Right Chambers Quantification in Clinical Practice: Echocardiography Compared with Cardiac Magnetic Resonance Imaging

Abstract

Hot Topics in Echocardiography 12mechanic activity which consists of inward, longitudinal and circumferential traction the systolic function is mainly determined by the longitudinal contraction which causes the shortening of the ventricle, with equal contribution from the interventricular septum and the free wall [ ]. Several factors contribute to RV global function, namely the preload, afterload and contractility. The preload is dependant on the volume status, the tricuspid valve gradient and the venous return from the vena cava. The afterload is determined by the resistance opposed by the pulmonary valve, the pulsatile flow reflected from the main pulmonary artery, the impedance of the proximal pulmonary artery and arterioles [ ]. Pulmonary vascular resistance may not, therefore, be used to assess RV total afterload, particularly in patients with pulmonary hypertension [ ]. Due to its thin free wall and high compliance, the RV can easily adapt to increased preload by dilatation, which can be well tolerated for a long time, although it eventually leads to RV failure. "y contrast, elevated afterload is poorly tolerated from an early stage, as the RV has little capacity for compensatory hypertrophy, which is quickly followed by increased stiffness and chamber dilatation [ ]. In clinical practice, changes in preload and afterload alter RV contraction. Other factors that may impair RV systolic function include abnormal variations of the heart rate, pharmacological agents, or ventricular interdependence [ ]. Ventricular interdependence refers to the fact that the shape, size and compliance of one ventricle may influence the shape, size or pressures in the other ventricle, an essential concept for understanding the pathophysiology of RV dysfunction [ ].