Dados do Trabalho

Título

COR TRIATRIATUM DEXTER IN A CHILD WITH DUCHENNE MUSCULAR DYSTROPHY

Apresentação do caso único

A 9-year-old male, the second child of three from a young and non-consanguineous couple. At two years old, he began to present weakness in the lower limbs, frequent falls, and myalgia associated with moderate exercise. He has a family history of dystrophinopathies: two brothers with DMD, one asymptomatic brother diagnosed with muscular dystrophy through neonatal screening, two maternal uncles and a first cousin diagnosed with Becker muscular dystrophy, and two maternal uncles with an undiagnosed muscular dystrophy. At the age of five, the child was admitted to the emergency department with this condition. On physical examination, he presented hypertrophy of the calves and pain upon local palpation, but could walk without assistance. His creatine phosphokinase (CPK) levels were 28,900 U/L. Subsequently, next-generation sequencing (NGS) of the DMD gene identified a pathogenic splicing variant DMD: c.3603+3A>T. The echocardiogram revealed the presence of a membrane dividing the right atrium into two cavities, one receiving systemic venous return (superior and inferior vena cava) and the other related to the tricuspid valve. This membrane has an orifice at its central portion, measuring approximately 6.4 millimeters, with mild flow acceleration and a mean gradient of 2.6 mmHg. The ejection fraction was 69.5%. The echocardiogram conclusion was Cor triatriatum dexter (CTD) with mild flow acceleration. Given these findings, surgery was recommended to treat the congenital heart disease.

Discussão

It is estimated that 59% of patients with some form of dystrophinopathy have cardiac dysfunction by the age of 10, and almost all present with cardiomyopathy in adulthood. Cor triatriatum is a congenital malformation first described in 1868. Being an embryonic period malformation, CTD is often combined with other congenital heart defects. Associations with chromosomal abnormalities and respiratory diseases are also described. This is the first report of an association between CTD and DMD. In the treatment of CTD, surgical intervention is recommended, as the presence of the atrial membrane can act as a site for thrombus formation and, consequently, trigger pulmonary embolism.

Comentários finais

There is a trend of increasing cases of patients with DMD with some cardiac dysfunction, considering that current support therapies are allowing a reduction in early deaths. Cor triatriatum is an extremely rare congenital heart malformation that had not yet been reported in DMD.

Referências

Braga, V.L.L.; Lima, D.P.; Mariano, T.C.; Lima, P.L.; Maia, A.B.; da Silva Meireles, W.W.; de Oliveira Pessoa, K.T.; de Oliveira, C.M.; Ribeiro, E.M.; Nóbrega, P.R.; et al. Higher Prevalence of Nonsense Pathogenic DMD Variants in a Sin-gle-Center Cohort from Brazil: A Genetic Profile Study That May Guide the Choice of Disease-Modifying Treatments. Brain Sci 2023, 13, 1521.
Church, W.S. Congenital malformation of the heart: abnormal septum in left auricle. Trans Pathol Soc (Lond) 1868, 19, 188-190.
Hussain, S.T.; Mawulawde, K.; Stewart, R.D.; Pettersson, G.B. Cor triatriatum dexter: a rare cause of myocardial infarc-tion and pulmonary embolism in a young adult. J Thorac Cardiovasc Surg 2015, 149, e48-e50.
Zanoni, M.T.; Cunali, V.C.A.; Chagas, V.C.A.; Silva, K.C.K.B.; Souza, F.M.; Araújo, C.L.M. Cor triatriatum: um caso raro e assintomático. Resid Pediatr 2020, 10, 20-22.

Palavras Chave

Cor triatriatum dexter; Duchenne muscular dystrophy; Neuromuscular diseases