
No Preference 9%
DDD 5%
VVIR 5%
Sulke N, et al. J AM Coll Cardiol; 17(3):696-706, 1991

67. Optimal Pacing Mode (BPEG)
•Sinus Node Disease -AAI (R)
•AVB -DDD
•SND + AVB -DDDR + DDIR
•Chronic AF + AVB -VVI (R)
•CSS / MVVS -DDI

68. Alternative Pacing Mode
•Sinus Node Disease -AAI
•AVB -VDD
•SND + AVB -DDD + DDI
•Chronic AF + AVB -VVI
•CSS -DDD / VVI
•MVVS -DDD

69. Inappropriate Pacing Mode
•Sinus Node Disease -VVI + VDD
•AVB -AAI + DDI
•SND + AVB -AAI + VVI
•Chronic AF + AVB -AAI/DDD/VDD
•CSS -AAI+VDD
•MVVS -AAI/VVI/VDD

70. Mode Selection Decision Tree
DDIR with
SV PVARP
DDDR with
MS
N
VVI
VVIR
Are they
chronic?
Y
Y N
DDD, VDD
DDDR
DDDR
Y N
Is AV conduction
intact?
Is SA node function
presently adequate?
Symptomatic
bradycardia
Are atrial
tachyarrhythmias
present?
Is SA node function
presently adequate?
Is AV conduction
intact?
Y
Y
N
AAIR
DDDR
DDD, DDI
with RDR
N N(SSS)
(CSS,
VVS)
N

71. Summary of Pacemaker Indications
•Sinus node dysfunction
•AV block (Congenital, acquired, surgical)
•Bifascicular and trifascicular block
•Hypersensitive Carotid Sinus Syndrome (CSS)
•[ Malignant Vasovagal Syncope (MVVS) ]
•Pacing after cardiac transplantation
•Heart Failure / HOCM / AF
•( AHA/ACC and BPEG indications )

72. Pacing ModesPacing Modes

73. Output circuit
VVI
AMP
Ventricular Demand
Pacing Modes

74. Programmed lower rate 50 mm/s
VVI
Pacing Modes

75. Output circuit
VVIR
AMP
Sensor
Ventricular Demand
Pacing Modes

76. Programmed lower rate 50 mm/s
Sensor indicated
rate
VVIR
Pacing Modes

77. Programmed lower rate 50 mm/s
Sensor indicated
rate
VVIR
Pacing Modes

78. Output circuit
AAI
AMP
Atrial Demand
Pacing Modes

79. Programmed lower rate 50 mm/s
AAI
Pacing Modes

80. Output circuit
AAIR
AMP
Atrial Demand
Sensor
Pacing Modes

81. Programmed lower rate 50 mm/s
AAIR
Sensor indicated rate
Pacing Modes

82. Output circuit
VAT
AMP
Atrial Synchronised
Pacing Modes

83. Output circuit
DVI
AMP
A-V Sequential
Output circuit
Output circuit
VDD
AMP
AMP
Pacing Modes

84. = Refract.Sensing
= Blanking
= Refract.periode= Stimulatie
= Sensing
V
A
Pacing Modes
VDD

85. Output circuit
DVI
AMP
A-V Sequential
Output circuit
Pacing Modes

86. Programmed lower rate 50 mm/s
DVI
Pacing Modes

87. Output circuit
DVIR
AMP
A-V Sequential
Output circuit
Sensor
Pacing Modes

88. Output circuit
DDI(R)
AMP
Output circuit
Timing & Control
AMP
A-V UniversalSensor
Pacing Modes

89. Output circuit
DVI
AMP
A-V Sequential
Output circuit
Output circuit
DDD
AMP
A-V Universal
Output circuit
Timing & Control
AMP
Pacing Modes

90. Output circuit
DVI
AMP
A-V Sequential
Output circuit
Output circuit
DDDR
AMP
A-V Universal
Output circuit
Timing & Control
AMP
Sensor
Pacing Modes

91. Pacing Modes - Summary
Output circuit
VAT
AMP
Atrial Synchronised
Output circuit
AAI
AMP
Atrial Demand
Output circuit
DVI
AMP
A-V Sequential
Output circuit
Output circuit
VDD
AMP
Atrial synchronised
Ventricular Inhibited
AMP
Output circuit
DDD
AMP
A-V Universal
Output circuit
Timing & Control
AMP
Output circuit
VVI
AMP
Ventricular Demand