Athletic shapeshifting of the right ventricle: 3D echocardiography-derived global and regional shape analysis in elite athletes
Authors: Fabian A , Szijarto A , Hatvani J , Magyar B , Lakatos B K , Ladanyi Z S , Ferencz A , Lundegaard S , Tokodi M , Zamodics M , Sydo N , Vago H , Kiss O , Merkely B , Kovacs A 
Published: January 2025

Abstract
Intense physical activity poses marked hemodynamic strain on the right ventricle (RV), as during exercise, RV is subjected to a proportionally higher pressure and volume overload than its left counterpart. While the morphological changes of the left ventricle can be characterized using pre-defined reference shapes (cone and sphere), the complex structure of the RV cannot be captured similarly. Therefore, the exercise-induced changes in the RV's global and regional shape have not been directly investigated.
Our aim was to develop a 3D echocardiography (3DE)-based method to quantify the global and regional shape metrics of the RV in a large cohort of elite athletes.
Elite athletes (n=138) and healthy, sedentary volunteers (n=104) were enrolled and underwent 3DE to measure RV volumes and ejection fraction (EF). 3D RV endocardial mesh models were reconstructed at end-diastole and end-systole to quantify regional curvature indices along 5 clinically relevant parts of the RV (apex, septum, free-wall, outflow tract, and inflow tract). Zero curvature depicts a flat surface, whereas a more positive or negative curvature represents a more convex or concave surface, respectively. Regarding the RV’s global shape, hemi-conicity and hemi-sphericity indices were introduced (Figure 1). First, the longitudinal height of the 3D RV mesh was defined. To calculate hemi-sphericity index, a hemisphere (with a radius that is half the height of the RV mesh) was created. Then, the volume of this hemisphere and the volume of the RV mesh were compared (a higher volume ratio depicts a more spherical shape). To calculate hemi-conicity index, a half-cone (whose height equals the RV’s height and volume equals the RV mesh’s volume) was defined. Then, the angle at the top of the half-cone was evaluated (a more acute angle describes a more conical shape).
As expected, athletes had higher RV end-diastolic (EDV; 165±36 vs. 146±44 ml, p&lt;0.001) and end-systolic volumes (ESV; 75±22 vs. 65±23, p&lt;0.005), whereas RV EF did not differ in the two groups. Regional curvature analysis showed that in athletes, the septum of the RV was significantly flatter (-0.4±9 vs. 6.7±7.7, p&lt;0.001), along with the RV free-wall curvature index that also depicted a significantly flatter shape (57.9±8.3 vs. 61.2±7.7, p&lt;0.001) compared to controls. The global shape assessment revealed that the RV of the athlete’s heart had a more conical shape, as the hemi-sphericity volume ratio was significantly lower (0.79±0.17 vs. 1.19±0.40, p&lt;0.001), and the hemi-conicity angle exhibited a more acute angle (63.8± 5.7 vs. 74.1±9.1, p&lt;0.001) both pointing towards a conical remodeling.
The assessment of 3D echocardiography-derived regional and global shape metrics revealed a different, more conical geometry in the athletes’ RV. Our novel method may enable a more precise quantification of the RV's unique, exercise-induced geometrical remodeling.
Figure 1