Using special skin patch electrodes, applied to the chest, an electroshock is delivered to the heart to stop an abnormal heart rhythm (typically atrial fibrillation) and establish a normal heart rhythm.
Success rate: >90%
These are rare and occur at < 1-2% of patients: Stroke (see comment below) and minor, transient skin burning. There may also be risks related to sedation, and there may be the need to administer more than one shock.
What to expect
This is an outpatient procedure done in the cardiac pre-op area, though patient has to be driven home, and cannot drive for 24 hours. The procedure takes about a half hour.
Patient arrives (no food that morning) to the cardiac pre-op area. Intake paperwork is being completed. ECG electrodes are attached and an intravenous (I.V.) line is placed. The blood pressure, heart rate and blood oxygen values are monitored. Defibrillation patches are placed to the front chest and the middle back area – these are sticky patches (often a bit cold, too) through which the electroshock will later be delivered. Conscious sedation is administered. These medications make the patient very sleepy, but it is not the same as anesthesia. After the patient is fully sedated, the electroshock is delivered (sometimes more than one is necessary) and the resulting heart rhythm is analyzed. The patient does not remember the shock. An ECG is taken to document the return of a normal heart rhythm.
The patient’s recovery from conscious sedation is monitored. Typically the patient is ready to leave after 1-2 hours. We arrange for follow-up ECGs (often done by the referring physician and faxed to us) to review the heart rhythm.
While the electrical cardioversion is very successful in terminating the abnormal rhythm and establishing a normal heart rhythm, it is not effective in maintaining a normal heart rhythm. For this purpose we use medication (anti-arrhythmic drugs).
Proper anticoagulation with coumadin/warfarin is a pre-requisite in order to avoid procedure-related strokes. In some patients, we need to perform a trans-esophageal echocardiogram to exclude the presence of clots inside the heart. You also will be asked to have your INR checked (blood test for the coumadin) up to 48 hours prior to the procedure.