Why sudden cardiac deaths no longer peak on weekday mornings

Owing to increased stress, deaths from sudden cardiac arrests are more likely to happen on any day at any time, finds a new research, challenging previous claims that weekday mornings -- especially Mondays -- were the danger zones.

Almost 17 million cardiac deaths occur annually worldwide while the survival rate from sudden cardiac arrest is less than one per cent.

"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 Sumeet Chugh, an Indian-origin Professor of medicine from the Smidt Heart Institute in the US. 

"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 added.

For the study, published in the journal Heart Rhythm, the team analysed data on 1,535 patients who died from sudden cardiac arrest, among which only 13.9 per cent died in the early morning hours, the findings revealed.

"Because sudden cardiac arrest is usually fatal, we have to prevent it before it strikes," Chugh said. 

"Our next steps are to conclusively determine the underlying reasons behind this shift, then identify public health implications as a result," he added. 

Apart from stress, other contributing factors may be a shift in how high-risk patients are being treated, as well as inadequacies in how past studies have measured time of death caused by sudden cardiac arrest.