Electrical Therapies( Automated Electrical Defibrillators,Defibrillation, Cardioversion, Pacing)
Immediate CPR until defibrillator available
1-Shock vs 3-shock sequence
No studies humans/animals comparing the two
Animal studies: long interruptions in CPR assoc w/ post-resuscitation myocardial dysfunction and decrease survival
RCT: interruptions in CPR assoc with decreaseprobability of conversion of VF to another rhythm
3-Shock: 37 sec delay before 1st compression
1-Shock: efficacy of conversion more than 90% (biphasic defibrillators)

Monophasic vs Biphasic Defibrillators
1st-shock efficacy of monophasic less than 1st-shock efficacy of biphasic
Goal: delivery of current through chest to the heart to depolarize myocardial cells and eliminate VF/VT
Monophasic: delivers current of one polarity
1-shock 360J
Biphasic : less than 200J as safe and with higher efficacy than higher voltage in monophasic

Automated Electrical Defibrillators(AED)
Only useful for shockable rhythms
If implantable medical device (pacemaker, AICD) placed, this should place 1 inch away
Do Not place on transdermal medication devices as it causes burns, decrease energy to heart
If Individual wet/diaphoretic make him dry
For decreasing impedance we have to Shave chest hair and apply Conductive gel
Arched placement of AED in O2-rich environment can spark fires

Synchronized Cardioversion
Shock delivery timed with QRS complex
Indicated for Rx of unstable tachyarrhythmias associated with organized QRS complex and a perfusing rhythm
Rx unstable SVT -Reentry,Atrial Fibrillation ,Atrial flutter ,Unstable monomorphic VT
NOT effective in Junctional tachycardia,Ectopic/multifocal-atrial tachycardia (automatic focus)and Shocks to automatic focus can further increase HR


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