Heart attack patients often take longer to seek help if they have gradual symptoms, which may put them at increased risk of death, according to authors of a study published in the European Journal of Cardiovascular Nursing.

Gradual symptoms begin with mild discomfort that slowly worsens, while abrupt symptoms are sudden and cause severe pain.

Study author Sahereh Mirzaei, from the University of Illinois at Chicago, and her team analyzed data from 474 heart attack patients seen at U.S. emergency departments. Symptoms were gradual in 44 percent and abrupt in 56 percent of these patients.

Those with gradual symptoms waited eight hours to seek medical help, compared to 2.6 hours for those with abrupt symptoms. A delay of no more than two hours is recommended for the best outcomes. Waiting longer increases patients’ risk of serious complications and death, according to the researchers.

Symptoms were triggered by exertion, such as running, climbing stairs, or shoveling snow, in 54 percent of men with abrupt onset and a diagnosis of ST-elevation myocardial infarction, which is a particularly serious type of heart attack requiring quick restoration of blood flow to blocked arteries.

Mirzaei said men with ischemic heart disease or multiple risk factors such as high blood pressure, diabetes, high cholesterol, or a family history of heart disease should be aware that chest pain or discomfort after physical activity or exercise could be a heart attack.