A 37-year-old man was referred to our hospital for a suspected left ventricular outpouching with no complaint of any severe symptoms. The patient had a medical history of inferior-posterior myocardial infarction. Two-dimensional transthoracic and transoesophageal echocardiography revealed an outpouching of about 40 × 23 mm in size adjacent to the aortic root, which communicates with the left ventricular outflow tract through a small orifice beneath the aortic cusps (Panels A and B, star: outpouching). Colour Doppler flow imaging showed to-and-fro flow between the left ventricle and the outpouching, which exhibited a paradoxical motion (Panel C, Supplementary material online, Video S1). Real-time three-dimensional transoesophageal echocardiography revealed that the orifice (*) measuring 3 × 5 mm in size was located between the right-coronary and non-coronary cusps, i.e. the interleaflet triangle (Panel D, Supplementary material online, Video S2 and Figure S2: R, right-coronary cusp; N, non-coronary cusp). Subsequent computed tomography confirmed the presence of the outpouching, which was connected to the left ventricular outflow tract by a narrow neck (Panels E and F). Cardiac magnetic resonance also showed a dyskinetic outpouching (Panel G) and the absence of a myocardial layer in its wall. Based on these findings, the outpouching was diagnosed as a subaortic left ventricular diverticulum.
Because of the likely life-threatening complications of the diverticulum and the proximity of the orifice to the aortic cusps, open heart surgery was chosen for the patient. Surgery ratified the multimodality imaging findings, showing an aberrant chamber arising from the base of the aorta, and an orifice in the fibrous interleaflet triangle area (Panel H). The patient underwent successful pericardial patch closure of the orifice with no residual shunt. Histological examination of a resected specimen from the wall of the chamber demonstrated the presence of a dense fibrous tissue with no myocyte (Panel I), confirming the diagnosis of a diverticulum. The post-operative course was uneventful. A post-operative echocardiogram revealed a marked collapse of the diverticulum.
Cardiac diverticula are rare congenital heart anomalies, which seldom arise from the subaortic area, especially the fibrous interleaflet triangles. To our knowledge, this is the first report of subaortic left ventricular diverticulum identified by multimodality imaging including three-dimensional transoesophageal echocardiography, which plays a fundamental role in the choice of the surgical approach.
Supplementary material is available at European Heart Journal online.
The authors would like to thank Dr Ya Li for her help in editing the images.
This work was supported by the Sanming Project of medicine in Shenzhen [SZSM201412011].
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