For many people with heart disease, drugs alone will not convert an arrhythmia to a normal heart rhythm. For these people, a procedure called cardioversion or electrical cardioversion may be necessary.
Cardioversion is a treatment for heart rhythms that are abnormal (arrhythmia). During cardioversion, a special machine is used to send electrical energy to the heart muscle to restore normal rhythm. The procedure restores the normal heart rate and rhythm, allowing the heart to pump more effectively.
Cardioversion can be used to treat many types of fast and/or irregular heart rhythms. Most often, it is used to treat atrial fibrillation or atrial flutter. But cardioversion may also be used to treat ventricular tachycardia, another arrhythmia that can lead to a dangerous condition called ventricular fibrillation (a cause of sudden cardiac death.)
How Is Cardioversion Performed?
During cardioversion, your heart and blood pressure are monitored and a short-acting sedative is given. Then an electrical shock is delivered to your chest wall through paddles or patches that stops the abnormal heartbeat and allows your heart to resume a normal rhythm.
Your doctor may want to give you blood thinners prior to and for a period after the procedure.
In some people, a moderately invasive imaging test called transesophageal echocardiogram (or TEE) may be performed prior to the cardioversion to make sure that the heart is free from blood clots. The TEE is performed by swallowing a narrow tube with a camera at its tip that can be placed against the back wall of the heart.
Because the patient is sedated, the shock isn't felt or remembered. A successful cardioversion may take several electrical shocks.
What's the Difference Between Cardioversion and Defibrillation?
Cardioversion and defibrillation procedures both use a device to deliver an electrical shock to the heart.
Electrical cardioversion, however, uses much lower electricity levels to give the shock than defibrillation. Defibrillation is often used to treat much more difficult to convert arrhythmias.
What Happens After Cardioversion?
Recovery from cardioversion only takes a few hours.
After the procedure, you may also be required to take antiarrhythmia drugs to help your heart maintain its normal rhythm.
Additional cardioversion procedures may be needed as well.