Question: I am experiencing abnormally rapid heartbeat and dizziness when I exercise. I’m a 25-year-old woman. I’ve had an echocardiogram done and everything is normal with my heart. Do you know what could be causing this racing of my heart?

Dr. Hibberd’s answer:

Any person with rapid heartbeat complaints that are not evident on EKG should have an ambulatory EKG or holter monitor test performed in an attempt to identify what is actually happening.

A stress test may be the swiftest and safest way to assess your condition. If it doesn’t turn anything up, consider a holter monitor or an event monitor you can carry and place over your chest wall to record your heartbeat during an episode where it starts racing. The recording can often be transmitted by phone later and reviewed.

Ask your doctor for a referral to a cardiologist if he or she is not comfortable with doing a further evaluation.