Understanding right ventricular dyssynchrony: Its myriad determinants and clinical relevance

dyssynchrony, loading, right ventricleIt is a well-worn cliché that the right ventricle (RV) is forgotten or neglected, yet it is already the subject of a huge scientific literature.It is clear that pulmonary arterial (PA) pressure and RV function are major predictors of morbidity and mortality in many cardiovascular diseases, but improving RV function as a therapeutic target remains elusive.It is likely that changes in global and regional function are more often consequences of disease than primary causative factors; therefore, understanding their pathophysiological mechanisms is a prerequisite to using indicators of RV function as a guide to clinical decisions.Myocardial segmental deformation as a function of time is related to the local balance of its contractile force and counteracting loading forces, consisting of cavity pressure (modulated by local shape), neighbouring force development (potentially with a different onset of activation) and tissue elasticity (Bijnens et al., 2007).This leads to a more-or-less straightforward interpretation in the normal left ventricle (LV) with its ellipsoid shape and more homogeneous conduction system, but in the RV interpretation remains challenging.Firstly, the conduction system in the RV is not as homogeneously distributed over the endocardium as in the LV.