Pulmonary circulatory – right ventricular uncoupling: New insights into pulmonary hypertension pathophysiology

The pulmonary circulatory – right ventricular uncoupling is a key pathophysiological feature of pulmonary hypertension. Uncoupling develops when the ventricular contractility is not matched to its afterload due to a discordant response of the RV to increased afterload, or to an impaired right ventricular function. In this chapter we reported the methods which were developed to quantify the right ventricular –pulmonary artery (RV-PA) coupling in patients with PH and in experimental models of PH. The RV pressure-volume loop analysis are the gold standard to quantify RV-PA coupling metrics but more simple and less invasive methods were developed. We also reported how the RV-PA coupling metrics may be used to improve the phenotyping of patients and experimental models with PH. RV-PA coupling was also used to quantify the pharmacological effects of treatments in animal models with PH and to improve the understanding of the pathophysiological differences in different PH types. In recent studies, RV-PA coupling quantification with imaging methods showed interesting application to prognosis stratification of patients with PH.