FRIDAY, Oct. 5, 2018 (HealthDay News) — Weekday mornings are no longer the most common time for cardiac arrest, as an ever stressful world means hearts are stopping suddenly at all times of the day, new research shows.

“While there are likely several reasons to explain why more cardiac arrests happen outside of previously identified peak times, stress is likely a major factor,” said lead investigator Dr. Sumeet Chugh. He is associate director of the Smidt Heart Institute at Cedars-Sinai Medical Center in Los Angeles.

“We now live in a fast-paced, ‘always-on’ era that causes increased psycho-social stress and, possibly, an increase in the likelihood of sudden cardiac arrest,” Chugh said in a Cedars-Sinai news release.

For the study, Chugh’s team analyzed data on cardiac arrests in Oregon between 2004 and 2014. Of the 1,535 people who died from sudden cardiac arrest, only 14 percent died between the hours of 6 a.m. and 10 a.m., and there was no evidence that more cardiac arrests occurred on Mondays.

Along with stress, other factors that may explain the findings include changes in how high-risk patients are being treated, and problems with how past studies have measured time of death caused by cardiac arrest, such as using time of death on a death certificate rather than the actual time of death due to cardiac arrest, the researchers added.

Cardiac arrest is different than a heart attack, which is typically caused by reduced blood flow to the heart due to clogged arteries. Cardiac arrest is caused by defective electrical activity of the heart. Patients may have little or no warning, and usually experience sudden death. Each year in the United States, there are about 300,000 deaths from sudden cardiac arrest.

“Because sudden cardiac arrest is usually fatal, we have to prevent it before it strikes,” Chugh said. “This is just another piece to the puzzle. Our next steps are to conclusively determine the underlying reasons behind this shift, then identify public health implications as a result.”

The study was published recently in the journal Heart Rhythm.

More information

The American Heart Association has more on cardiac arrest.