Endocardial fibroelastosis
Overview
EFE refers to a pronounced, diffuse thickening of the ventricular endocardium and presents as unexplained heart failure in infants and children. The disease can be primary or secondary to various congenital heart diseases, most notably hypoplastic left heart syndrome, aortic stenosis, or atresia. The 2 pathologic forms of primary EFE include dilated, which is most common, and contracted. Primary EFE is not associated with any significant structural anomaly of the heart. Secondary EFE is associated with other congenital heart diseases. Once regarded as a common cause of unexplained heart failure, EFE is now considered rare.
Symptoms
Breathlessness Cough Wheezing Feeding difficulty Excessive sweating Failure to thrive Recurrent chest infections (20%)
Causes
EFE has two distinct genetic forms, each having a different mode of inheritance. An x-linked recessive form, and an autosomal recessive form have both been observed. There is also some evidence that viral infection may play a role as a cause or trigger
Diagnosis
Blood tests: * Blood urea and creatinine * Blood count * Autoantibody profile including anti-Ro and anti-La7,8 * Blood culture tests indicated for management of acute episodes Chest X-ray: * Cardiothoracic (CT) ratio exceeds 0.65 in 50% of patients5 * Left lower lobe atelectasis is seen in 25% of patients * The cardiac silhouette is often globular * Pulmonary venous congestion is common ECG: * Tall R waves * Deep Q waves * T-wave inversion or flattening in the left precordial or inferior lead * Findings depict LV hypertrophy * Right axis deviation and isolated right ventricular hypertrophy (more common in the first few weeks of life)
Prognosis
Primary EFE prognosis is relatively poor, although the condition is not universally fatal; 4 years survival of 77%.5 Infants presenting with acute failure almost always die from the acute episode, unless they receive a transplant.13 Those with a chronic presentation have a 30-40% mortality rate from resistant heart failure. Acute CHF becomes progressive CHF. It terminates in death within weeks, usually in the first 6 months of life. Progressive CHF causes one third of patients' conditions to deteriorate leading to death.
Treatment
The principles are the same as treatment of chronic cardiac failure. * Any acute exacerbations are often precipitated by respiratory infections. * Early and prolonged treatment with digoxin is suggested. * Therapy should be continued for several years after the symptoms disappear, as cessation of the drug may result in acute cardiac failure.5 * Steroid therapy (dexamethasone) has been shown to cure fetal EFE and AV conduction delays associated with maternal anti-Ro and anti-La antibodies.12 * Supportive measures for acute failure and exacerbations may be required e.g. treatment of infection and anaemia. * Thromboembolic complications may require anticoagulation.