Case Report: Fortuitous discovery of cor triatriatum sinister in a young adult [version 1; peer review: 1 approved with reservations, 1 not approved]

Cor triatriatum is an extremely rare cardiac congenital malformation characterized by subdivision of the left atrium into two chambers. This division is due to the presence of an abnormal fibromuscular membrane interrupted by one or more openings that communicate the two chambers. The size and number of those orifices is variable, affecting the age of onset of symptoms and their severity. Our case describes the fortuitous discovery of this pathology in a young adult in her forties, following the finding of atrial fibrillation during a preoperative assessment of a strangulated hernia. The cardiac ultrasound allowed in our case to invoke the diagnosis, confirmed thereafter with an angioscanner. Surgical resection was not required in our patient who was put on medical treatment involving a beta-blocker to reduce atrial fibrillation and an anticoagulant treatment to decrease the thromboembolic risk, with a good clinical evolution. It seems therefore interesting to consider this uncommon pathology which may be latent for a long time, manifesting after some physiological or pathological situations.