This page is for patients who are seen at the National Hospital for Neurology and Neurosurgery, who have a diagnosis of mitochondrial disease. This page outlines the importance of having your heart checked as part of your care.
Mitochondria are the small structures in cells that produce energy. Mitochondria are sometimes called the batteries or the power houses of the cell. The energy produced by the mitochondria is used for essential cell function. Each cell in our body has a nucleus, also called the control centre for the cell. The genetic code for individual’s characteristics such as height, eye colour sits in the cell nucleus. This genetic code is also called DNA, and the DNA is packaged into units called genes.
Some of these nuclear genes work with the mitochondria to control things like repair and maintenance of the mitochondria. Mitochondria also have a small number of their own mitochondrial genes (DNA) these are separate for the nuclear DNA. Mitochondrial diseases are a group of rare genetic conditions which are commonly caused by changes in the mitochondrial genes (DNA).
Mitochondrial disease can also be caused by a change in the genes in the cell nucleus that work with the mitochondria. Mitochondrial disease affects each person differently and can cause a wide range of symptoms. Please speak with the Mitochondrial disease clinic staff if you have any questions.
The heart is a large muscle containing many mitochondria. Mitochondria are needed to make the energy that the heart needs to work. If the mitochondria cannot make enough energy, this can start to affect the way the heart works. Not everyone with Mitochondrial disease will have heart involvement. Remember everyone is different.
Heart checks are done by a heart specialist (Cardiology) team. Heart checks are important because they help to check how the heart is working. Regular heart checks help to identify any changes in the way the heart is working early. This helps the heart specialist to start any treatment or medication that maybe available as early as possible.
Heart involvement is more common in certain types of mitochondrial disease, and so the team may not always ask that you have your heart checked. Please speak with the Mitochondrial disease clinic staff if you have any questions.
Often people will be unaware of any changes with their heart. Common signs of heart involvement can include the following: light-headedness, fainting, racing/pounding heartbeat, chest pain, clamminess, irregular heartbeats or shortness of breath. If you experience any of these symptoms, please speak to your GP and let the mitochondrial team know so we can arrange for screening tests.
There are a range of heart problems that can be seen in people with Mitochondrial disease. These can include the problems listed below. Remember, not everyone with Mitochondrial disease will develop problems with their heart. Please speak with the Mitochondrial disease clinic staff if you have any questions.
Heart problems that can be seen in people with Mitochondrial disease include problem with the heart muscle or heart rhythm:
Cardiomyopathy: This is a problem with the heart muscle. The muscle can become enlarged rigid or thick or in some cases dilated (stretched). This makes it less efficient at pumping blood around the body. It can also cause abnormal heart rhythms.
Cardiac Arrhythmias: these are problems with the way the heart beats – it may beat too fast, too slow, or with missed or extra beats.
Heart Block: is an example of a problem with the heart’s rhythm. Heart block is where there is a delay in the normal electrical messaging in the heart which changes the way it beats. There can be a very slow heartbeat which can reduce the amount of oxygen getting around the body.
It is your choice if you decide not to have your heart checked. This may mean that the doctors who look after you are not able to identify a heart problem that could be treated. Your care will not be affected in any other way if you choose not to have your heart checked.
If your heart checks find a change in the way your heart is working, you will be able to discuss treatment options with the heart specialist. You will be given a choice about whether to start treatment. You may be able to try different types of medication (for example, if one tablet does not suit you).
You do not need to do anything special to prepare for either test. You can eat and drink as normal. You should take your medicines as normal.
We want to involve you in all the decisions about your care and treatment. If you decide to go ahead with treatment, we must ask for your consent. You will have an opportunity to talk with your heart specialist about the risks, benefits, and alternatives before starting any treatment. If you are unsure about any aspect of your proposed treatment, please don’t hesitate to speak with your heart specialist or a member of the Mitochondrial disease team.
Electrocardiogram (ECG): ECG is a simple test used to check whether your heart is beating normally. It is a painless test and involves having sticky pads placed on your chest; the cables pick up the electrical activity from your heart and record it on a special graph. You may need a longer 24-hour monitor to pick up slow or fast heart rhythms over time, which are not picked up by the ECG. This monitor is called a ‘Holter’ monitor.
Echocardiogram (echo): An echo is a test that shows us pictures of your heart and surrounding blood vessels. This helps us check the thickness of the heart muscle, as well as the heart’s pumping ability.
Cardiac Magnetic resonance imaging (MRI): An MRI scanner is a large tube that contains powerful magnets. You lie inside the tube during the scan, and the MRI produces detailed images of the inside of your heart. The cardiac MRI helps us to take a very detailed look at the structure of your heart.
If the tests show any problems with your heart, you may be asked to start on some medications. These can include:
Beta‐Blockers: these work by blocking the actions of hormones such as 6 adrenaline, this will slow down the heartbeat and make it beat with less force.
Angiotensin‐Converting Enzyme (ACE) Inhibitors: these work to lower your blood pressure by relaxing your blood vessels and reducing the strain on your heart.
Pacemaker: this is a small device about the size of a matchbox, placed in the chest or abdomen. This device will keep your heart beating regularly. Most pacemakers have a special sensor that recognises your body’s needs and adjusts your heart rate according to its needs.
All treatments are more effective if started early, therefore we screen many patients with mitochondrial disease; even they don’t have any signs of heart problems. Many of the potential heart problems described, and their symptoms, can be treated effectively if identified early.
Regular monitoring of the heart is an important way of identifying any changes early, so that any treatment can be started.
- Bates, M.G., Bourke, J.P., Giordano, C., d'Amati, G., Turnbull, D.M. and Taylor, R.W., 2012. Cardiac involvement in mitochondrial DNA disease: clinical spectrum, diagnosis, and management. European heart journal, 33(24), pp.3023-3033.
- Jones, D.M., Schafer, A.M., Bates, M.G.D., Bourke, J., Gorman, G.S., Turnbull, D.M., McFarland, R. and Ng, Y.S., 2018. P3462 Cardiac manifestations in adult patients with mitochondrial disease arising from nuclear gene mutations: do they benefit from cardiac surveillance?. European Heart Journal, 39(suppl_1), pp.ehy563-P3462.
- Ng, Y.S., Grady, J.P., Lax, N.Z., Bourke, J.P., Alston, C.L., Hardy, S.A., Falkous, G., Schaefer, A.G., Radunovic, A., Mohiddin, S.A. and Ralph, M., 2016. Sudden 7 adult death syndrome in m. 3243A> G-related mitochondrial disease: an unrecognized clinical entity in young, asymptomatic adults. European heart journal, 37(32), pp.2552-2559.
- Lim, A.Z., Jones, D.M., Bates, M.G., Schaefer, A.M., O'Sullivan, J., Feeney, C., Farrugia, M.E., Bourke, J.P., Turnbull, D.M., Gorman, G.S. and McFarland, R., 2021. Risk of cardiac manifestations in adult mitochondrial disease caused by nuclear genetic defects. Open Heart, 8(1), p.e001510.
Mitochondrial Specialist Nurse
National Hospital for Neurology and Neurosurgery
Box 102
London WC1N 3BG
Switchboard: 0845 155 5000 / 020 3456 7890
Direct Line Telephone: 020 3448 8009
Fax: 020 3448 3633
Email: uclh.enquiry.mitochondrialservice@nhs.net
The nurse specialist is available from Monday to Friday (excluding Bank Holidays)
Outpatient clinics for the Rare Mitochondrial Disorders clinic are held on the 3rd floor of the Royal Hospital for Integrated Medicine