A Rare Presentation of Left Ventricular False Tendon Across the Mitral Valve Connecting the Left Atrium and Ventricle: A Case Report.

Background: Cardiac False tendons are anatomical variants of fibromuscular structures that generally should not exist in the heart. The left ventricular tendon, which crosses the left ventricular cavity, is typically seen in most cases of false cardiac tendons; however, our case differs from other cardiac false tendons. This case involves a fibrous tendon that spans the mitral valve, connecting the left atrium and ventricle. This unusual presentation has only been documented once. Based on our knowledge and research, this is the first documented occurrence in the United Arab Emirates and the second incident worldwide.

Case Presentation: A 12-year-old girl presented to an outpatient clinic with palpitations as her main complaint. After transthoracic echocardiography, it was suggested that a false tendon was passing through the mitral valve to connect the left atrium and left ventricle. We performed a transesophageal echo to confirm the diagnosis, and the results were identical to those of the transthoracic echocardiography. Since the uncommon false tendon only caused mild symptoms, an extensive multidisciplinary meeting was held, and we opted to manage the patient conservatively and monitor them annually at the outpatient cardiology clinic.

Conclusion: In this uncommon case presentation, accurately diagnosing the condition and establishing a treatment and follow-up plan are crucial for understanding similar cases in the future. This variant of false tendons across the mitral valve appears to be a benign anatomical structural variant, comparable to other false tendons in the heart. Currently, there is insufficient evidence to link false tendons to increased cardiac morbidity and mortality.