Q: I have been taking an appetite suppressant for a diet. Recently I have been experiencing what feels like a racing heart rate, and the sensation that my heart is going to come through my chest. I exercise routinely, but these symptoms are limiting my workout even when I do not take the pill. What can I do?

A: Many diet drugs contain amphetamines and drugs that have an extended half-life (I.e.: are still in the blood stream days after taking the medication). These drugs can cause an erratic or rapid heart rate. If you stop the pills for an extended period of time (5-7 days) and still have the symptoms you should be tested for Cardiac arrhythmias. You may be given a Holter monitor which is a 24-hour EKG that runs a continuous strip of your heart rate or an EKG with a rhythm strip to determine if you have any underlying arrhythmias.