Synchronized Cardioversion
Objectives
1. Understand what Synchronized Cardioversion is
2. Detect conditions in which Synchronized Cardioversion is necessary
3. When to Implement appropriate protocols
4. How to perform Synchronized Conversion
What is Cardioversion
Synchronized Cardioversion
- Electrical & Pharmacological
- Electrical Cardioversion is a medical procedure that uses electrical shocks to treat abnormal heart rhythms also known as arrythmias, more specifically tachycardias.
- The procedure is done by delivering a brief current across the chest through a pair of adhesive “hands-free” patches or better known as AED pads.
Synchonized Cardioversion
- Cardioversion depolarizes the bulk of cardiac muscle simultaneously, disrupting the abnormal electrical circuits, allowing the heart’s pacemaker to regain control and restore normal rhythms.
- The delivery of the shock is synchronized to the QRS complex, which represents ventricular depolarization. This timing is critical to prevent the R-on-T phenomenon, which could put the patient into cardiac arrest.
Heart Function
- Contractions of the heart muscle are coordinated by electrical impulses that are initiated in the heart’s natural pacemaker- the SA (Sinoatrial Node) node.
- AV Node
- Bundle of His
- Left and Right Bundle Branch
- Purkinje Fibers
- P wave- Contraction of Atria
- Q wave- Bundle Branch stimulation
- R wave- Left Ventricle contraction
- S wave- Right Ventricle contraction
- T wave- Repolorization of Ventricles
Arrythmias
- Arrythmias occurs when abnormal electrical circuits override the normal conduction of the SA Node.
- Common abnormal rhythms are either initiated from ectopic sites outside the SA node, or caused by an electrical impulse that travels around in a localized self-perpetuating loop called a re-entrant pathway.
Indications and Contraindications
Treatable Rhythms
Indications:
- Tachycardia > 100 bpm
- Unstable Narrow or Wide Complex Tachycardia with a pulse
- Narrow QRS < 0.12 sec (Adult), Narrow QRS <0.09 sec (Pedi)
- Wide QRS > 0.12 sec (Adult), Wide QRS > 0.09sec (Pedi)
Contraindications
- Pulseless Patients
- Stable Narrow or Wide Complex Tachycardias
Narrow Complex Tachycardia
- NCT causing cardiorespiratory compromise (hypotension, AMS, ischemia, chest pain or respiratory distress)
Narrow Complex Tachycardia
Synchronized Cardioversion: Start at 100J, increase until successful conversion.
Consider sedation with Etomidate 0.1 mg/kg IV/IO (max dose 10mg) or Ketamine 0.3 mg/kg IV/IO/IN (max dose 30mg)
Wide Complex Tachycardia
- WCT causing cardiorespiratory compromise (hypotentsion, AMS, ischemia, chest pain or respiratory distress)
Synchonized Cardioversion: Start at 100J, increase until successful conversion
Consider sedation with Etomidate 0.1 mg/kg IV/IO (max dose 10 mg) or Ketamine 0.3 mg/kg IV/IO/IN (max dose
of 30 mg)
Wide Complex Tachycardia
Ventricular Tachycardia with a Pulse
Narrow or Wide Complex Tachycardia
- NCT causing cardiorespiratory compromise (hypotension, AMS, ischemia, chest pain, or respiratory distress)
Synchronized Cardioversion: Start 0.5-1J/kg, increase 2J/kg if unsuccessful
Consider sedation with Etomidate 0.1mg/kg IV/IO (max dose 5 mg) or Ketamine 0.3 mg/kg IV/IO/IN (max dose 15 mg)
Pediatric
Cardioversion Steps
** Prep patient for the procedure
- Place patient on 4-Lead EKG
- Place monitor in "Lead 2" position
- Confirm rhythm by looking at monitor
- Check Pulse
- Apply defibrillation pads using the anterior-posterior approach
- Consider sedation (DO NOT delay if unstable)
- Set monitor to the appropriate energy level for the first cardioversion
- Activate synchronizer
- Charge monitor
- Instruct all personnel to "Clear" and confirm that personnel are clear
- Reconfirm rhythm by looking at the monitor and perform synchronized cardioversion
- Confirm rhythm by looking at the monitor
- Check pulse
- Repeat if needed, based on protocol recommendations
TROUBLESHOOTING
- If you have everything connected but you get this message “Connect Electrodes”
- If you have everything connected and you get this message “Connect Cable.”