Watching A Stressful Film Can Change Your Heartbeat, Endangering Weak Hearts

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Watching an adrenaline-packed movie packs all the thrills of being exposed to amazing stunts without facing any of the danger.

But now, a new study from the University College London and Guy's and St. Thomas' Hospital, reports the BBC, shows that watching a stressful film does have a detrimental effect if you already have a weak heart.

The changes were not likely to put healthy people at risk, but could be dangerous in those with weakened hearts, researchers said.

Nineteen patients were monitored while watching a clip of Vertical Limit, the harrowing film about two mountain climbers. They found that their heartbeat changed and their blood pressure went up.

"It was the first time the biological effects of mental and emotional stress had been recorded in healthy conscious patients," said the BBC quoting the research team.

“This is the first time that the effects have been directly measured and although the results varied from person to person we consistently saw changes in the cardiac muscle. If someone already has a weakened heart, or if they experience a much more extreme stress, the effect could be much more destabilising and dangerous.”

Film clips were used, the research team said, because they were the ideal stimulus. Electrodes were placed in the ventricles of the heart to measure the changes in cardiac muscle, whilst the team simultaneously recorded changes to blood pressure and breathing speed.

Their respiration rate was also found to increase during the most stressful part of the film clip by two breaths per minute.

The report was published in the journal Circulation, Arrhythmia and Electrophysiology.