The early morning may no longer be the most common time people experience sudden cardiac arrest, according to a study published in Heart Rhythm.
For the study, researchers analyzed data on 1,535 adult patients who experienced a sudden cardiac arrest in the Northwest U.S. between 2002-14. The data came from an ongoing population-based study called "The Oregon Sudden Unexpected Death Study."
Researchers found most patients experienced sudden cardiac arrest in the afternoon (31.6 percent of cases), followed by the morning (27.6 percent), evening (26.9 percent) and early morning (13.9 percent).
"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," study author Sumeet Chugh, MD, medical director of the Heart Rhythm Center at Cedars Sinai Medical Center in Los Angeles, told CNN.
Previous studies have also shown Mondays are the most common day of the week to experience sudden cardiac arrest. However, the researchers did not find such a peak. Instead, they discovered a slight drop in sudden cardiac arrests on Sundays.