Shake, Rattle and Snore

Obstructive sleep apnoea — the ‘hidden’ sleep syndrome associated with heart rhythm disturbances and cardiovascular disease

We spend a third of our lives asleep so it is logical that if we neglect our health at night we will suffer the consequences during the day.

Dr David Wilson Cardiology Clinical Research Fellow University Hospitals Southampton NHS Foundation Trust
Dr David Wilson
Cardiology Clinical Research Fellow
University Hospitals Southampton NHS Foundation Trust

What is OSA?

Obstructive sleep apnoea (OSA) is a common but usually undiagnosed condition. Up to one in four middle-aged people are affected. Most people who have it don’t know about it — but there are some clear tell-tale signs. It is caused by the soft tissues around the throat and windpipe collapsing and temporarily blocking the windpipe during sleep. Therefore, if you are overweight and have more soft tissue around the neck then you will be susceptible. This causes the amount of oxygen in the blood to plummet (essentially through temporary suffocation) and this is a potent trigger for huge spikes in blood pressure and distressed activation of the ‘fight’ response in the body’s nervous system. This pattern can repeat itself every few minutes during sleep and result in more than just a poor night’s sleep — as we shall see later.

What are the symptoms of OSA — are you sleepy all the time?

Typically, someone with untreated OSA awakes from sleep feeling shattered — sometimes described “as if they have been run over by a lorry”. They often feel tired during the day and can fall asleep easily — at work, on the train or bus on the sofa or more worryingly whilst driving. Individuals with OSA usually snore loudly at night and can stop breathing for a few seconds, waking up snorting or gasping — this pattern is most often observed by partners of people with OSA!

How is OSA linked to heart disease, stroke & heart rhythm disturbances?

There is a clear association between OSA, heart disease, stroke and heart rhythm disturbances (particularly atrial fibrillation). We know than OSA causes huge surges in blood pressure, changes in the lining of the blood vessels supplying the brain, makes the blood stickier than normal as well causing enlargement of the heart chambers — this all puts a lot of sudden excess stress on the cardiovascular system. These factors contribute to the increase in risk of stroke associated with OSA. OSA is also associated with heart rhythm disturbances such as atrial fibrillation (which can cause stroke), bradycardias (slow heart rhythms) and tachycardias (fast heart rhythms) — and some of these are potentially fatal. OSA has also been shown to worsen atherosclerosis (hardening or furring up of the arteries), which leads to heart attacks, strokes and other cardiovascular problems.

Atrial Fibrillation (AF) and obstructive sleep apnoea

This is an important point to emphasise. Many of our middle aged patients who are developing atrial fibrillation (AF) fall into a life-long pattern of increasing medications and invasive treatments such as ablation. AF (especially when combined with OSA) can be viewed as a dietary and lifestyle illness — you can avoid unnecessary medications by addressing the underlying problem!

What can I do to make things better?

The good news is that OSA is largely preventable — in the majority of situations though diet and lifestyle changes. Simple measures such as stopping smoking, reducing alcohol (especially before bedtime as alcohol is a sedative and will exacerbate OSA), losing weight (and the soft tissues around the neck and belly), avoiding sleeping on your back or making changes to the type of medication that are prescribed for you can make a big difference.

What are the other options?

In the vast majority this can be treated by simple dietary and lifestyle change with a focus on weight optimisation.

Continuous positive airway pressure (CPAP) masks are very effective and consist of a tight fitting mask which is connected to a pressure generator that you sleep with at night. By splinting open the airways through positive pressure they prevent airway obstruction at night. However they can take some getting used to. Other measures include surgery to correct structural problems in the mouth and throat but these invasive treatments are reserved for the most advanced cases.

Real life example — can you relate to any of this?

Mr J is a 49-year-old manager of a hardware store. He used to enjoy playing rugby but hasn’t been that active since twisting his knee in a game 10 years ago. He has however continued to drink with his old team mates and has realised he is now heavier than he ought to be, with a beer belly and thick neck. His GP diagnosed him with high blood pressure last year and started him on tablets (Ramipril and Bendroflumethiazide). His GP is also concerned about his weight and his risk of diabetes and has advised him to ‘do more and eat less’ — however, he finds it difficult to shift the weight.

Recently, he has noticed he has been having palpitations — which he describes as having a butterfly in his chest. His GP performs an ECG and diagnoses him with atrial fibrillation. He starts him on a Beta-blocker and Warfarin (because of the risk of stroke) and refers him for a scan of his heart (echocardiogram) and to see a Cardiologist.

Mr J is surprised when the Cardiologist starts asking him about his sleep as he can’t see the relevance to his palpitations. However, he does admit that his wife has complained a lot about his snoring — he’s been kicked out to the spare room more than once — and she has even had to prod him when he stops breathing! He completes a questionnaire about his sleep and the doctor explains that there might be a link between his sleep and his atrial fibrillation.

Three months later, Mr J is back at the Cardiologists for a review of his symptoms. Mr J has made some small changes to his diet, cut his drinking down significantly and has started cycling the 3 miles to work. He has lost 2 stone and feels great for it. He now has more energy and doesn’t feel so sleepy during the day. He loves waking up feeling refreshed and ready to go. The Cardiologist has explained that his blood pressure is much improved (and will probably be able to stop one of his tablets). His atrial fibrillation has also improved and if he keeps up the good work he won’t need to have an ablation (operation for heart arrhythmias) for his AF either.

Not only has he markedly improved his quality of life, he has also improved his future prognosis — reducing the risk of requiring more tablets, of on-going heart rhythm disturbances, heart attacks and stroke — all through simple (almost boring) evidence-based dietary and lifestyle changes.

Biography

Dr Wilson is a Specialist Registrar in Cardiology. His specialist interests include Cardiac Rhythm Management and Heart Failure.

David trained at the Manchester and in Lausanne, Switzerland. He qualified in 2003 and initially worked in the North West of England and London. In 2007 he moved to Bristol and was appointed a Specialist Registrar in Cardiology in 2008. In 2011 he worked as a Fellow in Wellington, New Zealand. He is currently undertaking a Doctorate in Medicine at the University of Southampton investigating sensing algorithms in subcutaneous implantable cardioverter defibrillators.

He is married and has 3 young children.

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