Download Step by step guide for Synchronised DC Cardioversion

By: Martin Grant
Student no. 40077467
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Cardioversion is defined as a “synchronised
direct current (DC) discharge, and … does not
apply to ventricular defibrillation or to the
pharmacologic reversion of arrhythmias.”
It is synchronised to give electrical discharge
at the point of the Q or R wave in the ECG
cycle.
The reason to synchronise this is to prevent a
shock occurring during repolarisation of
ventricles in the T wave, which can lead to
Ventricular Fibrillation.
Left shows the
various waves
throughout the ECG
and explains what
each deflection
means from the
isoelectric line.
Fig
1
Right shows another
ECG but with colour
demonstrates the
duration of each
different segment.
Fig
2
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Based on advanced cardiac life support (ACLS)
guidelines, any patient with narrow or wide
QRS complex tachycardia (ventricular rate
>150) who is unstable (for example, chest
pain, pulmonary oedema, lightheaded,
hypotension) should be immediately treated
with synchronized electrical cardioversion.
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Supraventricular tachycardia due to re-entry
Atrial fibrillation
Atrial flutter
Atrial tachycardia
Monomorphic VT with pulses
Contraindications
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Digoxin toxicity–associated tachycardia
Sinus tachycardia caused by various clinical
conditions
Multifocal atrial tachycardia
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Midaxillary line
• Right Sternal edge
• Intercostal
spaces
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First of all, the appropriate equipment must
be organised:
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IV access
Airway management equipment
Sedative drugs (midazolam and fentanyl)
Cardioversion monitoring device
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Place patient onto bed
Remove upper garments
Apply heart tracing leads
Conduction strips
Points of
application
Leads: Red, Amber,
Green (Traffic
lights)
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Turn the Cardioversion machine on
Off
Twist green nozzle
clockwise to
activate
Anterolateral pad positioning
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Place on the pads
First pad:
2nd or 3rd
intercostal
space, Right
Sternal edge
Pads and connection
for machine
Second pad: 4th or 5th
Intercostal space ,
Midaxillary line
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Check heart tracing is being picked up
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Press Sync to locate R waves
R waves
indicated
by arrows
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Set the voltage as per guidelines on the
condition presenting with the patient
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WARN EVERYBODY AROUND THE BED YOU
ARE ABOUT TO PRESS CHARGE AND SHOCK
Everyone should step back from the patient
and the bed
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Press Charge
Then Shock
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Watch the monitor and see if the Rhythm has
returned to normal
If not, this may need to be repeated
Below is a before and after ECG from a patient in
AAH with Supraventricular tachycardia resolved
using Synchronised DC Cardioversion
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Synchronised cardioversion when practiced
correctly can be a very effective way to
correct tachycardia’s.
ACLS guidelines should be followed for when
it should be used and at which voltage.
Always check for the contraindications prior
to the procedure.
Follow the steps above for the correct way to
perform the procedure safely and effectively.
1.
2.
Lown B. Defibrillation and
cardioversion. Cardiovasc Res. Aug 1
2002;55(2):220-4.
[Guideline] Part 5: Electrical Therapies.
Automated External Defibrillators, Defibrillation,
Cardioversion, and Pacing. Circulation.
2005;112:IV-35-IV-46.
Figures
1.
http://hyperphysics.phyastr.gsu.edu/hbase/biology/imgbio/ecg.gif