Regular day-night cycles ‘can improve recovery after heart attacks’

Recovery for heart attack patients in intensive care units can be aided by maintaining normal day/night cycles, a new study has revealed.

Conducted by the University of Guelph, the research shows for the first time that interrupting diurnal rhythms can impair healing immediately after a heart attack, building on the existing understanding that circadian rhythms can affect the timing of an attack.

Examining rodents held under normal light and dark cycles with others whose diurnal cycles were disrupted for five days after the attacks, it was found that poor adherence to day/night rhythms imparied inflammatory and immune responses crucial for scar formation and healing.

This is an important discovery given the noise, light, and other interruptions that often disturb acutely ill patients in intensive care.

Professor Tami Martino of the Department of Biomedical Sciences at the University of Guelph said: "We have devised a simple way to better practise medicine to improve the outcome from heart attacks by considering normal circadian rhythms. It has an immediate life application."

The British Heart Foundation estimates that around 50,000 men and 32,000 women have a heart attack every year in England.