CONCLUSIONS
In conclusion, AMVT is an important cardiac lesion that is usually discovered incidentally. This case was presented because of its rarity in childhood. We emphasize that AMVT should be kept in mind in the differential diagnosis of LVOT obstruction, especially in adult patients with chest pain, dyspnea, and systolic murmur. A comprehensive evaluation is required to determine the need for surgical intervention. Recently, 3D echocardiography has played a fundamental role in patients’ diagnosis, treatment, and follow-up. Congenital heart surgeons should be aware of the clinical and pathological features of AMVT to avoid overlooking them during surgery.