Cardioversion

From Anvita Health Wiki

Contents 1 More Specific Terms 2 Indications 3 Management 4 Notes 5 More General Terms 6 References

More Specific Terms

• chemical cardioversion
• defibrillation (electrical cardioversion, automated external difibrillation, AED)
• synchronized cardioversion

Indications

• supraventricular tachycardia

• atrial fibrillation, atrial flutter

Management

• see defibrillation for ventricular tachycardia & ventricular fibrillation
• cardioversion for atrial fibrillation/ flutter

• DC cardioversion (50, 100, 200, 300, 360 joules)

• synchronized transthoracic DC cardioversion [2]

• 67-100% efficiency
• ibutilide IV prior to cardioversion decreases energy required for cardioversion
• risks

• anesthetic
• ventricular fibrillation from poor synchronization

• transvenous electrical cardioversion [2]

• useful when transthoracic cardioversion has failed
• usually shock between electrodes in right atrium & coronary sinus & or indifferent electrodes on the back
• low energies often effective

• monophasic defibrillator: 360 J single shock
• DC cardioversion more effective than chemical cardioversion [3]

• chemical cardioversion

• pharmacologic agents

• class 1A, 1C or 3 antiarrhythmic agents

• conversion & maintenance of sinus rhythm

• indications

• patient is unstable
• mitral stenosis
• mitral regurgitation
• new onset of atrial fibrillation within 48 hours

• anticoagulation for patients with long-term AF*

• 3 weeks prior to elective cardioversion
• 4 weeks after successful cardioversion

• antiarrhythmic therapy for maintenance of sinus rhythm

• may or may not be needed
• amiodarone (most commonly used)

• 400 mg for 30 days, then 200 mg QD
• especially useful with structural heart disease

• if no structural heart disease

• flecainide 100 mg BID, or
• propafenone 150-225 mg TID

• 30-50% of patients will maintain sinus rhythm after 1-2 years

Notes

• since atrial fibrillation usually involves the left atrium, elective attempts at chemical or electrical cardioversion should be preceded by anticoagulation therapy of at least 3 weeks duration to minimize the risk of systemic embolization upon restoration of sinus rhythm
• alternatively, atrial thrombi may be excluded by transesophageal echocardiogram
• following conversion to sinus rhythm, type Ia antiarrhythmic agents ( quinidine, procainamide) or type III antiarrhythmic agents ( amiodarone, sotalol) can be used in an effort to sustain sinus rhythm
• because atrial contractility may take up to a month to recover ( atrial stunning), it is recommended to continue anticoagulation for 4 weeks after successful cardioversion

More General Terms

• clinical procedure

References

1. Saunders Manual of Medical Practice, Rakel (ed), WB Saunders, Philadelphia, 1996, pg 238-40
2. Feliciano, Z. In: UCLA Intensive Course in Geriatric Medicine & Board Review, Marina Del Ray, CA, Sept 12-15, 2001
3. Bellone A et al. Cardioversion of acute atrial fibrillation in the emergency department: A prospective randomised trial. Emerg Med J 2012 Mar; 29:188. PMID: [1]

cardioversion