A quantitative assessment of aorta root rotation in patients with tetralogy of Fallot evaluated by MSCT

Soha Romeih,Mohamed Hashem,Mohamed Gibreel,Mohamed Elzoghby,Wesam El Mozy,Mohamed Abdelfattah,Alaa Kaoud,Mahmoud Shaaban

doi:10.1038/s41598-021-93814-4

Soha Romeih, Mohamed Hashem + Show 6 more

Open Access

https://doi.org/10.1038/s41598-021-93814-4

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Abstract

Lack of conal rotation and conal malseptation is a characteristic anatomical feature for TOF which lead to dextroposed position of aorta and significant RVOT narrowing. The quantitative assessment of these anatomical features using modern cardiac imaging modality has been rarely discussed in the literature. All TOF scanned had in our center from 2013 till 2019 were included. The angle of aortic root rotation was recorded by measuring the angle between a line connecting the midpoint of the non-coronary sinus to the anterior commissure and another line along the interatrial septum. Rotation angles were correlated with proximal main pulmonary artery (MPA) size indexed to BSA. 287 TOF patients were included, 258 patients (91%) had TOF with pulmonary stenosis (TOF-PS) including 138 male (54%), median age 2 years (2 months–40 years), and 29 patients (9%) had TOF with pulmonary atresia (TOF-PA) including 17 male (59%), median age 5 years (1 m-33 years). The whole cases demonstrated clockwise rotation of the aortic root. The mean rotation angle in TOF-PS group was 52.6 ± 20.9° and in TOF-PA group was 64.9 ± 13.9°. Proximal MPA diameter was 11.1 ± 5.9 mm/m2. There was a significant negative correlation between aortic root rotation angle and proximal MPA diameter (r = − 0.262, P = 0.000). The rotation angle of aortic root was significantly higher in TOF-PA compared to TOF-PS (64.9 ± 13.9° vs. 52.6 ± 20.9°, P = 0.001, respectively). MSCT provide a quantitative measurement methodology of conal malseptation and its effect in TOF patients. There is a clockwise rotation angle of the aortic root in TOF patients that correlates negatively with proximal MPA size. TOF-PA have a larger rotation angle of aortic root.

Highlights

Tetralogy of Fallot (TOF) is the most common cyanotic congenital heart disease (CHD) and constitutes 3.5% of all CHD1
TOF is characterized by the lack of conal rotation and conal malseptation which is anatomically demonstrated by the anterior deviation of the conal septum[2,3]
The included TOF patients were either (1) TOF with pulmonary valve stenosis (TOF-PS), who have a forward flow from the RV through a stenotic and narrowed pulmonary valve to the pulmonary artery, (2) TOF with pulmonary atresia (TOF-PA), who have no forward flow from the RV to pulmonary arteries, the pulmonary blood supply depends mainly on patent ductus arteriosus or collaterals

Summary

Introduction

Tetralogy of Fallot (TOF) is the most common cyanotic congenital heart disease (CHD) and constitutes 3.5% of all CHD1. Kramer et al first suggested that “the outflow tract of both ventricles is the region where the conus joins the truncus and that resorption and differential growth are responsible for the reduction of the conoventricular flange, making the conus shift from the extreme right toward the midline of the septum where it comes into alignment with the muscular portion of the interventricular septum”[2]. The lack of this normal conal rotation brings the aorta to a dextro-posterior position during normal embryogenesis[4]. The clockwise angle rotation of the aortic root could be a potential indicator for the severity of conal malseptation and the RVOT maldevelopment

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