Endocardial fibroelastosis (EFE) is a rare heart (cardiac) condition which usually begins in infancy or early childhood. With EFE, the innermost muscular lining of the heart is thicker than normal because too much supportive connective tissue and elastic fibers grows. This situation causes an enlarged heart (cardiac hypertrophy), especially of the left ventricle (one of the four chambers of the heart). In rare cases, the left ventricle is small and the right ventricle is enlarged. The ventricles are the pumping lower chambers of the heart. In addition, in about 50% of the cases of EFE, one of the valves in the heart (which control the flow of blood between heart chambers) does not work correctly. All of this makes it hard to the heart to pump blood, and if left untreated, can lead to congestive heart failure.
Symptoms of EFE include difficulty feeding, excessive sweating, breathlessness, slow growth, fatigue, and possible abdominal pain. Symptoms usually appear between 4-12 months of age. The cause of most cases of EFE is unknown although infection of the heart during pregnancy or early infancy may be a factor. About 10% of EFE cases run in families. The X-linked type involves the EFE2 gene. The autosomal recessive type involves the gene EFE1.
In recent years, diagnosis occurs more frequently during pregnancy. Whether diagnosis occurs before or after birth, blood tests, electrocardiogram (EKG), certain types of ultrasounds, and MRIs may be used for diagnosis. Treatment usually includes different medications to help the heart work better, but depends on how much heart damage is already present. In advanced cases, a heart transplant may be necessary for the child. Research is ongoing, so talk to your child’s pediatric cardiologist (heart doctor for children) for the most current treatment options. Genetic counselors and support groups are also good sources of information and can help connect you with other families affected by EFE.