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Home > Patients & Visitors > Health Library > Electrical Cardioversion (Defibrillation) for a Fast Heart Rate
cardioversion is a procedure in which a brief electric shock is given to the
heart to reset the heart rhythm back to its normal, regular pattern (normal sinus rhythm). The shock is given through paddles or patches
applied to the outside of the chest wall.
Usually, the person is sedated. If
the person is conscious, medicine is given to control pain and to cause the
person to relax to the point of being nearly unconscious during the
After cardioversion, the person's heart
rate and blood pressure are monitored.
Additional drugs to help
prevent heart rhythm problems from recurring (antiarrhythmic drugs) may also be
given before and after the procedure. If antiarrhythmic drugs are not used
after cardioversion, the heart may be at greater risk of going back into a fast
After cardioversion, you may take a blood thinner, such as warfarin, for a few weeks to prevent dangerous blood clots.
Cardioversion is often used as an emergency procedure to stop a fast heart rate that is causing low blood pressure or severe symptoms. These heart rate problems include supraventricular tachycardia and ventricular tachycardia.
Also, it is used in nonurgent
situations to convert atrial fibrillation or atrial flutter to normal heart rhythm.
Electrical cardioversion of the heart
is very effective. Most people who receive cardioversion return to normal sinus
rhythm immediately after the procedure.footnote 1
Risks of the procedure include the
Cardioversion is only a temporary
fix for a fast heart rate. Medicines (such as beta-blockers and calcium channel
blockers or other antiarrhythmic medicines) may be used to keep the heart rate
slow when a person has an episode of supraventricular tachycardia (SVT). For
long-term treatment and to reduce the chance of having another episode of
either SVT or ventricular tachycardia (VT), catheter ablation or medicine can
Complete the special treatment information form (PDF)(What is a PDF document?) to help you understand this treatment.
Blomström-Lunqvist C, et al. (2003). ACC/AHA/ESC
guidelines for the management of patients with supraventricular
arrhythmias—Executive summary: A report of the ACC/AHA/ESC Committee for
Practice Guidelines. Circulation, 108(15):
ByHealthwise StaffPrimary Medical ReviewerRakesh K. Pai, MD, FACC - Cardiology, ElectrophysiologySpecialist Medical ReviewerJohn M. Miller, MD, FACC - Cardiology, Electrophysiology
Current as ofFebruary 20, 2015
Current as of:
February 20, 2015
Rakesh K. Pai, MD, FACC - Cardiology, Electrophysiology & John M. Miller, MD, FACC - Cardiology, Electrophysiology
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