Assessment of Right Ventricular‐Pulmonary Arterial Coupling in Heart Failure With Preserved Ejection Fraction Using Three‐Dimensional Speckle‐Tracking Echocardiography and Pulmonary Artery Stiffness

A novel index, termed the right ventricle (RV)‐pulmonary artery (PA) index, was established by integrating the longitudinal strain of the right ventricular free wall (RVFWLS) and the right ventricular ejection fraction (RVEF), both evaluated using three‐dimensional speckle‐tracking echocardiography (3D‐STE), with the stiffness of the pulmonary artery (PAS). This approach aims to enhance our understanding of the underlying mechanisms associated with heart failure with preserved ejection fraction (HFpEF).