Cardiomyopathy: disease of the heart muscle

Understanding cardiomyopathy

Cardiomyopathy is a disease of the heart muscle itself, rather than of the heart's arteries, valves or electrical wiring, although it can affect all of these over time. The heart muscle (the myocardium) normally contracts strongly and relaxes fully with every beat, so the heart can fill with blood and then pump it out efficiently. In cardiomyopathy, the muscle's structure changes in a way that interferes with this cycle — it may stretch and weaken, thicken abnormally, or become stiff. The result, whatever the type, is a heart that struggles to pump or fill as well as it should.

There are several recognised patterns. Dilated cardiomyopathy is the most common: the heart's main pumping chamber (the left ventricle) stretches and enlarges, and the muscle wall becomes thinner and weaker, so each contraction pushes out less blood than it should. Hypertrophic cardiomyopathy is often inherited: the muscle wall thickens abnormally, sometimes unevenly, which can make the heart stiff and, in some people, narrow the pathway blood takes on its way out of the heart. Restrictive cardiomyopathy is less common: the muscle becomes stiff and loses its ability to relax and fill properly between beats, even though it may squeeze normally. A distinct form, peripartum cardiomyopathy, develops in the last month of pregnancy or the months after delivery, when the heart weakens for reasons not fully understood — it is uncommon but important to recognise early, since new breathlessness or swelling after childbirth is easy to mistake for normal postpartum tiredness.

What cardiomyopathy feels like

Symptoms depend on the type and how advanced it is. Some people have no symptoms for years and are found to have cardiomyopathy only through family screening or an unrelated test. These are common descriptions patients use, offered to help you put your own experience into words for a clinician — not a checklist for diagnosing yourself.

• ●Breathlessness, especially on exertion or lying flat
• ●Unusual tiredness or reduced ability to exercise
• ●Palpitations — a fluttering, racing or pounding heartbeat
• ●Dizziness or fainting, particularly during exertion
• ●Chest discomfort or tightness
• ●Swelling of the ankles, feet or abdomen
• ●New breathlessness or swelling in the weeks after childbirth

Because some types of cardiomyopathy are inherited, fainting during exercise or a family history of unexplained collapse or sudden death at a young age are taken particularly seriously, even without other symptoms.

What causes cardiomyopathy

Cardiomyopathy can be inherited, triggered by another illness, or have no identifiable cause found even after thorough assessment.

Inherited causes

Many cases, especially hypertrophic cardiomyopathy, run in families because of a gene change passed down from a parent. This is why, once someone is diagnosed, close relatives are often offered screening — even if they feel completely well.

Caused by another illness or exposure

• ●Longstanding, poorly controlled high blood pressure — forces the heart to work harder over years, thickening or eventually weakening the muscle
• ●Viral infection of the heart muscle (myocarditis) — can weaken the muscle during or after the infection
• ●Heavy or long-term alcohol use — directly weakens heart muscle over time
• ●Pregnancy and the period after delivery — peripartum cardiomyopathy
• ●Certain cancer treatments — some chemotherapy medicines can affect heart muscle
• ●Thyroid disease and other hormonal or metabolic conditions

Unknown cause

In a substantial number of people, no clear cause is found even after full assessment. This is still called cardiomyopathy and is managed the same way, based on how the heart is affected rather than on the underlying trigger.

Who is more likely to develop cardiomyopathy

These factors make cardiomyopathy more likely, or make it especially important to be assessed promptly:

• ●A family history of cardiomyopathy, unexplained fainting, or sudden death at a young age
• ●High blood pressure — very common in Nigeria and often undiagnosed
• ●Pregnancy, particularly the last month and the months after delivery
• ●Heavy or long-term alcohol use
• ●Obesity and diabetes
• ●A recent significant viral illness with chest symptoms
• ●Previous cancer treatment affecting the heart

What happens if cardiomyopathy goes untreated

Cardiomyopathy is a long-term condition, and its course varies widely between people; recognising it and starting treatment early meaningfully improves outcomes.

Heart failure. As the muscle weakens or stiffens further, the heart struggles to meet the body's demands, causing breathlessness, fatigue and fluid retention.

Arrhythmias. Abnormal heart muscle disrupts the heart's electrical pathways, which can cause palpitations or more serious rhythm disturbances.

Sudden cardiac death. Rarely, a dangerous rhythm arising from diseased heart muscle can stop the heart pumping effectively without warning — the main reason some people with cardiomyopathy are offered a protective device.

Blood clots and stroke. When the heart pumps poorly, blood can pool inside its chambers and clot; a clot that breaks free can travel to the brain or elsewhere in the body.

Valve leakage. An enlarged, stretched heart can pull its valves out of shape, allowing blood to leak backwards and adding to the heart's workload.

How Cardiocare finds the cause

The right pathway depends on your symptoms, examination, family history and overall health. It typically draws on some or all of the following:

• 01
  History and examination. Your symptoms, personal and family history, including any relatives who fainted unexpectedly or died suddenly and young.
• 02
  12-lead ECG (electrocardiogram). A painless recording of the heart's electrical activity, which can show patterns typical of muscle thickening or strain.
• 03
  Echocardiogram. A painless ultrasound scan that shows chamber size, muscle thickness, pumping strength and valve function — the central test for diagnosing and classifying cardiomyopathy.
• 04
  Blood tests. Including markers of heart strain, thyroid function, and other tests directed by your history.
• 05
  Holter or event monitoring. A portable ECG recorder worn for a day or longer, to catch rhythm disturbances that come and go.
• 06
  Cardiac MRI. Detailed imaging that can characterise the heart muscle further for selected patients.
• 07
  Family screening and genetic assessment. Offered where an inherited cause is likely, so at-risk relatives can be checked even without symptoms.

How cardiomyopathy is treated

Treatment is matched to the type of cardiomyopathy, how the heart is affected, and your individual risk of rhythm problems — there is no single treatment that fits every case.

Lifestyle

Depending on the type, your team may advise limits on strenuous or competitive exercise, particularly in some forms of hypertrophic cardiomyopathy, alongside complete avoidance of alcohol where it may be contributing, and careful attention to salt and fluid intake if the heart is not pumping well.

Medicines, by class

Where medicine is needed, it is chosen by what it does, and your clinician will discuss the right option and dose for you:

• ●Beta blockers — slow and steady the heart rate and ease the heart's workload
• ●ACE inhibitors or ARBs — protect a weakened heart and reduce strain on the muscle
• ●Diuretics — help the body clear excess fluid when the heart is not pumping well
• ●Anticoagulants (blood thinners) — reduce the risk of clots forming inside a weakened or irregularly beating heart
• ●Anti-arrhythmic medicines — help control abnormal heart rhythms

Devices and procedures

Available through Cardiocare's cardiac catheterisation ("cath") laboratory and electrophysiology service:

• ●Implantable cardioverter-defibrillator (ICD) — for selected patients at meaningful risk of a dangerous rhythm, a device that can detect and correct it automatically
• ●Pacemakers — for rhythms that become too slow, or to help the heart's chambers beat in a more coordinated way
• ●Specialist procedures — for selected obstructive hypertrophic cardiomyopathy or advanced cases, further options can be discussed with the heart-team

Living with cardiomyopathy: everyday self-care

Cardiomyopathy is managed over the long term, and daily habits work alongside medicines and monitoring to protect the heart:

• ✓Take heart-failure and rhythm medicines consistently, even when you feel well
• ✓Avoid alcohol if it may be contributing to your condition
• ✓Follow the activity advice given for your specific type of cardiomyopathy
• ✓Ask whether close relatives should be screened
• ✓Discuss pregnancy plans with your team beforehand if you have, or are at risk of, cardiomyopathy
• ✓Report new or changing symptoms rather than waiting for your next routine visit
• ✓Keep specialist follow-up, even during periods when you feel entirely well

Preparing for your appointment

What to bring

• ✓A list of all medicines you take, including herbal and over-the-counter preparations
• ✓Any previous ECGs, echocardiogram reports or hospital letters
• ✓Details of any relatives with heart disease, unexplained fainting or sudden early death
• ✓Your HMO card or payment details and a valid means of identification

What we will ask

When your symptoms started, how they affect your daily activity, your personal and family history, and any pregnancy plans if relevant.

Questions worth asking us

• ●Which type of cardiomyopathy do I have, and what caused it?
• ●Do my relatives need to be screened?
• ●Do I need a protective device such as an ICD?
• ●What activity is safe for me?