Ask the doctor: Should I double up on aspirin if I think I am having a heart attack?

Q. I've heard you should take an aspirin if you think you are having a heart attack. I already take aspirin (325 mg) every day. Should I still take an aspirin if I feel a heart attack coming on?

A. You are absolutely right — it is beneficial to chew on an aspirin tablet if you are having a heart attack. In fact, 911 dispatchers often tell people to do this while they are waiting for the ambulance to arrive.