Clarifying the Cardiovascular Morphology and Associated Abnormalities in Patients with Double Inlet Right Ventricle Using Multidetector CT Angiography.

We sought to evaluate the intracardiac morphology and associated cardiovascular anomalies in patients with double inlet right ventricle (DIRV) on multidetector CT angiography. A retrospective search of our departmental database was conducted from January 2014 to January 2023 to identify patients with a diagnosis of DIRV on CT angiography. The intracardiac anatomy and associated cardiovascular abnormalities were systematically evaluated. Patients with a common atrioventricular valve were excluded. DIRV was diagnosed in 41 patients (36 males, 5 females; mean age at imaging: 7.4 years [range: 4 months-30 years]). Mirror-imaged viscero-atrial arrangement was observed in 12/41 (29.3%) while right isomerism and left isomerism were seen in 6/41 (14.6%) and 2/41 (4.9%) patients respectively. Hypoplastic left ventricular cavity was seen in 39/41 (95.1%) patients. AV valve straddling was observed in 40/41 (97.6%) patients. Atrial septal defect was seen in 28/41 (68.3%) patients. All (100%) patients had presence of ventricular septal defect. Twisted atrioventricular connections were seen in 4/41 (9.8%) patients. The most common ventriculo-arterial morphology was presence of double outlet right ventricle (DORV) seen in 25/41 (61%) patients. Some degree of pulmonary outflow obstruction was seen in 24/41 (58.5%) patients. Systemic venous anomalies, pulmonary venous anomalies and coronary artery anomalies were observed in 13/41 (31.7%), 6/41 (14.6%) and 8/41 (19.5%) patients. DIRV is a type of single ventricle congenital heart disease associated with an array of cardiovascular abnormalities, most commonly DORV and pulmonary outflow tract obstruction. The knowledge of associated anomalies is imperative for preoperative planning. CT angiography allows for detailed anatomical evaluation of DIRV and associated cardiovascular anomalies which may positively impact surgical management in these patients.