Rob,
A Rapid heartbeat is a very common symptom of panic attacks, but it is not the only symptom. Feeling lightheaded and anxious are also symptoms. Other common symptoms include: sweating, shaking, difficulty breathing, feeling of choking, chest pain and GI discomfort. People also often have a fear of dying, losing control or going crazy. The symptoms tend to come on rapidly and peak within 10 minutes.
Dr. Tarlow