Everyone knows that if you think you're having a heart attack, you should call 911.

But what if you're not sure?

More than half of those having heart attacks die because they don't recognize the symptoms, or because they put off calling 911 until it's too late. Now the University of Minnesota Medical Center is promoting a different approach: a chest pain hot line answered 24/7 by a nurse whose charge is to help patients sort through the symptoms.

They maintain it's not intended as an alternative for 911 -- just a way to reach those who aren't sure what to do.

But other Twin Cities heart experts said the approach could seriously backfire by diluting the hard-won public health message to call 911, and creating potentially dangerous delays in treatment.

Some say the hot line, which is being promoted via radio ads, billboards and direct mail, is nothing more than a marketing tool to recruit patients to the university's heart clinic.

Doctors and nurses who launched the hot line on July 1 said that they do refer callers to their clinic and the university's emergency room. But they aren't urging people to call it instead of 911.

The hot line's targets are people confused about symptoms who may or may not be having a heart attack, said Dr. Gladwin Das, director of interventional cardiology at the University of Minnesota's heart clinic.

"Our slogan is minutes matter," he said. "And delays are deadly."

On that, all cardiologists agree. Each year more than a million Americans suffer heart attacks when their cardiac arteries become blocked by blood clots. If the clot is cleared within an hour after symptoms begin, the damage to heart muscle is minimal, and patients can make complete recoveries. Cardiologists sometimes refer to that window of opportunity as "the golden hour."

That's why most emergency ambulances in the Twin Cities now carry equipment that can immediately diagnose whether a heart attack is occurring, and the emergency medical technicians are trained to provide immediate treatment. They also radio ahead to hospitals so patients can be whisked to a catheterization lab where blocked arteries are cleared.

All of that has made Minnesota a national leader in emergency care systems that have greatly reduced the average time it takes to get heart attack patients to treatment.

"Every time we see a patient that was delayed we always agonize a little bit," said Das. That's what inspired the hot line, he said.

The four nurses answering the line are trained in cardiac care and work for the university hospital's heart clinic. The 800 number rings on a cell phone that they carry when they are on call.

Since the university's Chest-Pain Center advertising campaign began a few weeks ago, it's been ringing a lot, said Kelly Schechter, one of the nurses. Many calls are from people who want to talk about their likely risk for heart disease. But those calling because of chest pain are usually the ones "who would not have sought out medical attention" if they hadn't known about the hot line, she said.

One woman who called this week said she had been seen by a doctor for chronic heartburn, which can sometimes have the same symptoms as a heart attack. But she worried when the pain became more frequent, and was radiating to her shoulder and arm -- a classic heart attack symptom. The nurse on duty told her to call 911, and she came into the university's emergency room. Shechter said she did not know the outcome of her case.

Of the people who show up at emergency rooms complaining of chest pain, one in 10 will be having a heart attack, said Dr. David Cooke, president of the American Heart Association's Midwest affiliate and a Chicago-area cardiologist.

"But it's very hard to diagnose over the phone" he said. The American Heart Association advocates calling 911, he said, because it's been proven to work. Other experts agreed.

"We do see a lot of people in the ER, and it turns out not to be a heart attack," said Dr. Charles Lick, medical director of Allina Hospitals and Clinics' ambulance service. "But if you are having the big one you want to figure it out right away."

Several cardiologists said even well-trained nurses can make mistakes and give people wrong advice.

"Chest pain is not something you triage over the phone," said Dr. Kevin Graham, an Abbott Northwestern cardiologist. "You triage them to the ER."

Still, some experts said the hot line is intriguing. It's clearly a "competitive strategy" to recruit patients, said Dr. Keith Lurie, director of the cardiac resuscitation clinic at St. Cloud Hospital. Many people are frustrated with trying to get immediate guidance from their clinics, and the 911 system can be slow and unwieldy.

"If someone is actually conscious enough to make a phone call, they may get an answer faster than they would by calling 911 and waiting for someone to show up at their door," he said.

Josephine Marcotty • 612 673 7394