The Charles L. Tice Heart Center for Diagnostic Services:
Cardioversion is used by the cardiologist to correct atrial fibrillation and atrial flutter. Atrial fibrillation is when the upper chambers of the heart are beating very fast and erratically. Atrial flutter is similar to atrial fibrillation, but the upper chambers of the heart are beating more rhythmically. Cardioversion is synchronized electrical stimulation of the heart using a defibrillator, which encourages the heart to return to a normal rhythm.