Mitral regurgitation secondary to mitral arcade in two brothers

BACKGROUND: Mitral arcade (MA) is a rare entity, mostly reported in pediatric patients. To date only 8 isolated adult cases have been reported in literature. We report the first example of familial mitral arcade in two brothers. CASE: Brothers, 16 and 18 years old, with short chain acyl CoA deficiency were evaluated for asymptomatic cardiac murmur. They were both vitally stable and noted to have 2/6 systolic murmur best heard over left lower sternal border. EKG notable for left atrial enlargement. Transthoracic echocardiogram (TTE) revealed direct attachment of the papillary muscles to the mitral valve leaflets, i.e., MA (marked in images A, B, C and D) and mild mitral regurgitation (MR). Three dimensional TTE and cardiac magnetic resonance imaging (MRI) confirmed findings of MA. DECISION-MAKING: Patients with MA present with congestive heart failure from valvular regurgitation due to limited mobility of the mitral leaflets. It can cause premature death hence all prior reported cases have been in the pediatric population. Diagnosis is made primarily by TTE. Monitoring by serial TTE is advised and if regurgitation progresses to severe MR, surgical repair or replacement is warranted. Percutaneous approaches have not been utilized yet for treatment. CONCLUSIONS: In young patients with idiopathic MR consideration should be given to MA as a possible etiology. Since our series indicates a familial incidence hence family screening is recommended