The Right Ventricle: Unforgettable With Imaging.

T he right ventricle has been described as the “forgotten chamber,” and despite better awareness of its importance, current heart failure (HF) guidelines have taken little cognizance of the right ventricle. In part, this reflects the limitations of the evidence regarding the determinants of right ventricular (RV) dysfunction and its relation to outcomes in HF. This special issue of iJACC seeks to redress this in some part through a collection of focused reports. RV dysfunction has an important and independent effect on cardiac mortality in nonischemic cardiomyopathy (1). Although RV dysfunction is strongly associated with left ventricular (LV) function, increased afterload from pulmonary vascular dysfunction, and systolic blood pressure, RV ejection fraction by cardiac magnetic resonance imaging is also a strong independent predictor, independent of age, LV ejection fraction, and other likely confounders. RV function is sensitive to increased afterload, and this is important in HF, in which increased left atrial (LA) pressure is conducted to the right ventricle through increased pulmonary pressures. Guazzi et al. (2) sought to stratify clinical phenotypes and outcomes on the basis of RV contractile function and its coupling with the pulmonary circulation in 387 patients with HF with preserved ejection fraction (HFpEF). Tertiles of tricuspid annular plane systolic excursion/pulmonary artery systolic pressure ratio (<0.35, >0.57, and levels in between) were associated with natriuretic peptides, systemic and pulmonary hemodynamic status, exercise aerobic capacity,