Skip to main page content
U.S. flag

An official website of the United States government

Dot gov

The .gov means it’s official.
Federal government websites often end in .gov or .mil. Before sharing sensitive information, make sure you’re on a federal government site.

Https

The site is secure.
The https:// ensures that you are connecting to the official website and that any information you provide is encrypted and transmitted securely.

Access keys NCBI Homepage MyNCBI Homepage Main Content Main Navigation
. 2022 Jan 21:8:806107.
doi: 10.3389/fcvm.2021.806107. eCollection 2021.

Right Ventricular Flow Vorticity Relationships With Biventricular Shape in Adult Tetralogy of Fallot

Ayah Elsayed  1 , Charlène A Mauger  1 , Edward Ferdian  1 , Kathleen Gilbert  2 , Miriam Scadeng  1 , Christopher J Occleshaw  3 , Boris S Lowe  3 , Andrew D McCulloch  4 , Jeffrey H Omens  4 , Sachin Govil  4 , Kuberan Pushparajah  5 , Alistair A Young  1   5
Affiliations

Right Ventricular Flow Vorticity Relationships With Biventricular Shape in Adult Tetralogy of Fallot

Ayah Elsayed et al. Front Cardiovasc Med. .

Abstract

Remodeling in adults with repaired tetralogy of Fallot (rToF) may occur due to chronic pulmonary regurgitation, but may also be related to altered flow patterns, including vortices. We aimed to correlate and quantify relationships between vorticity and ventricular shape derived from atlas-based analysis of biventricular shape. Adult rToF (n = 12) patients underwent 4D flow and cine MRI imaging. Vorticity in the RV was computed after noise reduction using a neural network. A biventricular shape atlas built from 95 rToF patients was used to derive principal component modes, which were associated with vorticity and pulmonary regurgitant volume (PRV) using univariate and multivariate linear regression. Univariate analysis showed that indexed PRV correlated with 3 modes (r = -0.55,-0.50, and 0.6, all p < 0.05) associated with RV dilatation and an increase in basal bulging, apical bulging and tricuspid annulus tilting with more severe regurgitation, as well as a smaller LV and paradoxical movement of the septum. RV outflow and inflow vorticity were also correlated with these modes. However, total vorticity over the whole RV was correlated with two different modes (r = -0.62,-0.69, both p < 0.05). Higher vorticity was associated with both RV and LV shape changes including longer ventricular length, a larger bulge beside the tricuspid valve, and distinct tricuspid tilting. RV flow vorticity was associated with changes in biventricular geometry, distinct from associations with PRV. Flow vorticity may provide additional mechanistic information in rToF remodeling. Both LV and RV shapes are important in rToF RV flow patterns.

Keywords: 4D flow; atlas; shape; tetralogy of Fallot; vorticity.

PubMed Disclaimer

Conflict of interest statement

This study received working expenses and in-kind support from Siemens Healthineers, Erlangen, Germany. The funder was not involved in the study design, collection, analysis, interpretation of data, the writing of this article or the decision to submit it for publication. AM and JHO are co-founders of and have an equity interest in Insilicomed, Inc., and serves on the scientific advisory board. Some of their research grants, including those acknowledged here, have been identified for conflict of interest management based on the overall scope of the project and its potential benefit to Insilicomed, Inc. The authors are required to disclose this relationship in publications acknowledging the grant support, however the research subject and findings reported here did not involve the company in any way and have no relationship whatsoever to the business activities or scientific interests of the company. The terms of this arrangement have been reviewed and approved by the University of California San Diego in accordance with its conflict of interest policies. The remaining authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest.

Figures

Figure 1
Figure 1
Diagrammatic representation of the methodology. 4D flow (A) was used for volumetric quantification of flow in the pulmonary and across the tricuspid valve (B) and velocity data was processed with the 4D flow neural network (C). Vorticity (D) was quantified and visualized with the vortex core and streamlines that demonstrate velocity within the spherical ROI was shown, and the dotted line represents the opening of the tricuspid valve. Cines (E) were used to extract EDV, ESV and SV (F). Cines were also used to build the models for the current population that were projected onto the atlas (G). Regression models (H) were used to compute shape variations associated with vorticity. The figure shows an overlapping of the diagrams of a normal biventricular model and the model generated to show the effect of vorticity.
Figure 2
Figure 2
Qualitative (left) and quantitative (right) evaluation of velocity and vorticity with and without the 4DFlownet. The panels show the 3 regions of interest where vorticity was captured (left: whole RV; middle: RVOT; right: tricuspid inflow in diastole. The network reduced noise making the vorticity structure more readily visualized. Right plots show mean vorticity calculated in the region of interest and mean velocity calculated at planes positioned in the RVOT, showing high correlation before and after 4DFlowNet.
Figure 3
Figure 3
Correlations of cardiac indices and vorticity with principal component analysis modes. PRVi, indexed pulmonary regurgitant volume; LVM, left ventricular mass; LVEDVi, indexed left ventricular end diastolic volume; LVSVi, indexed left ventricular stroke volume; LVESVi, indexed left ventricular end systolic volume; MVR, mass to volume ratio. Modes 9 and 6 Are the most correlated modes with aspects of cardiac metrics and vorticity. Bonferroni correction was done with all correlations.
Figure 4
Figure 4
Principal component shape variations associated with pulmonary regurgitant volume (top) and vorticity (bottom). The RV is shown in purple, left ventricle: green, the tricuspid valve: pink, the pulmonary valve: neon green, the aortic valve: yellow and mitral valve: blue. Each mode is shown in an anterior and posterior view with description below.
Figure 5
Figure 5
The effect of vorticity on the shape of the RV by a regression model. The spectrum of shapes is demonstrated in the line of shapes above to show the difference between a normal biventricular model (far right) and a model affected by high vorticity (far left). The larger overlapping shapes emphasize the differences. The RV enlargement affects the orientation of both the pulmonary and tricuspid valves. There is an architectural shift from the normal configuration to an enlarged bulging base. There is an evident effect on the LV as well showing the change in wall shape and position of the aortic and mitral valves due to the shift in the RV outflow tract configuration.
See this image and copyright information in PMC

References

    1. Geva T, Mulder B, Gauvreau K, Babu-Narayan SV, Wald RM, Hickey K, et al. . Preoperative predictors of death and sustained ventricular tachycardia after pulmonary valve replacement in patients with repaired tetralogy of fallot enrolled in the INDICATOR Cohort. Circulation. (2018) 138:2106–15. 10.1161/CIRCULATIONAHA.118.034740 - DOI - PubMed
    1. Gatzoulis MA, Till JA, Somerville J, Redington AN. Mechanoelectrical interaction in tetralogy of Fallot. QRS prolongation relates to right ventricular size and predicts malignant ventricular arrhythmias and sudden death. Circulation. (1995) 92:231–7. 10.1161/01.CIR.92.2.231 - DOI - PubMed
    1. Mansi T, Voigt I, Leonardi B, Pennec X, Durrleman S, Sermesant M, et al. . A statistical model for quantification and prediction of cardiac remodelling: application to tetralogy of Fallot. IEEE Trans Med Imaging. (2011) 30:1605–16. 10.1109/TMI.2011.2135375 - DOI - PubMed
    1. Zhang H, Wahle A, Johnson RK, Scholz TD, Sonka M. 4-D cardiac MR image analysis: left and right ventricular morphology and function. IEEE Trans Med Imaging. (2010) 29:350–64. 10.1109/TMI.2009.2030799 - DOI - PMC - PubMed
    1. Leonardi B, Taylor AM, Mansi T, Voigt I, Sermesant M, Pennec X, et al. . Computational modelling of the right ventricle in repaired tetralogy of Fallot: can it provide insight into patient treatment? Eur Heart J Cardiovasc Imaging. (2013) 14:381–6. 10.1093/ehjci/jes239 - DOI - PMC - PubMed