3. DEFINITION
Pacemakers are the electronic devices that can be used to initiate
the heartbeat when the heart’s intrinsic electrical system cannot
effectively generate a rate adequate to support cardiac output
4. INDICATION
Heart rate is slow, causing hemodynamic compromise
Sick sinus syndrome
Sinus bradycardia or atrial fibrillation with slow heart rate response
(generally < 40bpm)
Heart block
3rd degree
2nd degree type 2 (Mobitz)
Malignant Tachyarrhythmia caused by bradycardia
Torsades de Pointes
5. TYPES OF PACEMAKERS
Single chamber
Dual chamber
Biventricular
Temporary pacemaker
Permanent pacemaker
7. FUNCTIONS OF PACEMAKER
Sensing
The device ‘sees’ a native heart beat
Expressed in Millivolts (mV).
Pacing
The device delivers a shock to stimulate a heart beat
Expressed in Milliamperes(mA)
8. COMPONENTS
The Pacemaker System is a simple electrical circuit consisting of
PULSE GENERATOR PACING LEAD
9. PULSE GENERATOR
The pulse generator is designed to generate an electrical current
that travels through pacing lead and exits through electrode that is in
direct contact with the heart. This electrical current initiates a
myocardial depolarization.
The power source for a temporary external pulse generator is
standard 9-volt alkaline battery inserted into the generator
10. PACING LEAD
Standard pacing leads are bipolar
Single use.
3 to 6 Fr in diameter
Usually placed in RV apex
Some have inflatable balloon between electrodes
-which allows the lead to float & follow circulation.
-once it reaches RV , deflate it to prevent entering pulmonary
artery.
13. TRANSVENOUS PACING
Transvenous pacing
It involves threading an electrode catheter through a vein
into the right atrium or right ventricle.
Four venous access , that can be used.
Femoral approach
Subclavian
Internal jugular
External jugular
14. PACEMAKER TERMINOLOGY
Fixed rate (Asynchronous)
It delivers an electrical impulse at a present fixed rate to the
heart and functions independently of cardiac activity.
Demand (synchronous)
The pulse generator delivers artificial stimulus only when
needed or on demand and therefore does not compete with
patient’s rhythm
15. Dual chamber
• Dual-chamber pacemakers have two leads, placed in the right
atrium and right ventricle.
Single chamber
• Single-chamber pacemakers may be atrial or ventricular.
• Atrial pacemakers are used where slow heart rate is due only to
sinoatrial disease, i.e. where conduction between the atria and
ventricles is intact.
16. MEDTRONIC SINGLE CHAMBER TEMPORORY
PACEMAKER
1 Lead Terminals
2 Green LED – Sensed Event
3 Yellow LED – Paced Event
4 Pulse Output Amplitude (0.3 … 12 V)
5 Mode Selector
6 Button to activate high-rate stimulation
7 Sensitivity Control
8 Stimulation Rate, ppm (Basic Rate)
9 Red LED – Errors, Low Battery
10 Cover
11 Ridge for Arm Strap
17. Dials of Medtronic pacemaker
Sensitivity
(1 – 20 mV, f=asynchronous
Rate (30-180 ppm)
Pulse Amplitude (0.3 – 12 Volts)
Mode: OFF / VVI / High Rate
19. OUTPUT
It is the amount of electrical current that is delivered to the heart
to initiate depolarization.
Myocardial response to the pacing stimulus is called capture.
Measured in milliamperes [mA]
0.3-12 Volts
LED illuminates YELLOW when pacing
pulse delivered.
20. SENSITIVITY
The sensitivity control regulates the ability of the
pacemaker to the heart’s intrinsic electrical activity.
Sensitivity is measured in millivolts (mV)
Sense LED illuminates GREEN when intrinsic activity
sensed.
22. MODE
Off
VVI: (or AAI) without sound
VVI Beep: (or AAI) audible signal during sensing and pacing
(two different tones)
X2: stimulation delivered at twice the basic rate when High
Rate button depressed
X4: stimulation delivered at four times the basic rate when
High Rate button depressed
23. VVI explained
A VVI pacemaker
Paces the ventricle
Senses the ventricle
In response to a sensed event it INHIBITS the pacing
response
(So if it doesn’t SENSE a native heart beat in a specified
period, it will deliver a pace.)
24. Preparation for the procedure
Record patient’s baseline ECG & vitals .
Explain the procedure & get an informed consent.
Skin preparation
Fluroscopy
Keep under close ECG monitoring
Crashcart to keep aside.
Radiation shields(lead aprons)
25. Gather Equipment
Pacing lead , pacer box & connection cable
Skin preparation solution
Sterile Gloves , Gown & mask
Local Anesthetic(1%Xylocain Injection)
One part needle
Sheath(6Fr).
Syringes , needle , suture material , scalpel.
Sterile gauze.
Transparent dressing.
27. Assembling pacemaker……cont’d
Connector pins on the lead(s) must be fully inserted in the
patient connector block
Black to negative & red to positive
Finger tighten only (no tools required)
28. Procedure explained
IV Aceess
Placement of sheath
Pacing lead insertion
* Desirable location for pacing RV is usually the apex
* Catheter should pass tricuspid valve to reach RV
Connect to pacemaker.
* (Rate , sensitivity , output setting)
Securing of the lead to skin.
Apply transparent dressing.
29. Determining OUTPUT THRESHOLD
Gradually turn down output until ventricular capture is
lost
The last point before losing capture is the threshold
Pacemaker output should be set as 3-4 times the
threshold
(ie if the threshold is 2 ; set output at 6)
31. ECG - Look for Pacing spikes (stimulus from the pacemaker ,
which is recorded in ECG as short narrow deflection)
32. Ongoing management
Daily inspection of the site for signs of infection
Threshold checking
Daily ECG
Low battery indicator
Connections are secure
Setting ( rate, output, sensitivity )
Setting ( demand or asynchronous )
Pulse perfusion distal to insertion site
Presence of Muscle twitching or hiccup
34. Complication………cont’d
Loss of capturing ; Causes can be related to
1)Patient’s condition (Hypoxia , acidosis , electrolyte
imbalances leads to increased threshold)
2)Lead position(catheter dislodgement , poor endocardial
contact ,perforation etc)
3)Generator malfunction
4)Battery depletion
CAPTURED BEAT NON CAPTURED BEAT
35. BATTERY
Use a fresh battery with each patient
9 V alkaline battery
or
9 V lithium battery
Monitor battery status Low battery LED blinks red
and the device will beep when battery is getting low
36. Low battery warning
The Low Batt/Error LED will flash red (every 5 s) and device will beep
(every 5 min) .
Replace battery when possible .
If device turned off after the low battery warning begins, the battery
must be replaced before the device can be turned on again .
37. Replacing the battery
Replacing the Battery
• Do not replace battery while connected to patient
• Slide the compartment lid (12) to the side
• Remove the battery from the compartment and
disconnect from the battery clip
• Connect new battery with correct polarity to the battery
clip
* DOES NOT PROVIDE PACING WHEN BATTERY IS
REMOVED
38. Atrial high rate pacing
Overdrive suppression of tachyarryhthmia
Ensure leads/wires in atrium •Set Basic Rate: 30-180 ppm
Set Mode: x2 or x4
Press and hold High Rate to deliver RAP
x2 = Basic Rate x2 Range = 60 - 360 ppm
x4 = Basic Rate x4 Range = 120 - 720 ppm
Release High Rate button to stop
