Imaging characteristics and associations in twisted atrioventricular connections on multidetector computed tomography angiography

AIM: To evaluate the imaging characteristics and associations in patients with twisted atrioventricular connections on multidetector computed tomography (CT) angiography. MATERIAL AND METHODS: We retrospectively reviewed 2605 CT angiography studies performed for suspected congenital heart diseases in our institution from January 2014 to December 2018. Twisted atrioventricular connections were diagnosed in 12 patients. Segmental sequential approach developed by Anderson et al was employed to characterize the complex congenital heart disease. Ventricular topology was also determined. CTA was also assessed to look for any associated intra- and extracardiac anomalies. RESULTS: Out of 12 patients with twisted atrioventricular connections, usual viscero-atrial arrangement was seen in nine patients, two patients had mirror-imaged viscero-atrial arrangement and one patient had mirror-imaged atrial arrangement. Right-sided heart was seen in four patients. Two patients had discordant atrioventricular connections, seven had concordant atrioventricular connections while three showed double-inlet right ventricle. Ventriculoarterial connections were concordant in two patients, discordant in one patient while nine patients had double-outlet right ventricle. Superior-inferior ventricular morphology with near-horizontal interventricular septum was seen in four patients. Left-sided aortic arch with normal branching pattern was observed in nine patients. No coronary anomaly was seen in any patient. Other associations included ventricular and atrial septal defects, pulmonic stenosis, hypoplasia/atresia of tricuspid valve, straddling of mitral valve, and duplicated superior caval veins. CONCLUSION: CT angiography is useful in diagnosis of twisted atrioventricular connections with accurate identification of viscero-atrial arrangement, atrioventricular and ventriculoarterial connections, and orientation and presence or absence of associated anomalies.