An 80-year-old woman presented with dysarthria. Grade 3/6 pan-systolic murmur was noted. She did not have a fever and there was no history of infective endocarditis. Pontine cerebral infarction was observed on magnetic resonance imaging. Transthoracic echocardiography (TTE) indicated a 2.5×4.5-cm submitral aneurysm (SMA) in the lateral aspect of the mitral commissure on 2-chamber view (Figure A). Color Doppler showed a high-flow jet from the left ventricle (LV) to the SMA (Figure B) and an eccentric jet toward the left atrium (LA;
Figure C). On contrast-enhanced multi-slice computed tomography (CT), the SMA was located in the lateral aspect of the mitral valve, and under the LA appendage on 3D-CT (Figure D); and communicated with the LV and LA on multi-planar reconstruction (Figure E,F). No thrombus was observed in the SMA. We concluded that the cerebral infarction might be due to lacunar infarction. Surgery was too dangerous due to the level of frailty.
SMA is a rare cardiac anomaly. In a recent report the prevalence of LV aneurysms was <0.1%; mean patient age was 34 years; and 33% were found in the submitral location, and they have been described predominantly in African populations.1
In Japanese patients, SMA is an extremely rare condition. According to current consensus, SMA is due to congenital weakness of the fibrous annulus of the mitral valve, leading to outpouching of the LV wall.1
Mitral regurgitation is a common presentation. Other clinical symptoms include thromboembolism, ventricular arrhythmia and spontaneous rupture.1
TTE is standard for diagnosis, but accurate diagnosis was done on CT in the present case. Multimodality imaging can facilitate detailed evaluation of SMA. The definitive treatment is surgery. Appearance of symptoms or enlargement of SMA are one of the indications for surgery.
We encountered an extremely rare case of SMA with LA communication in a Japanese patient diagnosed on multimodality imaging.
