Cardioversion

Question 1

What is cardioversion ?

Answer 1

• a medical procedure by which an abnormally fast heart rate (tachycardia) or other cardiac arrhythmia is converted to a normal rhythm using electricity or drugs.

Question 2

What are the 2 different types of cardioversion ?

Answer 2

• synchronized electrical cardioversion

- pharmacologic cardioversion

Question 3

Synchronized electrical cardioversion: what is it

Answer 3

• is the uses a therapeutic dose of electric current to the heart at a specific moment in the cardiac cycle, restoring the activity of the electrical conduction system of the heart.

Question 4

Synchronized electrical cardioversion: procedure

Answer 4

• place 2 electrode pads with saline gel -> one on right parasternal line + one on the left anterior mid-axillary line -> shock with a selected amount of current at R wave of the QRS

Question 5

Synchronized electrical cardioversion: what to do in case of hemodynamically unstable patient

Answer 5

• patient is sedated during the procedure, if he is hemodynamically stable, but
• if patient is hemodynamically unstable -> induce a shock directly after conforming the arrhythmia

Question 6

Synchronized electrical cardioversion: indications, and contraindications

Answer 6

• Indications for supra ventricular tachycardia: A-fib, A-flutter, VT and junctional tachycardia
  Note: Pulseless VT and V-fib are treated with unsynchronized shocks: defibrillation
• Contraindications: synchronized electrical cardioversion is not indicated in sinus tachycardia (differential diagnosis), digoxin toxicity, electrolyte disturbance, fever

Question 7

Synchronized electrical cardioversion: Ongoing things to check

Answer 7

• don’t eat for 6 hours
• thyroid function
• IV access
• sedation
• no one touches the patient

Question 8

Synchronized electrical cardioversion: special situation

Answer 8

• pregnancy (usually with intubation), pacemaker (don’t position the paddles in the same vector)

Question 9

Synchronized electrical cardioversion: complications

Answer 9

• asystole/bradycardia
• V-fib
• thromboembolism
• hypotension
• skin burn
• aspiration pneumonitis

Question 10

Pharmacologic cardioversion: what is it

Answer 10

• also called chemical cardioversion, uses antiarrhythmia medication instead of an electrical shock, goal is to lower the HR back to a normal rhythm

Question 11

Pharmacologic cardioversion: what is used

Answer 11

• mainly anti-arrhythmic agents: amiodarone, cardizem, metoprolol
• Anti-arrhythmic drugs:
  .Class I -> Na channel blockers: Quinidine, lidocaine
  .Class II -> BB
  .Class III -> blocks outward K channel: amiodarone, stall
  .Class IV -> Calcium Channel blocker which inhibits AP in AV and SA node

Question 12

Pharmacologic cardioversion: what is used in stable patients

Answer 12

• adenosine