Catheter ablation is a medical procedure that treats some kinds of arrhythmia, or abnormal heartbeats. In this procedure, your doctor will insert one or more catheters into a blood vessel in your groin, arm, or neck and guide them into your heart. A special machine sends energy, usually radiofrequency energy, into the heart tissue to destroy the tissue causing the abnormal heartbeat. Some people go home the same day, and others need more time to recover in the hospital.