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Chapter 2
•
Cardiovascular Care
53
HANDS ON
SURGICAL AND OTHER
PROCEDURES
Cardiac Pacing
Cardiac pacemakers are utilized
when there is interruption of the
electrical conduction necessitating
restoration of heart rate. Pacemakers
are effective in the treatment of a
variety of bradycardic and tachycardia
arrhythmias. Utilization of cardiac
pacemakers can restore circulation
and hemodynamics which are
compromised by a slow heart rate.
Temporary Pacing
Temporary pacemakers are utilized
in emergency situations. Temporary
pacemakers contain external, battery-
powered pulse generators, a lead,
or electrode system which can be
transcutaneous or transvenous.
Temporary cardiac pacing
can be
performed in a variety of ways:
•
Internally using transvenous
endocardial leads
•
Externally via transthoracic patches
•
Internally using atrial or
ventricular epicardial leads placed
at the time of surgery
•
Internally via an esophageal
electrode, which is primarily used
for atrial pacing and recording
Transvenous
cardiac pacing is the
preferred method to of pacing
for patients with symptomatic
bradycardias. Transvenous pacing
requires expertise in both venous
and cardiac anatomy in order to
effectively access the vasculature
and advance the electrode into the
heart.
Transvenous Pulse Generator
Output control
determines the
number of
milliamps of
electricity sent
to the heart.
Sense meter
registers every
time the patient’s
heart beats.
Pace meter
registers
every pacing stimulus
delivered to the
heart.
Rate control
sets
the minimum heart
rate at which point
the pacemaker
takes over.
Sensitivity control
adjusts pacemaker
sensitivity to the
patient’s heart rate.
When the dial is set
on
ASYNC
the
pacemaker delivers a
set rate regardless of
the patient’s intrinsic
rate.
Connector
attaches
the pacing wires to
the pulse generator.
Battery
compartment
Left
subclavian
vein access
site for
pacing wire
Transvenous
pacing wire
in right
ventricle
Connector
Pulse
generator
Transcutaneous Electrode Placement
For a noninvasive temporary pacemaker, the two pacing
electrodes are placed at heart level on the patient’s chest and
back, as shown. This type of pacemaker can be quickly applied
in an emergency but is uncomfortable for the patient.
Monitoring
electrode
Posterior pacing
electrode
Anterior pacing
electrode
Monitoring
electrode
Pacer wires to pulse
generator
(defibrillator)