Dr. James McCord of the Henry Ford Medical System in Detroit said two standard heart attack treatments -- clot-busting drugs and beta-blockers -- can be dangerous if someone has been using cocaine.

Most cocaine-associated chest pain is not a heart attack, therefore it is recommended that these patients be monitored in an observation unit for nine to 12 hours, McCord said.

Studies indicate chest pain related to cocaine tends to show up within three hours of using the drug, but the chemical can remain in the system for at least 18 hours and can continue to cause problems, McCord explained.

Cocaine increases the heart's need for oxygen by driving up heart rate, elevating blood pressure and increasing the heart's contraction with each beat. At the same time, cocaine deprives the heart of oxygen by constricting the blood vessels and making the blood more likely to clot and cause a heart attack.

The recommendation in a new American Heart Association scientific statement published in Circulation: Journal of the American Heart Association.