Scientists claim taking 30 minute kips each day may raise risk of developing an irregular heartbeat 

Sometimes it’s tempting to have a mid-afternoon siesta to help you get through the day.

But in a warning to snoozers, experts have discovered a 30-minute nap each day may increase the risk of an irregular heartbeat.

Atrial fibrillation is a heart condition that causes an irregular and often abnormally fast heart rate.

It affects more than 40 million people worldwide, and sufferers have a five times greater risk of stroke than their peers.

To find out if napping could be linked to the condition, researchers analysed data on more than 20,000 people who did not have an irregular heartbeat.

Participants filled out a questionnaire every two years and were categorised into three groups according to their average daily nap duration – none, less than 30 minutes or 30 minutes and more.

Compared to short daytime nappers, those who snoozed for 30 minutes or more per day had a nearly doubled risk of developing atrial fibrillation.

Meanwhile, compared with short nappers, risk was not elevated in those who avoided napping.

Further analysis revealed the ideal nap time appeared to be between 15 and 30 minutes, as these people had a 56 per cent reduced risk of developing an irregular heartbeat compared to those who snoozed for half an hour or longer.

Dr Diaz-Gutierrez, from the Juan Ramon Jimenez University Hospital in Spain, said: ‘Previous studies have suggested that sleep patterns may play a role in the development of atrial fibrillation, but as far as we know this was the first study to analyse the relationship between daytime napping and risk.

‘Our study indicates that snoozes during the day should be limited to less than 30 minutes, and the results suggest the optimal napping duration is 15 to 30 minutes.’

He said there are numerous potential explanations for the link between napping and heart health.

For example, long daytime naps may disrupt the body’s internal clock leading to shorter night-time sleep, waking up more during the night and reduced physical activity.

Meanwhile short daytime naps may improve our body clock, lower blood pressure levels and reduce stress.

‘People with disturbed night-time sleep should avoid relying on napping to make up the shortfall,’ he added.

Atrial fibrillation, characterised by symptoms such as heart palpitations, dizziness and shortness of breath, affects around 1.4 million people in the UK.

It can affect adults of any age, but is more common in older people and men.

The findings were presented at the European Society of Cardiology Preventive Cardiology Congress.