NEW YORK (Reuters Health) - Cardiac arrest is a serious consequence faced by crack cocaine users, who tend to be younger and are more likely to survive than cardiac arrest patients who don't use the drug.

In the American Journal of Cardiology, Dr. Priscilla Y. Hsue, of San Francisco General Hospital, and her team describe the first series of patients with cardiac arrest due to cocaine use. Previously, only isolated cases of cocaine-associated cardiac arrest have been described in the medical literature.

The researchers compared 22 patients (average age of 40 years), who reported smoking crack cocaine within 24 hours of the event, with 20 randomly selected cardiac arrest patients (average age of 68 years) with no history of cocaine use. Another 41 cardiac arrest patients who did not use cocaine were matched up to the cocaine users according to age.

Twelve cocaine users experienced a complete neurological recovery, compared with three of the older patients and seven of the younger patients. Cardiac arrest was fatal for 10 cocaine users, while 15 of the older patients and 32 of the younger patients died.

The cocaine users likely fared better because their cardiac arrests were due to drug use, not underlying health conditions, Hsue explained.

"Physicians should consider cocaine use in young people who come into the hospital with cardiac arrest," study leader Hsue told Reuters Health.

Cardiac arrest occurs when the heart stops beating, or when it shifts into an abnormal, unsustainable rhythm, such as ventricular fibrillation, she explained. Cocaine stimulates the part of the nervous system responsible for speeding up the heart rate, she added, and can also throw off the electrical balance within the heart muscle. The drug may also cause structural abnormalities in the heart that predispose a person to developing arrhythmia.

"Although the short-term survival of cocaine users after arrest was better than that of non-cocaine users, we were not able to follow up patients prospectively and do not know their long-term prognosis," the investigators point out in their report.

Cardiac arrest can strike long-time users of the drug, but first-time cocaine users are also at risk, Hsue added.