Hypertrophic cardiomyopathy: symptoms, diagnosis and treatment

The BHF says most people with HCM have no symptoms or feel stable throughout their life, but some do have symptoms. Which symptoms you have depends on the area of heart muscle that is affected and the amount of thickening or stiffening.

The BHF says some people find their symptoms worsen in later life, possibly because the heart muscle has slowly become stiffer. The NHS adds that the heart changes can cause dizziness, chest pain, shortness of breath and temporary loss of consciousness.

• Chest pain.

• Light-headedness and fainting.

• Palpitations: feeling your heartbeat pounding or beating faster than usual.

• Shortness of breath.

• Fatigue, or getting tired easily.

• Swelling of the legs, feet, ankles and abdomen.

In HCM the heart muscle cells enlarge and the walls of the heart chambers thicken. The BHF says the left ventricle, the main pumping chamber, is almost always affected, and the septum (the wall between the left and right sides) can be affected too. How thick the muscle is, and how much of it is affected, differs from person to person.

The NHS explains that the heart chambers can be reduced in size so they cannot hold much blood, and that the walls cannot relax properly and may stiffen. The flow of blood out of the heart may also be obstructed.

Doctors may describe it as obstructive or non-obstructive. The BHF says obstructive HCM means blood flow from the heart is reduced by the thickened wall, which can cause more problems such as arrhythmias and valve regurgitation. In non-obstructive HCM, blood flow is not reduced by the thickening.

The BHF says there is currently no cure for HCM but treatments help control symptoms and prevent other health issues. What you need depends on how your heart is affected and which symptoms you have, and not everyone needs treatment. The NHS notes that some people have only a mild form that they can control with a few lifestyle changes.

• Medicines: the BHF lists diuretics, beta blockers and cardiac myosin inhibitors, which can reduce the work the heart does, control blood pressure and manage abnormal heart rhythms and other symptoms. The NHS adds medicines to prevent blood clots, such as anticoagulants, where needed.

• An implantable cardioverter defibrillator (ICD) or a CRT device if you are at risk of a life-threatening abnormal heart rhythm.

• A pacemaker to control the heart rate, or an LVAD to help the heart pump blood.

• Catheter ablation to treat some kinds of arrhythmia.

• Septal myectomy, a type of heart surgery that removes part of the thickened muscular wall. The NHS also lists an injection of alcohol into the heart to reduce part of the septal muscle in some people with obstructive HCM.

• The NHS says a heart transplant may be necessary as a last resort.

The BHF lists a physical assessment (listening to the heart and lungs, checking blood pressure and pulse, and asking about your medical history), an ECG, an echocardiogram, an exercise test and an MRI scan as the most common tests. The NHS also mentions a heart rhythm monitor worn for 24 or 48 hours and a detailed family tree drawn by specialists.

If HCM is suspected you may be offered a genetic test to look for a faulty gene. The BHF says that if one is found, your healthcare professional may ask to talk to close relatives, because they may have inherited it too.

The BHF says people with HCM may be more at risk of abnormal heart rhythms such as atrial fibrillation or heart block, and that there is a rare risk of a life-threatening rhythm that can cause cardiac arrest. It also lists endocarditis, an infection of the heart's inner lining, and a leaky heart valve (mitral regurgitation). To lower the endocarditis risk, your healthcare professional might recommend antibiotics before or after surgery or procedures.

Call 999 if you have sudden chest pain or discomfort that does not go away, pain that spreads to your arm, neck, jaw, stomach or back, or chest pain with sweating, sickness, light-headedness or shortness of breath. The NHS chest pain page gives these as signs of a possible heart attack. If you already have HCM, fainting, new or worsening symptoms should be reported to your cardiology team promptly; the BHF stresses telling your healthcare professional if symptoms get worse.

The BHF says many people with HCM feel fine, and those with symptoms find they are managed well with treatment and can have a good quality of life. A healthy lifestyle can help reduce the effects of symptoms and the risk of other health problems.

On work, the BHF says you should be able to continue, though you may not be able to do manual jobs involving strenuous activity. On exercise, it says you should be able to enjoy most activities, but not some competitive sports and high-intensity exercise. For driving, you should be able to continue, but you might not be able to drive a lorry, bus, HGV or commercial passenger vehicle. Discuss each of these with your healthcare professional.

The NHS lifestyle advice for cardiomyopathy in general is to eat a healthy diet, do gentle exercise, stop smoking, lose weight if overweight, avoid or reduce alcohol, get enough sleep, manage stress and keep conditions such as diabetes well controlled.

The BHF says that if you are a parent, sibling or child of someone who has HCM, it is recommended that you are seen at a specialist inherited heart conditions clinic for an assessment and a conversation about genetic testing and heart screening tests. The NHS says relatives can be tested for the same gene change and, if they have it, their condition can be monitored and managed early.

On the NHS, HCM is diagnosed and followed up by cardiology teams, with referral to an inherited heart conditions clinic for family assessment. Specialist heart procedures such as septal myectomy are delivered in NHS specialist centres.

Some people also see a private cardiologist for scans such as echocardiography or MRI. Whichever route you use, long-term monitoring and decisions about devices or surgery are usually made with a specialist who knows your family history.