Title

Statistical shape modeling reveals the link between right ventricular shape, hemodynamic force, and myocardial function in repaired Tetralogy of Fallot patients

Document Type

Journal Article

Publication Date

7-15-2022

Journal

American journal of physiology. Heart and circulatory physiology

DOI

10.1152/ajpheart.00228.2022

Keywords

Hemodynamic forces; Statistical shape modeling; Tetralogy of Fallot; Ventricular remodeling

Abstract

Repaired tetralogy of Fallot (rTOF) patients can develop chronic pulmonary insufficiency (PI) with right ventricular (RV) dilation, progressive RV dysfunction, and decreased exercise capacity. Pulmonary valve replacement (PVR) can help reduce the amount of PI and RV dilation, however optimal timing remains controversial; a better understanding of rTOF pathophysiology is of fundamental importance to inform clinical management of rTOF patients and optimal timing of PVR. In this study, we hypothesize a tight interplay between RV shape, intracardiac biomechanics and ventricular function in rTOF patients. To explore this hypothesis and derive quantitative measures, we combined statistical shape modeling with physics-based analysis of in-vivo 4D flow data in 36 rTOF patients. Our study demonstrated for the first time a correlation between regional RV shape variations, hemodynamic forces (HDF), and clinical dysfunction in rTOF patients. The main findings of this work include: i) general increase in RV size, due to both volume overload and physiologic growth, correlated with decrease in strain magnitude in the respective directions, and with increased QRS; ii) regional PI-induced remodeling accounted for ~10% of the shape variability of the population, and was associated with increased diastolic HDF along the diaphragm-to-RVOT direction, resulting in a net RV deformation along the same direction and decreased TAPSE; iii) three shape modes independently correlated with systolic HDF and exercise capacity. Identification of patients based on the shape variations described in this study could help identify those at risk for irreversible dysfunction and guide optimal timing of PVR.

Department

Pediatrics

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