Published Online: 1 NOV 2012
Copyright © 2013 John Wiley & Sons, Ltd.
Bennett's Cardiac Arrhythmias: Practical Notes on Interpretation and Treatment, Eighth Edition
How to Cite
Bennett, D. H. (2013) Cardioversion, in Bennett's Cardiac Arrhythmias: Practical Notes on Interpretation and Treatment, Eighth Edition, John Wiley & Sons, Ltd, Oxford. doi: 10.1002/9781118432389.ch21
- Published Online: 1 NOV 2012
- Published Print: 14 JAN 2013
Print ISBN: 9780470674932
Online ISBN: 9781118432389
- Delivery of shock;
- Digoxin toxicity;
- Electrical cardioversion;
- Transthoracic cardioversion;
- Transvenous cardioversion
Electrical cardioversion is the delivery of a direct current shock to the heart of brief duration and high energy to terminate a tachyarrhythmia. The usual positions for the defibrillator paddles or self-adhesive electrodes for transthoracic cardioversion are the cardiac apex and to the right of the upper sternum. Except for ventricular fibrillation, shock delivery should be synchronised to the R or S wave of the ECG. Initial energy levels (biphasic) should be 50 J for atrial flutter and 150 J for ventricular fibrillation. 150–200 J is usually required to cardiovert atrial fibrillation. Digoxin toxicity is a contraindication.
In atrial fibrillation or flutter, anticoagulation should precede cardioversion.
Damage to an implanted pacemaker or defibrillator can be prevented if the electrodes are placed at least 15 cm from the generator. Enzyme measurements have shown that cardioversion may affect skeletal but not cardiac muscle. Transvenous cardioversion for atrial fibrillation may be more effective than transthoracic, especially in large patients.