When a heart attack occurs, delaying treatment by even a few minutes could be deadly.

But many people wait hours after symptoms set in to get care — either because they feel mentally “frozen” and unable to act, or because they’re slow to recognize the seriousness of the situation, a new survey reveals.

The finding stems from a look at how 300 Swedish patients reacted while having a heart attack.

“The patients who waited more than 12 hours seeking medical care when having symptoms perceived an inability to act,” said study lead author Carolin Nymark. These patients often described feeling as if they had “lost control over themselves.” Others said they felt unable to take any action because they didn’t know how to react or what to do.

Nymark works in the department of neurobiology at Karolinska University Hospital in Stockholm. She and her colleagues reported their findings online May 27 in the European Journal of Cardiovascular Nursing.

The researchers said that heart attack symptoms can show up as several forms of moderate-to-severe discomfort, including chest pain, or pain affecting the throat, neck, back, stomach and/or shoulders for 15 minutes or more. Nausea, cold sweat, weakness and shortness of breath may also set in, along with a sense of foreboding, fear or powerlessness.

“Another red flag is feeling you have no power to act on your symptoms,” Nymark said. “This may indicate a real health threat and the need to call an ambulance.”

The survey was conducted between 2011 and 2014, while respondents were hospitalized after a first or second heart attack.

Patients waited a median of about three hours after their first symptoms to seek care. Half reacted sooner, half took longer — some as much as 24 hours or more.

Seeking care in less than an hour was considered a “very short delay” response. Those who waited 12 hours or more were included in a “very extended delay” group.

The researchers wanted to assess the behaviors that might affect choices one makes with respect to seeking medical care, as well as the thoughts and actions of patients during a heart attack.

Patients were asked how seriously they viewed their symptoms, how urgently they sought medical care, and whether they felt plagued by an inability to take action.

Those who reacted quickly knew their symptoms were serious and where they should go to get help. And they didn’t try to put the symptoms out of mind, the study found.

But many who delayed treatment said they hadn’t understood their symptoms, underestimated their seriousness or thought they would pass. Some said they thought getting care would be difficult. They also reported being gripped by an overriding feeling that they were out of control and were powerless to respond.

As to whether that kind of “freezing up” in the face of a heart attack might arise from denial, fear, hopelessness and/or disbelief, Nymark said: “It’s probably a mixture of these things, but we haven’t investigated it, so we can’t say.”

Looking ahead, however, she suggested that hospital and cardiac rehabilitation caregivers might want to broach the issue with heart attack survivors so they will be better prepared if and when a second attack occurs.

Dr. Gregg Fonarow, director of the Ahmanson-UCLA Cardiomyopathy Center at the University of California, Los Angeles, reviewed the study findings. He noted that campaigns urging people to react quickly to signs of a heart attack have fallen short.

“Despite decades of educational campaigns and other efforts, there are still many men and women who delay seeking medical attention after the onset of symptoms,” he said. “These findings may help guide future interventions to help individuals seek care for acute cardiovascular conditions sooner rather than later.”

One tactic would be to offer patients guidance on coping with difficult decision-making situations, Fonarow said. Another would be to better educate the general public, so people are better prepared to spot, interpret and react to heart attack symptoms.

More information

To learn more on key signs of a heart attack, visit the American Heart Association.