To correct atrial fibrillation or reset the heart to its regular rhythm (sinus rhythm), physicians may perform a procedure called cardioversion, using either drugs or electricity.
Cardioversion is not always effective. It may successfully restore regular heart rhythm in more than 95 percent of patients, but more than half of patients eventually go back into arrhythmia. In many instances, anti-arrhythmic medications are needed indefinitely.
What is chemical cardioversion?
Medicines (anti-arrhythmics) are used to stop the heart's quivering and restore normal sinus rhythm. The medications help maintain sinus rhythm for at least 1 year in 50 percent to 65 percent of people. However, they can cause side effects such as nausea and fatigue, as well as some long-term risks. In rare cases, the medications may adversely affect heart rhythm.
What is electrical cardioversion?
While under light anesthesia, a patient receives an electrical shock through paddles or patches on the chest. The shock stops the heart's electrical activity for a split second. When the heart's electrical activity resumes, the rhythm may be normal.
For arrhythmias caused by abnormal heart tissue, catheter radiofrequency ablation (heat) can be used to destroy the abnormal heart tissue.
Catheters (thin, flexible tubes) are threaded through the patient's blood vessels to reach the abnormal heart tissue. The cardiologist then uses a small cutter or radiofrequency energy to remove the abnormal tissue. The procedure does not require open chest surgery.
Implantable Cardioverter Defibrillator
For arrhythmias in which the heart beats too rapidly (tachycardia) or quivers (fibrillates) instead of contracting strongly, an internal cardioverter defibrillator (ICD) can be surgically implanted.
The ICD sends electronic signals to the heart whenever the heart rate reaches a specified limit or goes very high. These signals shock the heart into beating more slowly and pumping more effectively. An ICD is generally not used to treat atrial fibrillation.
How Do Defibrillators Work?
A pacemaker is a device that helps regulate the heartbeat. The device, smaller than a matchbox, is placed under the skin near the collarbone. A wire extends from the pacemaker to the heart.
If a pacemaker detects an abnormally slow heart rate (bradycardia) or no heartbeat, it emits electrical impulses that stimulate the heart to speed up or resume beating.
A pacemaker is often implanted if medications to prevent arrhythmia or control the heart rate result in an excessively slow rate, and following AV node ablation.
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