The risks of electrical cardioversion include the freeing of blood clots in the heart, which may cause a stroke, and the skin at the sites of the electrical paddles may be irritated, explains the American Heart Association. Electrical cardioversion may not restore normal heart rhythms.
The risk of blood clots is greatest when the heart rhythm problem occurs in the left atrium of the heart, according to the American Heart Association. To minimize this danger, patients are often given a medication that decreases the blood's tendency to form clots, such as warfarin. This medication must be taken between two and three weeks prior to electrical cardioversion to be fully effective. If electrical cardioversion fails, a patient needs an implanted pacemaker or an implanted cardioverter defibrillator to maintain normal heart rhythm.
Electrical cardioversion attempts to correct an irregular or rapid heartbeat by briefly stopping the heart with an electric shock, states the American Heart Association. This shock may need to be repeated to be successful. Electrical cardioversion is performed to treat dangerous heart irregularities on an emergency basis and on an elective basis for people with irregular heart rhythms that cause discomfort. Prior to electrical cardioversion, patients are given intravenous sedatives to prevent awareness of the procedure.