
As if Monday wasn’t bad enough: the weekend is over, and for many of us, it’s back to work. Now, the most life-threatening heart attacks are more likely to occur on Mondays than any other day of the week, according to research presented at this year’s British Cardiovascular Society meeting.
ST-segment elevation myocardial infarction, or STEMI for short, occurs when a large artery supplying blood to the heart muscle becomes completely blocked by a plaque or clot. The blockage can lead to the death of the heart muscle, which means the heart cannot pump blood efficiently throughout the body.
STEMI gets its name from the ST-segment elevation seen on an electrocardiogram (ECG), which indicates that the conduction of electrical impulses through the heart, particularly in the lower chambers (the ventricles), has changed. STEMI is more serious and carries a greater risk of serious complications and death than non-STEMI heart attacks.

Researchers from Belfast Health and Social Care Trust and the Royal College of Surgeons of Ireland analyzed data from 10,528 patients admitted to hospital with STEMI in Ireland between 2013 and 2018.
They found that Mondays had the highest STEMI rates, and Sundays also had higher-than-expected STEMI rates. They dubbed this phenomenon “Blue Monday,” but nothing was known about why it happened.
“We found a strong statistical correlation between the start of the work week and the incidence of STEMI,” said Jack Laffan, head of research at the Belfast Health and Social Care Trust. “This has been described before, but remains a curiosity.”
The researchers believe this may have something to do with the body’s circadian rhythms — changes in the body, mind and behavior that follow a 24-hour cycle, the body’s “internal clock.” Circadian rhythms guide sleep and eating patterns, hormones, and body temperature, which is why it’s important to maintain a routine, including on weekends.
“The cause may be multifactorial, but, based on what we know from previous studies, it is reasonable to assume a circadian factor.”
Research results and Review of 2005 28 previous studies covering 16 countries and more than 1.6 million cardiac events. The review suggested that “Blue Monday” may have been linked to drinking, but could not prove it was a contributing factor.
Or it might come down to the stress of returning to work after the weekend. A Study in 2020 Employees were found to be less job-satisfied and more vulnerable to job stress at the start of the workweek. The body’s physiological response to stress is known to increase the risk of high blood pressure, heart disease and stroke.
The researchers said further research is needed to investigate the causes of “Blue Monday”.
“This study adds to the evidence about when heart attacks are particularly severe, but we now need to figure out what makes certain days of the week make heart attacks more likely,” said Nilesh Samani, medical director at the British Heart Foundation. “Doing so can help doctors better understand this deadly disease so we can save more lives in the future.”
The study in 2023 british cardiovascular society meeting in Manchester, UK.
source: British Heart Foundation