The Right Ventricle of the Endurance Athlete: The Relationship between Morphology and Deformation

Abstract

The aims of this study were to establish absolute ranges for right ventricular (RV) structural and functional parameters for endurance athletes and to establish any impact of body size. These data may help differentiate physiologic conditioning from arrhythmogenic RV cardiomyopathy. A prospective observational study design was used, and standard two-dimensional echocardiography was performed on 102 endurance athletes, providing RV structural indices. A two-dimensional strain (ε)technique was used to provide indices of RV ε and strain rate. The association of RV chamber size to body surface area (BSA) and functional indices was examined by simple ratio scaling as well as adoption of the general, nonlinear allometric model. The values for RV inflow, outflow, length, and diastolic area were greater than published "normal ranges" in 57%, 40%, 69%, and 59% of the population, respectively, while 28% of the population had RV outflow tract values greater than the proposed "major criteria" for arrhythmogenic RV cardiomyopathy. Simple ratio scaling for all RV dimensions to BSA did not produce size independence, whereas scaling for BSA allometrically did. Strain and strain rate values were consistent with published normal ranges, and there is no evidence to suggest that scaling is required. RV chamber dimensions are larger in endurance athletes than those described by "normal ranges" and frequently meet the major criteria for the diagnosis of arrhythmogenic RV cardiomyopathy. Functional assessment of RV ε may aid in this differential diagnosis. RV size is allometrically related to BSA and therefore scaling for population-specific b exponents is encouraged.