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‘Harmless’ heart condition is linked to sudden death syndrome 

A heart condition that affects 1.2 in every 100 people has been linked to sudden death syndrome.

Mitral valve prolapse occurs when the valves that separate the different chambers of the heart do not close properly.

Although generally thought to be harmless, a study by the University of Adelaide found 12 per cent of people who die when their hearts suddenly stop beating have MVP.

A heart condition that affects 1.2 in every 100 people has been linked to sudden death (stock)

MVP occurs when the heart’s mitral valve becomes too floppy and therefore does not close as tightly as it should.

This can affect how blood flows around the body, however, NHS Choices states it often does not require treatment. 

‘Mitral valve prolapse is condition in which the leaflets of the valve (mitral valve) that lets blood flow from one chamber to another does not close smoothly or evenly, instead they bulge upward into the left atrium of the heart,’ lead author Dr Rajiv Mahajan said.

‘Over the years, there have been several case studies associating mitral valve prolapse with unexplained sudden cardiac death, however, the link had not been confirmed.’ 


Mitral valve prolapse (MVP) occurs when the small flap in the heart that stops blood flowing the wrong way becomes too floppy and does not close properly.

Many people with MVP have no symptoms and the condition is only spotted during a heart scan that is carried out for another reason. 

MVP affects around 1.2 in every 100 people.  

In some cases, it can cause:

  • Dizziness
  • Breathlessness
  • Fatigue
  • An irregular heartbeat or palpitations 

Most cases do not require treatment, according to NHS Choices.

Doctors may recommend lifestyle changes such as giving up smoking, alcohol or caffeine due to these causing the heart to become overworked.

In severe cases, medication such as beta-blockers can help treat an irregular heartbeat.

Surgery may also be required to repair or replace the mitral valve.

Most people with MVP were born with the condition.

But it is more common in those with connective tissue disorders, such as Marfan syndrome.

In rare cases, MVP can occur due to damage to the cardio muscles, for instance after a heart attack.

The researchers analysed 34 studies that assessed how common MVP is and how often it leads to sudden cardiac death (SCD).

Results, published in the journal Heart, suggest just 1.2 per cent of people in England suffer from MVP.

But in 11.7 per cent of SCD cases, the deceased was suffering from MVP.

Sudden death syndrome occurs when an otherwise healthy person passes away suddenly, with the cause likely being a heart condition.

In around one in 20 spontaneous heart-related deaths in the UK, no definite cause can be found.

The researchers believe MVP’s high prevalence in SCD suggests it may cause sudden death, particularly as the valve disorder is relatively uncommon among the general population.

‘Our analysis confirms the association and indicates that the incidence of sudden cardiac death in patients with mitral valve prolapse is significant at 14 in 1000 per year,’ Dr Mahajan said.

Co-author Professor Prash Sanders added: ‘With one in five sudden cardiac deaths (SDC) occurring in people with otherwise normal hearts, this research provides insight into the need for further investigation of patients with mitral valve prolapse and high-risk conditions for serious and life-threatening cardiac arrhythmias.’ 

This comes after research released last month suggested a ‘harmless’ virus carried by half of adults increases a person’s risk of heart disease by a fifth.

Being infected with cytomegalovirus (CMV), which is a cousin of the herpes virus and spreads via contact or bodily fluids, makes a person 20 per cent more likely to ‘catch’ heart disease, according to a study by Brighton and Sussex Medical School.