(CNN)The most common time to experience sudden cardiac arrest could be changing, according to new research.
"The dogma -- in fact, this is everywhere, in all the textbooks about sudden cardiac arrest -- [is that] the most common time period for people to have a sudden cardiac arrest is early in the morning," said Dr. Sumeet Chugh, one of the authors of the study published in the journal Heart Rhythm.
Chugh, Price Professor and associate director of the Heart Institute and director of the Heart Rhythm Center at Cedars-Sinai, and his co-authors used the Oregon Sudden Unexpected Death Study to look at 2,631 cases of sudden cardiac arrest.
Of those incidences, the most commonly reported time was the afternoon, when 31.6% of cases happened. Only 13.9% happened in the early morning, 27.6% in the morning and 26.9% in the evening.
The researchers looked at sudden cardiac arrest, an electrical malfunction in the heart, rather than heart attacks, which are blockages, with the understanding that both can happen at the same time.
For Chugh, there were a few ways to explain this change in peak times. Among them is increased accuracy in observations of the timing of the events. Also, treatment is changing for people who experience or could be at risk for sudden cardiac arrest, and medications or other treatments could be affecting their peak times. Another factor may be the shift to a more 24/7 culture.