Figure 5.

Chamber-specific downregulation of β₁-adrenergic receptors in failing right ventricles (RVs) from patients with pulmonary arterial hypertension (PAH). Shown are β₁- and β₂-adrenergic receptor densities in crude myocardial membranes prepared from ventricular free wall 1-g tissue aliquots of nonfailing organ donor controls with normal left ventricular ejection fractions whose hearts could be placed for transplantation, idiopathic dilated cardiomyopathy with biventricular failure hearts removed from transplant recipients, and hearts removed from heart-lung transplant recipients who had PAH and from primary or idiopathic pulmonary hypertension (PPH). Adapted from data in Bristow et al.²⁵ PPH: patients with PAH; LV: left ventricle.