What is Left Ventricular Noncompaction?

In left ventricular non-compaction cardiomyopathy (LVNC), the lower left chamber of the heart, called the left ventricle, contains bundles or pieces of muscle that extend into the chamber. These pieces of muscles are called trabeculations. The left ventricle is jagged instead of compact, smooth and solid.

These trabeculations typically occur at the bottom of the heart called the apex but can be seen anywhere in the left ventricle. Individuals with LVNC may also have another type of heart muscle disease (hypertrophic cardiomyopathy, dilated cardiomyopathy or restrictive cardiomyopathy).

LVNC is largely a genetic condition. Most commonly, it affects only the heart, but it may also be associated with other heart muscle conditions or genetic, metabolic or mitochondrial disorders.

Effects and Symptoms

Many individuals with LVNC experience no symptoms. Those with heart failure or an abnormal heart rhythm may experience shortness of breath, fatigue, dizziness or light-headedness, fainting or palpitations.

Although some people with LVNC experience no symptoms, they may still be at risk for complications associated with the diagnosis. The most serious complication of LVNC is sudden cardiac arrest or sudden loss of heart function caused by a dangerously fast heart rhythm called ventricular tachycardia. Unless emergency treatments, including CPR and defibrillation, are initiated immediately after the onset of symptoms, sudden cardiac death can occur.

Most people with LVNC have a low risk for sudden cardiac arrest. However, it is important for anyone at risk to be followed by a cardiologist with experience in caring for individuals with cardiomyopathy.

Diagnosis

In those who do not have symptoms, physical examination may be normal and the diagnosis is made only by echocardiogram.

LVNC is being diagnosed more frequently in both children and adults secondary to increased awareness of the condition. The initial diagnosis may be made at any age and many patients often go undiagnosed until later in life. Genetic testing is also done in patients in which LVNC is clinically suspected and in first degree relatives of genetically confirmed cases.

Management and Treatment

Treatment in individuals with LVNC is focused on treating associated types of cardiomyopathy or poor heart function. Medications may be given to treat symptoms and prevent ongoing damage to the heart muscle. A blood thinner to prevent the formation of blood clots may also be recommended for some individuals.