basic

1. pacemaker
chairperson: dr sujoy sarkar
By: dr janardan mondal

3. •pacemaker?

4. History of pacemaker

5. Implantable pacemaker…

6. Methods of pacing
1)Percussive pacing
2)Transcutaneous pacing
3)Epicardial pacing
4)Transvenous pacing

7. METHODS OF PACING…………
percussive transcutaneous

8. CONT…….
EPICARDIAL PACING…. TRANSVENOUS PACING….

9. TRANSVENOUS PACING
It Involves Threading An Eletrode Catheter Through A Vein Into The Right
Atrium Or Rt Ventricle.
FIVE DIFFERENT VEINS CAN BE USED…
Antecubital Vein
Femoral Vein
Subclavian Vein
Internal Jugular Vein
External Jugular Vein

10. CONT……
subCLAVICULAR PACEMAKER….

12. TYPES OF PACEMAKER
TEMPORARY PACEMAKER….
PERMANENT PACEMAKER….

13. THE PACEMAKER SYSTEM
A simple electrical circuit consisting of….
PULSE GENERATOR
PACING LEAD

14. Pacing pulse generator

15. Cont..
• Adv. Of Lithium iodide battery:
1) High energy density
2) Long shelf life
3) Internal self discharge
4) Predictable characteristic that allow early warning of battery depletion
• LIFE SPAN--- SCP-----7 to 12 yrs
DCP---- 6 to 10 yrs
• Most pacemaker generate 2.8v at the beginning of life &
end @ 2.1 to 2.4v.

16. PACING LEAD SYSTEM
BIPOLAR UNIPOLAR

18. Pacing site
ATRIAL VENTRICULAR
Single site Rt atrial appendages RV apex
Prior cardiac surgery Atrial septum/Lat wall His bundle
Dual site Rt atrial appendages RV apex
Coronary sinus ostium LV through coronary sinus

20. INTRACRADIAC ELECTROGRAM
• An EGM displays the electrical
potential difference b2n two
points in space over time.
• UNIPOLAR—one in the heart &
remote in the can.
• BIPOLAR—tip to ring.
• AMPLITUDE—atrial 1 to 5 mv
• ventricle 5 to 20mv
• FREQUENCY same
• 5 to 50 Hz

21. PACING & SENSING?
PACING---
When the delivered pacemaker impulse results in depolarisation of
the corresponding cardiac chamber, it indicates successful pacing or capture.
SENSING---
Pacemakers also detect & respond to the intrinsic cardiac activity
and this is known as sensing. When an intrinsic event is sensed, the
pacemaker does not initiate the electrical impulse in the same
chamber(inhibited) to prevent interference with the cardiac activity.

22. Sensing & detection

23. Single or dual chamber pacemaker
SCP---It has only one lead,either in the rt atrium or in the rt
ventricle. A single chamber atrial pacemaker can therefore
have either As or Ap..and ventricle has Vs or Vp.
DCP---It has 2 leads, one in the rt atrium & the other in the rt
ventricle.DCP can have any of the following 4 configuration…
1)AsVs
2)AsVp
3)ApVs
4)ApVp

25. CODES…
 DDD
Pace: Atrium and Ventricle
Sense: Atrium and Ventricle
Response: Inhibited and Triggered
This is fully automatic or universal pacemaker
 VVI
Pace: Ventricle
Sense: Ventricle
Response: Inhibited
Ventricular pacing, ventricular sensing, inhibited
response to sensed QRS complexes

26. CONT…
Pacing Modes Description
Asynchronous
 AOO Atrial pacing, no
sensing
 VOO Ventricular pacing,no
sensing
 DOO Atrial and ventricular
pacing, no sensing

27. PACINGMODES
Pacing Modes Description
Synchronous
 AAI Atrial pacing, atrial sensing,
inhibited response to sensed P wave
 VVI Ventricular pacing, ventricular
sensing, inhibited response to sensed
QRS complexes
 DVI Atrial and ventricular pacing,
ventricular sensing; both atrial and
ventricular pacing are inhibited if a
spontaneous ventricular
depolarization is sensed.

28. Pacing Modes Description
Universal
 DDD Both chambers are paced and sensed; inhibited
response of the pacing stimuli to
sensed events in their respective
chamber;triggered
response to send atrial activity
to allow for rate – responsive
ventricular pacing.

29. Pacemaker settings…
Rate
Output
Sensitivity

30. rate
The rate setting depend on the physiological needs of the patient, but
it is generally maintained between 60-80 beats/min.
 If the pacemaker is operating in dual-chamber mode, the ventricular
control rate also regulate the atrial rate.

31. output
 The point at which depolarization occurs is termed threshold and is
indicated by a myocardial response to the pacing stimulus (capture).
 It is the amount of electrical current (measured in milliamperes
[mA]) that is delivered to the heart to initiate depolarization.

32. SENSITIVITY
The sensitivity control regulates the ability of the pacemaker to the
heart’s intrinsic electrical activity.
 Sensitivity is measured in millivolts (mV) and determines the size of
the intracardiac signal that generator will recognize.

33. The VVI timing cycle consists of a defined lower rate limit and a ventricular refractory
period (VRP, represented by rectangles). When the ventricular escape interval (VEI)
from the ventricular sensed event of 1000 milliseconds is completed, a paced event
occurs. Because no ventricular sensed event occurs within 1000 milliseconds after the
paced event, a second ventricular paced event occurs. Because a ventricular sensed
event occurs 800 milliseconds later, a ventricular paced event does not occur. A VRP
begins with any sensed or paced ventricular activity.

34. The AAI timing cycle consists of a defined lower rate limit and
an atrial refractory period (ARP, represented by rectangles). When the atrial escape
interval (AEI) from the atrial sensed event of 1000 milliseconds is completed, a
paced event occurs. Because no atrial sensed event occurs within 1000 milliseconds
after the paced event, a second atrial paced event occurs. Because an atrial sensed
event occurs 800 ms later, an atrial paced event does not occur. An ARP begins
with any sensed or paced atrial activity.

35. The timing cycle in DDD consists of a lower rate limit, an AV interval, a ventricular refractory period, a
PVARP, and an upper rate limit. Because an intrinsic atrial event occurs and is followed by an intrinsic
ventricular event within the AV interval, no ventricular pacing occurs in the first beat. In ventricular-based
timing, the time from a ventricular paced or sensed event to the next atrial paced event is called the atrial
escape interval (AEI), which is the lower rate limit interval minus the AV interval. Because no intrinsic atrial
event occurs, a paced atrial event occurs. Because no intrinsic ventricular event occurs after this atrial paced
event within the AV interval, a ventricular paced event occurs. Following this ventricular paced event an atrial
paced event of 800 milliseconds occurs within the AEI. However, AV conduction follows this atrial paced event.
The final event is an atrial intrinsic event that is not followed by an intrinsic ventricular event within the AV
interval. Hence the intrinsic atrial event is “tracked” and followed by a paced ventricular event. If intrinsic atrial
and ventricular activity occurs before the lower rate limit times out, both channels are inhibited and no pacing
occurs. In the absence of intrinsic atrial and ventricular activity, AV sequential pacing occurs (first cycle). If no
atrial activity is sensed before the VA interval is completed, an atrial pacing artifact is delivered, which initiates
the AV interval. If intrinsic ventricular activity occurs before termination of the AV interval, ventricular output
from the pacemaker is inhibited, that is, atrial pacing (second cycle). If a P wave is sensed before the VA interval
is completed, output from the atrial channel is inhibited. The AV interval is initiated, and if no ventricular
activity is sensed before the AV interval terminates, a ventricular pacing artifact is delivered, that is, P-
synchronous pacing (third cycle).

36. PACINGARTIFACT
The pacing artifact is the spike that is seen on the ECG tracing as the
pacing stimulus is delivered to the heart.
 A P wave is visible after the pacing artifact if atrium is being paced.

37. CONT…..

38. Pacemaker complication
• Pneumothorax
• Cardiac perforation
• Hematoma
• Venous occlusion
• Infection
• Lead dislodgement
• Diaphragmatic stimulation
• Twiddler syndrome
• Pacemaker syndrome

39. Pacemaker syndrome
• Cause—1)loss of AV synchrony
• 2)presence of ventriculoatrial contraction
• Atrial contraction against closed AV valves----leads to increased in Jugular &
pulmonary venous pressure..
• C/F --- neck pulsation,fatigue,palpitation,cough,chest fullness,choking
sensation,orthopnoea,syncope,confusion,altered mental state etc..

40. PACEMAKER MEDIATED TACHYCARDIA
• In patient with intact VA
conduction,a premature
ventricular contraction may result
in retrograde conduction to the
atria,which,if outside the PVARP,
is sensed & followed by
ventricular pacing after the
programmed AV interval.
• The paced ventricular event will
again be followed by VA
conduction,resulting in endless
loop tachycardia..

41. PMT

42. Troubleshooting
IN TPI

43. FAILURE TO FIRE
• Failure of the pacemaker deliver the pacing stimulus results in the
disappearance of the pacing artifact, even though the patient’s
intrinsic rate is less than the set rate on the pacer. This can occur
either intermittently or continuously and can be attributed to failure
of the pulse generator or its battery.

44. CONT….

45. CONT…
CAUSES:
Loose head hookups
Dead battery
Malfunctioning pulse generator

46. Rx…..
INTERVENTIONS
 Secure lead hookups
 Replace battery
 Replace pulse generator

47. FAILURE TO CAPTURE
 If the pacing stimulus fires but fails to initiate a myocardial
depolarization, a pacing artifact will be present but will not be
followed by the expected P wave or QRS complex, depending on the
chamber being paced.

48. CONT…

49. FAILURE TO CAPTURE
CAUSES
 Pacemaker output too low
 Catheter dislodged
 Loose connections

50. RX….
INTEREVENTIONS:
Increase pacemaker output
Reposition catheter
Secure all connections

51. FAILURE TO SENSING
UNDERSENSING
In it pacemaker fires at wrong times or for the wrong reasons (help
being given when none is needed).
OVERSENSING
In it pacemaker fires incorrectly senses depolarization and refuses to
fire when it should (won’t pace when the patient actually needs it).

52. UNDERSENSING
• CAUSES---
• Scar formation at the tissue lead
interface.
• Dyselectrolytemia
• Infarction
• Ischaemia
• Lead fracture
• Insulation breaks
• cardioversion

53. oversensing
• SCP---oversensing leads to inhibition of the pacing channel & causes
inappropriate pauses
• DCP— it elicits either inappropriate inhibition or triggering,depending
on the channel in which oversensing occurs & the programmed pacing
mode.

55. Crosstalk?
• Atrial channel output can be sensed in the ventricular channel as a far
field signal & inhibit the ventricular pacing output. This is k/a crosstalk,
more common in unipolar system.
• Rx----there is programmable ventricular blanking period (51 to
150ms)after atrial pacing,during which ventricular channel is refractory.

56. RX…
INTERVENTION
 Correct the sensitivity setting
 Replace battery
 Secure all connections
 Correct the underlying cause

57. PREVENTIONOF MALFUNTION
 Continuous ECG monitoring is essential to facilitate prompt
recognition and appropriate intervention for pacemaker
malfunction.
 The temporary pacing lead and bridging cable must be
properly secured to the body with tape to prevent the
accidental displacement of the electrode, which can result in
failure to pace or sense.
 The external pulse generator can be secured to the patient’s
waist with a strap

58. CONT..
 For the patient on a regimen of bed rest, the pulse generator can
be suspended with twill tape from an intravenous (IV) pole mounted
overhead on the ceiling.
 This not only will prevent tension on the lead while the patient is
moved (given adequate length of bridging cable) but will also
alleviate the possibility of accidental dropping of the pulse
generator.

59. Follow up…
 Four primary areas:
 Assessment and prevention of pacemaker malfunction,
 Protection against micro shock,
 Surveillance for complications such as infection
 Patient education.

60. MICROSHOck PROTECTION..
 It is important to be aware of all sources of EMI within the critical
care environment that could interfere with the pacemaker’s
function. Sources of EMI in the clinical area include electrocautery,
defibrillation current, radiation therapy, magnetic resonance imaging
devices, and transcutaneous electrical nerve stimulation (TENS)
units.

61. Cont…
In most cases, if EMI is suspected of precipitating pacemaker
malfunction, converting to asynchronous mode (fixed rate) will
maintain pacing until the cause of the EMI is removed.
 The pacing electrode provides a direct, low resistance path to the
heart, the nurse takes special care while handling the external
components of the pacing system to avoid conducting stray
electrical current from other equipment

62. INFECTION
• Infection at the lead site is a rare but serious complication
associated with temporary pacemakers.
• The (sites) is carefully inspected for purulent drainage, erythema,
and edema, and the patient is observed for the signs of systemic
infection.

63. CONT….
 Site care is performed according to institution’s protocol. Although most
infections remain localized, endocarditis can occur in patients with
endocardial pacing leads.
 A less common complication associated with transvenous pacing is
myocardial perforation, which can result in rhythmic hiccoughs or
cardiac tamponade.

64. Drug interaction
• FLECAINIDE--- may increase pacing thresholds.
• B-blockers----- prolong AV conduction & increased rt ventricular . .
. pacing.
• HYPERKALEMIA

65. PERIOPERATIVE MANAGEMENT
Require preoperative determination of:
1)pacemaker dependency
2)device model
3)type of lead
4)plan to use electrocautery
• Surgery below the umbilicus have a lower risk for
electromagnetic interference..

66. Role of magnet

67. Use of magnet
Locate on the patient where the pacemaker has been implanted.
1. Hook patient up for 12 lead EKG.
2. Set the cart to run a rhythm strip displaying leads II, V1, and V5.
3. Begin the rhythm strip . Let the strip run until it has printed one page.
4. While strip is still running, place magnet over the pacemaker area as . .
described below:
A. Horseshoe magnet- place the feet of the magnet directly onto
the pacemaker.

68. B
. Doughnut magnet- Lay the magnet flat
and place the edge of the magnet on the
pacemaker. DO NOT center the hole of the
magnet over the pacemaker. Just the edge.
5. Observe the tracing. Draw a line on the
tracing where you placed the
magnet in place. On the tracing after the
magnet is placed you should
observe the following:
a. Five (5) beats at 90 with PR interval of
approximately 100ms. The last
beat energy is halved.
b. Then the rhythm should change to the
programmed rate. Depending on
what rate it actually is will determine the
expected life of the pacemaker.
6. Continue to run one page after the magnet
has been placed on the
pacemaker.
7. If you should not see the rate change on the
tracing, you may need to
reposition the magnet until the five beats at 90
appear.