A 54-year-old man was referred to our center for assessment after an episode of syncope and progressive dyspnea. Clinical examination and echocardiography revealed dextrocardia with situs inversus, and bilateral basal crepitations without bruits. Plain chest films disclosed only an increased cardiothoracic index. Transthoracic echocardiography provided incomplete information on cardiac anatomy, and multiplanar transesophageal echocardiography was performed. Transesophageal study in a four-chamber view (A) and longitudinal view (B) confirmed situs inversus (Figure) and defined cardiac anatomy and function: atrioventricular and ventriculo-arterial discordance with intact septa and severe systemic right ventricular dysfunction (LAA indicates left atrial appendage; LA, left atrium; RV, right ventricle; LV, left ventricle). The patient had moderate tricuspid regurgitation and mild-to-moderate aortic regurgitation. An aneurysm was detected in the membranous ventricular septum (arrow) protruding into the anatomical left ventricular outflow tract (LVOT), with no interventricular short circuit recorded on color Doppler. The aneurysm cavity was partially occupied by a mass with an echogenicity consistent with thrombotic material. Although it has been speculated that membranous septum aneurysms may be an intracardiac source of emboli, this is the first case to our knowledge in which transesophageal echocardiography has detected a thrombosed aneurysm of the membranous interventricular septum.
Fig. 1.