Comparison of Model Ventricular Pressure-Volume Loops. Comparing modeled ventricular function curves of normal physiology (C, solid black line) with LVDD due to impaired LV wall relaxation (IR, dotted red line), increased LV wall stiffness (R, dashed blue line), and combined impaired relaxation and increased wall stiffness (PN, dash-dot magenta line). Panels A and B show RV and LV chamber pressures and volumes, respectively. All simulations here are with normal systolic contractility. LVDD types: IR (impaired relaxation); R (resistive) and PN (pseudo-normal) patterns (discussed later).