Prenatal diagnosis of accessory mitral valve tissue in a fetus with persistent dysrhythmia

BACKGROUND: Accessory mitral valve tissue (AMVT) is a rare congenital cardiac anomaly that mainly diagnosed in the first decade of life. However, asymptomatic cases may not be diagnosed even up to adulthood. We report a fetus with AMVT to show the diagnostic ability of the fetal echocardiography for detection of this pathology in the prenatal period. CASE PRESENTATION: AMVT was diagnosed in a 26-week-old male fetus with persistent dysrhythmia. Dysrhythmia could not be aborted and controlled by sotalol till the third trimester evaluation. Apical left ventricular (LV) diverticulum was the additional finding in his fetal echocardiogram. After birth, he was in sinus rhythm and echocardiography confirmed the presence of AMVT, however, without any evidence of LV apical diverticulum. CONCLUSIONS: The diagnosis of AMVT in the prenatal period is possible by fetal echocardiography. SUPPLEMENTARY INFORMATION: The online version contains supplementary material available at 10.1186/s43044-022-00263-z.