An Unusual Case of Congenitally Corrected Transposition of the Great Arteries in the Elderly
A 56-year-old man1–4 with a history of mild dyspnea for several years and without cardiovascular risk factors was referred to our institution for coronary angiography. Before he was admitted to the hospital, a transthoracic 2-dimensional echocardiogram (TTE) was performed. The TTE was not diagnostic enough because of a suboptimal acoustic window and a technetium-99m single photon emission computed tomography pharmacological (dipyridamole) stress test that showed a mild, reversible left ventricular septal perfusion defect. On admission to our institution, the patient was asymptomatic and had no signs of heart failure on physical examination; however, a mild systolic (grade 2) murmur was heard on cardiac auscultation.
An ECG at rest showed a sinus rhythm with normal PR interval and complete left bundle-branch block that had been previously diagnosed (Figure 1). The patient underwent coronary artery angiography, which showed a common origin of both the left and right coronary arteries from right coronary sinus (Figure 2 and Movie I) without coronary artery stenosis. Left-sided ventriculography showed a dilated and morphologically hypertrophic right ventricle (triangular-shaped structure with inlet, trabecular, and outlet components) with normal systolic function and mild regurgitation of the atrioventricular valve (Figure 3 and Movie II). A congenitally corrected transposition of the great arteries (L-TGA) was suspected. TTE confirmed the diagnosis, showing a normal visceral situs, levocardia, and atrial situs but abnormal apical displacement of the left atrioventricular valve (Figure 4). Moreover, the left ventricle showed the moderator band crossing the apex of the chamber. Diagnosis was completed with a transesophageal echocardiogram that clearly showed a right ventricle–shaped left ventricle with a mildly regurgitant tricuspid atrioventricular valve that had an abnormal apical displacement (Figure 5 and Movie III) and abnormal atrioventricular and ventriculoarterial connections with aorta arising from right ventricular outflow tract (Figure 6). A mitropulmonary continuity was also detected with transesophageal echocardiogram (Figure 7 and Movies IV and V). The 2 great arteries did not loop around each other but rather were parallel (Figure 7), with the aorta placed anteriorly left and pulmonary artery placed posteriorly right (Figure 8). No associated congenital cardiac defects were identified. The patient was discharged from the hospital with medical therapy and referred for clinical follow-up.
L-TGA is a rare form of congenital heart disease, accounting for <1% of all congenital heart defects. It is characterized by an atrioventricular and ventriculoarterial discordance. It is very unusual to find L-TGA without any other associated cardiac anomalies.
The online-only Data Supplement, which contains Movies I through V, is available with this article at http://circ.ahajournals.org/cgi/content/full/117/ 24/e485/DC1.
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