The myocardium of fetuses with endocardial fibroelastosis contains fewer B and T lymphocytes than normal control myocardium

Endocardial Fibroelastosis: A Comprehensive Review

Endocardial fibroelastosis emerged as a challenging clinical phenomenon in the 1940s. It is characterized by an atypical proliferation of fibrous and elastic tissue within the heart and is primarily observed in childhood, occasionally displaying familial inheritance. While the precise cause remains elusive, various factors, including genetic, infectious, metabolic, autoimmune, oncologic, and medication-related influences, appear to play a role in its pathogenesis. The coexistence of endocardial fibroelastosis with multiple cardiac structural abnormalities manifests in symptoms of congestive heart failure and rhythm abnormalities. Despite its challenging diagnosis, various findings from ECG and imaging have proven beneficial in further evaluation of this condition. Finally, the treatment approach to endocardial fibroelastosis became complex due to addressing its concurrent cardiac abnormalities. Strategies for managing and preventing this condition are still under investigation. In this review, we intend to highlight the existing knowledge and illuminate future considerations regarding the etiology, diagnosis, and management of this disease.

Endocardial fibroelastosis and dilated cardiomyopathy - the past and future of the interface between histology and genetics

Endocardial fibroelastosis (EFE) signifies the pathological process by which collagen and elastin are focally or diffuse deposited in the endocardium of the left ventricle. The new layer causes left ventricular dysfunction sometimes with fulminant progression to heart failure. EFE is a major component in many congenital heart abnormalities but can also occur in the absence of heart malformations, either as a primary process or in response to cardiac injury. The endothelial–mesenchymal transition (EndMT) abnormalities seem to be main pathogenic factor in fibroelastosis development. The “gold standard” for diagnosis of primary EFE (pEFE) is the histological examination. Additionally, genetic studies may help to establish the natural course of the disease and to communicate prophylactic measures to family members of the affected child. Moreover, in the newborn, EFE takes the form of dilated cardiomyopathy (DCM) with unfavorable evolution. The proper management should be established considering negative prognostic factors, involving early transplantation, drug therapy and long-term follow-up.

A Case of Pediatric Heart Failure Caused by Anomalous Origin of the Left Coronary Artery from the Pulmonary Artery: Case Report and Literature Review

A female patient aged 3 months and 10 days was admitted to the cardiology department because of symptoms of heart failure. According to the echocardiography results, the patient received a diagnosis of primary endocardial fibroelastosis and was treated with γ-globulin, prednisone, digoxin, and diuretics. Coronary computed tomographic angiography and coronary angiography were performed as there was no improvement after 2 months of treatment. Finally, the patient received a diagnosis of anomalous origin of the left coronary artery from the pulmonary artery (ALCAPA). ALCAPA is a rare congenital heart defect that can cause severe heart failure during infancy, and is easily misdiagnosed clinically. In this report, we show the process of misdiagnosis of the case and consult the relevant literature, hoping to improve the understanding and early diagnosis of ALCAPA.

Comparison of Immune Profiles in Fetal Hearts with Idiopathic Dilated Cardiomyopathy, Maternal Autoimmune-Associated Dilated Cardiomyopathy and the Normal Fetus

The etiology of idiopathic dilated cardiomyopathy (iDCM) remains unknown. Immune therapies have improved outcome in fetuses with DCM born to mothers with autoimmune disease (aDCM). The purpose of this retrospective study was to compare the myocardial B and T cell profiles in fetuses and neonates with idiopathic DCM (iDCM) versus autoimmune-mediated DCM (aDCM) and to describe the normal cell maturation within the human fetal myocardium. Of 60 fetal autopsy cases identified from institutional databases, 10 had aDCM (18-38 weeks), 12 iDCM (19-37 weeks) and 38 had normal hearts (11-40 weeks). Paraffin-embedded myocardium sections were stained for all lymphocyte (CD45), B cells (CD20, CD79a), T cells (CD3, CD4, CD7, CD8) and monocyte (CD68) surface markers. Two independent, blinded cell counts were performed. Normal hearts expressed all B and T cell markers in a bimodal fashion, with peaks at 22 and 37 weeks of gestation. The aDCM cohort was most distinct from normal hearts, with less overall T cell markers [EST -9.1 (2.6) cells/mm(2), p = 0.001], CD4 [EST -2.0 (0.6), p = 0.001], CD3 [EST -3.9 (1.0), p < 0.001], CD7 [EST -3.0 (1.1), p = 0.01] overall B cell markers [EST -4.9 (1.8), p = 0.01] and CD79a counts [EST -2.3 (0.9), p = 0.01]. The iDCM group had less overall B cell markers [EST -4.0 (1.8), p = 0.03] and CD79a [EST -1.7 (0.9), p = 0.05], but no difference in T cell markers. Autoimmune-mediated DCM fetuses have less B and T cell markers, whereas iDCM fetuses have less B cell markers compared with normal fetal hearts. The fetal immune system may play a role in the normal development of the heart and evolution of dilated cardiomyopathy.