Left Ventricular Non-Compaction

What is Left Ventricular
Non-Compaction (LVNC)?

Left-ventricular non-compaction cardiomyopathy (LVNC) is a condition that affects the muscular wall of the left ventricle (bottom part) of the heart. LVNC can occur as an isolated heart condition, or with other heart problems. Sometimes trabeculations can be a normal finding in healthy people and not considered disease. LVNC usually occurs during the development of the heart before a person is born, but can develop after birth.

This page focuses on inherited LVNC, but people with other kinds of LVNC may find this useful.

During development prior to birth, the heart muscle will begin as loosely formed muscle layers. They then begin to bind together tightly to make a thick layer of muscle that is firmly held together. LVNC interrupts this normal development, causing the heart muscle to be spongy and grooved, with “finger-like” structures (trabeculations) projecting into the left ventricle.

These changes impact the heart in two ways:

    • Since the heart muscle is formed differently, the heart muscle is weaker and may not pump blood effectively around the body. 
    • The finger-like structures (trabeculations) may affect the heart’s electrical activity, causing irregular or unusual heart rhythms (arrhythmias).
Family members are at-risk of developing LVNC, so it is important to monitor the heart in these individuals.
Comparison of a healthy heart and a heart with Left Ventricular Non-Compaction. The healthy heart on the left has four chambers: 2 atria and 2 ventricles. Each chamber of the heart is surrounded by muscle which has a healthy size and structure. The heart on the right indicates a heart with Left Ventricular Non-Compaction, the heart has 4 chambers surrounded by muscle. However, the muscle towards the bottom of the heart is thick and has finger shaped projections into the chamber.

Symptoms of LVNC are varied. Some people with LVNC may never experience any symptoms, while others may experience:

  • Shortness of breath (dyspnoea)
  • Swelling (oedema) in the feet, legs, or abdomen (belly)
  • Dizziness or lightheadedness (presyncope)
  • Chest pain (angina)
  • Fainting or loss of consciousness (syncope)
  • Fluttering / pounding in the chest (palpitations)
  • Abnormal heartbeats (arrhythmias)
  • Fatigue (lethargy)

In serious but rare cases, LVNC can lead to heart failure, or sudden cardiac death. There are often no obvious symptoms prior to a sudden death.

LVNC can be diagnosed by a cardiologist (heart doctor), and is usually diagnosed through testing that checks how well your heart is working. Your cardiologist may also repeat these tests as part of your on going management.

Testing may include, but is not limited to:

Image describes the different test types to diagnose cardiomyopathy. Taking a family history: Usually a three generation family history will be taken to find any clues to whether your cardiomyopathy runs in your family. You will typically be asked about family members' age, their health and if they have died at what age and the cause of death. Electrocardiogram (ECG): An ECG is a recording of the electrical activity of your heart, and can identify any unusual heart rhythms or extra heartbeats. The test involves placing ECG nodes (stickers) across your chest, arms and legs, and takes 5 minutes to complete. Echocardiogram (Echo): An echocardiogram (Echo) looks at the structure, size, and function (contraction and blood flow) of your heart. An echo uses wave sounds (ultrasound) to make a picture of your heart. This test takes around 30-40 minutes. Exercise stress test (Stress ECG): This test is done while exercising to see how your heart responds when it has to work harder than normal. For this test you will have an ECG while either on a treadmill or a bike. You will start the exercise test at an easy pace and increase the level of exertion. This test takes about 30-40 minutes to complete. Holter Monitor: A Holter monitor is a small device that records the heart’s electrical activity over a few hours or days. The device can be carried around your neck or waist and is connected to ECG electrodes (small patches that will stick to your chest). The monitor will take approximately 15 minutes to fit and will need to be returned at the completion of the test. Cardiac Magnetic Resonance (CMR) Imaging: CMR imaging takes detailed pictures of your heart structure and can see any changes to the tissues that make up the heart muscle. CMR looks at parts of the heart that may not be clearly visible on other tests such as an echocardiogram. You will lie very still on a bed that moves into a large cylinder (MRI machine). The scan takes approximately 45 minutes.

Our bodies are made up of millions of cells. Each cell contains a copy of our genetic information. Our genetic information is the instructions for our body deciding how we will grow and function. Each instruction is called a gene. We have two copies of all our genes.

We share our genetic information with our families as we receive half our genetic information from each of our parents.

In LVNC, one copy of a gene that is involved in your heart function may contain a genetic change (variant) that stops the heart from working as it should. The genetic variant changes the instructions sent out to the body and may cause your cardiomyopathy.

Example of gene changes leading to cardiomyopathy. Left example shows two copies of the same gene one has a change which leads to cardiomyopathy. This is what the genetics of someone with cardiomyopathy would look like. Right hand side shows two genes without a cardiomyopathy gene change. Showing what the genetics of someone unaffected by cardiomyopathy would look like.

LVNC is best managed by a team of healthcare professionals. This may include your GP, a cardiologist, a psychologist, and a cardiac genetic counsellor. Each member of your healthcare team plays a different and important role in caring for you, and your family. Management of your cardiomyopathy is very personal, your management plan will likely be different from other members of your family with the same diagnosis. There are a number of factors that go into personalising your management plan. Some of these are: age, current symptoms, how severe your disease is, your family history, and your specific type of cardiomyopathy.