Pacemaker

A pacemaker is a small device that's placed under the skin in your chest to help control your heartbeat. It's used to help your heart beat more regularly if you have an irregular heartbeat (arrhythmia), particularly a slow one. Implanting a pacemaker in your chest requires a surgical procedure.

1. Pacemakers

2. Pacemakers
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

3. Types of Pacemaker
Temporary pacemaker
Permanent pacemaker

4. Temporary Pacemaker
Temporary Pacemakers can be used
temporarily , either supportively or
prophylactically, until the condition
responsible for the rate or
conduction disturbance resolves .

5. Indications
Bradycardia
•Heart blocks
•Sinus bradycardia
Tachydysrhythmias
•Supraventricular
Support cardiac output after cardiac surgery
Diagnostic studies
•Electrophysiological studies
•Atrialelectrogram

6. The Pacemaker System
A simple electrical circuit consisting of
PULSE GENERATOR
PACING LEAD

7. Pulse Generator

8. Pacing 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

9. Pacing Lead System
The pacing lead used for temporary
pacing may be bipolar or unipolar
Bipolar Pacing System
In bipolar pacing system, two
electrodes (positive and negative) are
located within the heart

10. Bipolar Pacing System
The bipolar lead used in the
transvenous pacing as two electrodes
on one catheter.
The distal , or negative , electrode is
at the tip of the pacing lead and is in
the direct contact with the heart,
usually inside the right atrium or
ventricle.

11. Bipolar pacing system
Approximately 1 cm from the
negative electrode is a positive
electrode .
The negative electrode is attached to
the negative terminal, and the
positive electrode is attached to the
positive terminal of the pulse
generator, either directly or via a
bridging cable

12. Bipolar pacing system
An epicardial lead system is often used for
temporary pacing after cardiac surgery
The bipolar epicardial lead system has two
separate insulated wires (one negative and
one positive) that are loosely secured with
sutures to the cardiac chambers to be
paced. Both electrodes are in contact with
myocardial tissues, so either wire may be
use as the negative, or ground electrode

13. Bipolar Lead

14. Unipolar Pacing System
A unipolar pacing system has only
one electrode (the negative
electrode) making contact with the
heart.
In the case of unipolar epicardial lead
system, the positive can be formed
by a piece of surgical steel wire sewn
into the sucutaneous tissue of the
chest

15. Unipolar Lead

16. Pacing Routes
Transcutaneous pacing
Transthoracic pacing
Epicardial pacing
Transvenous pacing

17. Transvenous pacing
It involves threading an electrode
catheter through a vein into the right
atrium or right ventricle. Five
different veins can be used.
Antecubital approach
Femoral approach
Subclavian
Internal jugular
External jugular

18. Pacemaker Settings
RATE
OUTPUT
SENSITIVITY

19. RATE
It regulates the number of impulse that
can be delivered to the heart per minute.
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.

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

21. 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

22. ADVERSE EFFECTS
Muscle stimulation
Pneumothorax
Ectopic beats like PVC’s
Ventricular perforation
Perforation of other organs like
Liver
Stomach
Diaphragm

23. Medical Management
The physician determines the pacing
route based on the patient’s clinical
situation. Generally transcutaneous
pacing is used in emergent situations
until a transvenous lead can be
secured.

24. Medical Management
If the patient is undergoing heart
surgery, epicardial leads may be
electively placed at the end of the
operation. The physician places the
transvenous or epicardial pacing
lead(s), repositioning as needed to
obtain adequate pacing and sensing
thresholds.

25. Nursing Management
Four primary areas:
Assessment and prevention of
pacemaker malfunction,
Protection against micro shock,
Surveillance for complications
such as infection
Patient education.

26. Prevention of Pacemaker
Malfunction
The nurse inspects for:
loose connections between the lead(s) and
pulse generator on a regular basis.
Replacement batteries and pulse generator
must always be available on the unit.
The battery has an anticipated lifespan of
1 month, it probably is sound practice to
change the battery if the pacemaker has
been operating continually for several
days.

27. Prevention of Pacemaker
Malfunction
Pulse generators (new generation)
provide a low-battery signal 24 hours
before complete loss of battery
function to prevent inadvertent
interruptions in pacing. The pulse
generator must always be labeled
with the date that the battery was
replaced.