Unstable Tachycardia
Hany EL-Zahaby, MD,
Anesthesiologist
Objectives
By the end of this talk we should be able to
describe or demonstrate:
1- 1ry and 2ry ABCD surveys
2- Identify unstable from stable tachycardia
3- Identify the rhythm of tachycardia
4- Determine if tachycardia is producing
hemodynamic instability or the instability is
producing tachycardia
Objectives (cont.)
5- Follow the algorithms for tachycardia
and cardioversion
6- Operation of a defibrillator/monitor to
perform both defibrillation and
synchronized cardioversion
7- Provide post-cardioversion care
Case Scenario
52-year-old man presented to ED
complaining of shortness of breath,
palpitations, dizziness and severe chest
pain. He is pale and sweaty. His Pulse
rate is 178 and blood pressure is 81/50
Action
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Check responsiveness and apply
primary and secondary ABCD surveys
If not in cardiac arrest or VF and
tachycardia is observed, order oxygenIV-monitor-fluids
Identify the rhythm
Supraventricular Tachycardia
Atrial Flutter
Atrial Fibrillation
Atrial Fibrillation
Ventricular Tachycardia

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Prepare for synchronized cardioversion
Prepare oxygen saturation monitor,
suction device, IV line, intubation
equipment, call the code team and
explain to the patient if awake
Premedicate
Sedatives and anesthetics:
 Midazolam (0.01-0.05mg/kg),
 Diazepam (0.05-0.1mg/kg),
 Ketamine(1-2 mg/kg),
 Etomidate (0.2-0.5 mg/kg),
 Thiopentone (3-5 mg/kg),
 Propofol (1-2 mg/kg)

Analgesics:
Fentanyl (1-3μg/kg)
Morphine (0.05-0.1 mg/kg)
Pethidine (0.5-1 mg/kg)
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Synchronized Cardioversion

Is it equal to defibrillation?
Why synchronization?

When not to use synchronization?
Severely unstable VT
Steps for synchronized
cardioversion
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Turn on defibrillator
Attach monitor leads to the patient
Ensure proper display of the patient’s
rhythm (lead II)
Press ‘sync’ control button
Look for markers on R waves
If no markers, adjust monitor gain until
markers on each R

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Select appropriate energy level for type
of arrhythmia
Apply gel to paddles and position it on
patient (sternum and apex)
Announce to team-members “Charging
defibrillators-stand clear”
Press charge button on apex paddle
(right hand)

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When the defibrillator is charged state
firmly: “I am going to shock on three.
One, I am clear. Two, you are clear.
Three, everybody is clear”
Apply 25 Ib pressure on both paddles
Press the “discharge” buttons
simultaneously
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Check the monitor, if tachycardia
persists, increase the joules according
to the algorithm
Reset to “sync” mode after each
synchronized cardioversion
If VF occurs, switch to “defibrillation”
mode and follow the VF/Pulseless VT
algorithm
Energy levels:
 Standard sequence is 100 J→ 200 J →
300 J → 360 J
 Exceptions:
Atrial flutter 50 J→ 100 J→ 200 J→
300 J→ 360 J
Polymorphic VT 200 J→ 300 J →
360 J
Post-conversion care:
 Closely monitor vital signs
 Continue oxygen-IV-monitor-fluids
 Search for a cause for this tachycardia
and treat it
 If VF occurs, recognize need to
defibrillate
 Documentation
Conclusion
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Always start with ABCD
Unstable means either patient or
tachycardia
Unstable tachycardia is treated with
synchronized cardioversion
Steps for cardioversion should be
strictly followed
THANK YOU