Discussion

We discuss the presentation of a teenager with dyspnoea, diffuse oedema, and rash who was diagnosed with right ventricular endocardial fibrosis. Right ventricular endocardial fibrosis is an important cause of cardiomyopathy in younger patients, with a bimodal age distribution peaking at 10 and 30 years of age, and is more commonly seen in sub Saharan Africa. ^{Reference Mocumbi, Stothard, Correia-de-Sá and Yacoub3} The pathophysiology is not completely understood, and a variety of causative factors have been hypothesised, including diet, impoverished living conditions, infection, and environmental factors contributing to an inflammatory process resulting in endomyocardial injury and scar formation. ^{Reference Mocumbi, Stothard, Correia-de-Sá and Yacoub3} The clinical presentation of right ventricular endocardial fibrosis often includes facial oedema, cyanosis, abdominal distension and less commonly jaundice or arrhythmia. ^{Reference Mocumbi, Yacoub and Yacoub4} Typical echocardiographic findings include obliteration of the right ventricular apex, ventricular thrombi, endomyocardial plaques or patches, and restrictive filling pattern. ^{Reference Mocumbi, Ferreira, Sidi and Yacoub5} While a full review of this pathology and management is beyond the scope of this report, our interactive session highlighted several key aspects.

Faculty and trainees from Texas had minimal prior exposure to this rare pathology. Thus, the proposed differential diagnosis included more common conditions, such as myocarditis and coronary artery disease. Reported cases of right ventricular endocardial fibrosis are highest in countries in Africa and Asia, with less frequent cases described from Venezuela and Brazil. ^{Reference Mocumbi, Stothard, Correia-de-Sá and Yacoub3,Reference Mocumbi, Yacoub and Yacoub4,Reference Puigbo, Combellas and Acquatella6,Reference Da Costa, Moraes and Rodriques7} Cases in Europe and the United States are exceedingly rare and typically seen in immigrants from endemic regions. ^{Reference Sutter, Suboc and Rao8,Reference Kumar, Prabhakar, Fawzy, Al Halees and Duran9} In endemic countries, right ventricular endocardial fibrosis is a leading cause of heart failure in young adults. A 2008 study from Mozambique found a 20% prevalence in screened individuals. ^{Reference Mocumbi, Ferreira, Sidi and Yacoub5} Thus, U.S. cardiology providers and trainees should remember to consider this diagnosis in younger immigrant patients presenting with new-onset heart failure.

Management options for right ventricular endocardial fibrosis are limited, irrespective of the clinical setting. Medical therapy addresses heart failure symptoms with medications including diuretics, renin-angiotensin-aldosterone system blockers, digoxin, beta-blockers, anticoagulants, and corticosteroids. ^{Reference Mocumbi, Stothard, Correia-de-Sá and Yacoub3} Many patients show improvement in symptoms, but ongoing pleural and pericardial fluid accumulation can be challenging, as in this patient. The patient ultimately underwent surgical endocardial resection with bidirectional Glenn operation, to offload systemic venous return in the setting of poor right ventricular function. Surgical options, including endomyocardial resection with or without atrioventricular valve replacement, have a relatively high mortality with 10-year survival of 70%. ^{Reference Schneider, Jenni, Turina, Turina and Hess10} Alternative surgical techniques include partial endocardial resection, valve preservation techniques, and total cavopulmonary connections. ^{Reference Mocumbi, Stothard, Correia-de-Sá and Yacoub3,Reference Kumar, Prabhakar, Fawzy, Al Halees and Duran9}