From InterAction 95, Spring 2017
Our joint medical advisers, Prof Julia Newton and Dr Gregor Purdie, answer a reader's question about heart problems and M.E.
“I have had a particularly difficult year, with two clinic admissions for cardiac issues (they discovered I had Wolff-Parkinson-White Syndrome). I have read that M.E. can affect the heart; can you give me any more information?”
Prof Newton says: It has always been thought by some that M.E was a “small heart syndrome,” with studies using chest x-rays and cardiac ultrasound suggesting that the size of the hearts overall were small in M.E patients compared to controls.
As part of a published study looking at cardiac issues in M.E. (available online via the journal Open Heart (www.openheart.bmj. com), our research group has recently performed similar tests, but using state-of-the-art MRI technology. We’ve confirmed that hearts, particularly the big chambers of the heart called the ventricles, were smaller compared to a control group. In addition we also measured plasma volume, ie. all the fluid that was in the circulation,
and showed that the size of the chambers of the heart are associated with plasma volume, with lower plasma volume being associated with a smaller heart.
The most interesting finding leading on from that was that people with lower plasma volumes were more fatigued. This has subsequently led to an Action for M.E.-funded study, whereby we have been measuring cardiac volumes and autonomic function in response to expansion of the circulating volume. We have also had the lucky opportunity of adding onto the study MRI scans of the heart and brain to determine whether or not the original abnormalities we see are changeable with volume expansion. If this is the case, it represents a really important opportunity for improving fatigue and overall symptoms in M.E..
Sometimes people ask me whether or not postural tachycardia syndrome (PoTS) (see InterAction 94 p 36), which is a condition known to affect about 30% of people with a diagnosis of M.E., is a cardiac disorder. In fact it is not an abnormality of the heart as such, but rather an abnormality of heart rate. Studies to date do not suggest that those with PoTS have any structural heart disease.
The finding of Wolff-Parkinson- White Syndrome is really interesting – it is quite a common condition (and only rarely is it serious), and just because you have a diagnosis of M.E., it does not necessarily mean that you won’t get other conditions. I always try and emphasise to patients that if they have a new symptom, or a change in their symptoms, they should seek medical advice.
Dr Purdie says:As always, it is very important for your GP to gain a clear picture of the problem. In this situation, we are dealing with a problem of the rhythm of the heart, where the heart rate is irregular. A patient may firstly be aware of an irregular heartbeat, or a fluttering feeling in the chest. It can be momentary or more prolonged. There can be triggers, such as caffeine. There are a number of underlying heart conditions that can show themselves this way, and your GP will need to examine you and undertake the tests needed to assess the underlying cause.
This first thing a GP will need is a good history describing the symptoms. How often do they come, how long do they last? Is there anything that sets them off? Is there anything that helps to stop it? The fundamental examination is taking the pulse. It is also vital to listen to the heart, as some irregular rhythms can then be more clearly defined. An ECG – the heart tracing – can also be of value, but many irregular heart rhythms come and go. To help with diagnosis in these circumstances, there are monitors that patients ca take home, which measure the heart rate and rhythm over 24 hours.
Depending on the results, your GP may be able to treat the problem themselves or you may require a referral to a cardiologist for further assessment and treatment.
PoTS does need to be looked for in people with M.E. The simple stand test for PoTS can be undertaken in the GP surgery. This is a valuable screening investigation that would identify those people who require further specialist investigation, such as tilt table testing. For more information visit www.potsuk.org