Sudden Cardiac Death,

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• Sudden Cardiac Death,
• Prehospital Amiodarone Administration and
• Defibrillation Waveforms
• Tyler Cascade
• March 2002
• tcascade_at_yahoo.com

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Question Is monophasic or biphasic
defibrillation better, after a 300 mg IV
amiodarone bolus, for the treatment of sudden
cardiac death? Hypothesis 1 Monophasic is
better Hypothesis 2 Biphasic is better Null
Hypotheses The relationship between amiodarone,
defibrillation threshold, and defibrillation
waveforms does not affect survival after sudden
cardiac death.
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Mortality of Sudden Cardiac Death,
USA, 1999.

• Sudden Cardiac Death (SCD) Definition
• unexpected
• cardiac cause
• short period of time from symptom onset to
  cardiac arrest

(Centers for Disease Control)
800,000
728,743
700,000
600,000
462,340
500,000
341,780
400,000
323,638
300,000
200,000
120,244
100,000
0
All Cardiac Disease
SCD Out-of-Hospital
SCD in ED or Dead on Arrival
Sudden Cardiac Deaths (SCD)
SCD Secondary to myocardial infarction
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What can we do to help these folks live longer
lives, with a good quality of life?
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• Early 911 and Dispatcher Assistance
• Early CPR
• Early Defibrillation
• Most Important
• Early Drugs
• Epinephrine, Vasopressin
• Amiodarone, Lidocaine
• Beta-Adrenergic Blockers

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Amiodarone for resuscitation after
out-of-hospital cardiac arrest due to ventricular
fibrillation. Kudenchuk PJ, Cobb LA, Copass MK,
Cummins RO, Doherty AM, Fahrenbruch CE,Hallstrom
AP, Murray WA, Olsufka M, Walsh T. New England
Journal of Medicine. 1999 Sep 16341(12)871-8.
Survival to Hospital Admission (n504) 43
Amiodarone Group 34 Placebo Group Survival
to Discharge 13.4 Amiodarone
Group 13.2 Placebo Group 7 Return to
Independent Living or Prior Employment
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External Internal Defibrillation Waveforms
Currently In Use

• MTE1- Monophasic Truncated Exponential
• MDS2- Monophasic Damped Sine Wave
• BTE3- Biphasic Truncated Exponential
• RBW4-Rectilinear Biphasic Waveform

200, 300, 360 Joules 120, 150 Joules
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• 3rd 4th Generation Waveforms
• Patient Impedance
• Variables include
• Distance between electrodes (chest size)
• Volume of air in the lungs
• Skin properties
• The use of conductive gels
• BTE RBW
• Waveforms
• 50 150 Ohms
• Impedance Compensation
• 120, 150 Joules

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Monophasic Waveforms Impedance
Monophasic Damped Sine Waveform (MDS) Comparison
of Waveform with 50 150 Ohm Impedances 2nd
Generation Figure 8 200, 300, 360 Joules
Monophasic Truncated Exponential (MTE)
Waveform Comparison of Waveform with 50 150
Ohm Impedances 1st Generation Figure 4
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Shortening the second phase duration of biphasic
shocks effects of class III antiarrhythmic drugs
on defibrillation efficacy in humans. Merkely B
Lubinski A Kiss O Horkay F Lewicka-Nowak E
Kempa M  Szabolcs Z Nyikos G Zima E Swiatecka
G Geller L.  Journal of  Cardiovascular
Electrophysiology. 12(7), 824-7 (Jul 2001).
Department of Cardiovascular Surgery, Semmelweis
University, Budapest, Hungary.

• Effects of chronic oral amiodarone on
  defibrillation threshold
• (Internal defibrillation)
• Findings
• DFT Affected by amiodarone
• amiodarone responded differently to different
  waveforms
• Optimal phase II 2.5 ms

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Defibrillation ThresholdMinimum amount of energy
needed to successfully defibrillate the heart
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Research Web Sitehttp//academic.evergreen.edu/c
/casasp04/