Changes in Right Ventricular Volume, Volume Load, and Function Measured with Cardiac Computed Tomography over the Entire Time Course of Tetralogy of Fallot

Abstract

Objective To characterize the changes in right ventricular (RV) volume, volume load, and function measured with cardiac computed tomography (CT) over the entire time course of tetralogy of Fallot (TOF). Materials and Methods In 374 patients with TOF, the ventricular volume, ventricular function, and RV volume load were measured with cardiac CT preoperatively (stage 1), after palliative operation (stage 2), after total surgical repair (stage 3), or after pulmonary valve replacement (PVR) (stage 4). The CT-measured variables were compared among the four stages. After total surgical repair, the postoperative duration (POD) and the CT-measured variables were correlated with each other. In addition, the demographic and CT-measured variables in the early postoperative groups were compared with those in the late postoperative and the preoperative group. Results Significantly different CT-based measures were found between stages 1 and 3 (indexed RV end-diastolic volume [EDV], 63.6 ± 15.2 mL/m 2 vs. 147.0 ± 38.5 mL/m 2 and indexed stroke volume (SV) difference, 7.7 ± 10.3 mL/m 2 vs. 32.2 ± 16.4 mL/m 2 ; p < 0.001), and between stages 2 and 3 (indexed RV EDV, 72.4 ± 19.7 mL/m 2 vs. 147.0 ± 38.5 mL/m 2 and indexed SV difference, 5.7 ± 13.1 mL/m 2 vs. 32.2 ± 16.4 mL/m 2 ; p < 0.001). After PVR, the effect of RV volume load (i.e., indexed SV difference) was reduced from 32.2 mL/m 2 to 1.7 mL/m 2 . Positive (0.2 to 0.8) or negative (−0.2 to −0.4) correlations were found among the CT-based measures except between the RV ejection fraction (EF) and the RV volume load parameters. With increasing POD, an early rapid increase was followed by a slow increase and a plateau in the indexed ventricular volumes and the RV volume load parameters. Compared with the preoperative data, larger ventricular volumes and lower EFs were observed in the early postoperative period. Conclusion Cardiac CT can be used to characterize RV volume, volume load, and function over the entire time course of TOF.

CT and MRI for Repaired Complex Adult Congenital Heart Diseases

“…Since repaired TOF patients with the aforementioned complications are often asymptomatic, CT and MRI, as additional noninvasive imaging methods, are frequently used not only for early detection of these complications, but also to determine the optimal timing of pulmonary valve replacement to avoid irreversible right ventricular dysfunction ( 13 14 ). According to the 2018 American College of Cardiology and American Heart Association guidelines for ACHD, MRI is regarded as the reference standard for evaluating right ventricular volume and function, quantification of pulmonary regurgitation, and detection of myocardial scarring ( 1 ).…”

“…Traditionally, cardiac CT has rarely been considered appropriate for ACHD in situations where cardiac MRI is contraindicated or non-diagnostic ( 15 ). However, cardiac CT acquired with optimized imaging protocols is increasingly being used in patients with repaired TOF ( 14 16 17 18 ).…”

“…However, this value may be misleading when regurgitation is substantial in valves other than the pulmonary valve. Therefore, it should be correctly expressed as volume load on the right ventricle rather than the pulmonary regurgitant fraction ( 14 ).…”

“…8B ) ( 29 ). A recent cross-sectional CT ventricular volumetry study demonstrated an early rapid increase (< 7 years after total surgical repair) followed by a slow increase and a plateau (up to approximately 34 years after total surgical repair) in the right ventricular volumes and right ventricular volume load parameters in 285 patients with repaired TOF ( 14 ).…”

CT quantification of ventricular volumetric parameters based on semiautomatic 3D threshold-based segmentation in porcine heart and children with tetralogy of Fallot: accuracy and feasibility

“…Recently, CT has allowed the quantification of left ventricular (LV) and RV volume. Several studies demonstrated good correlations between RV functional parameters obtained by CT and CMR10–13 with two-dimensional (2D) manual contouring-based segmentation in CMR and three-dimensional (3D) semiautomatic threshold-based segmentation in CT. CMR 2D manual contouring is relatively accurate, but may take more time than CT 3D semiautomatic threshold-based segmentation. Papillary muscles and trabeculations are included in calculating ventricular volume in 2D CMR segmentation, while they are excluded in CT 3D semiautomatic threshold-based segmentation.…”