The effects of positioning (horizontal and Trendelenburg) and positive end-expiratory pressure (PEEP) on echocardiographic indices of diastolic function including tissue Doppler peak early (e’) and atrial (a’) diastolic velocities of the mitral valve annuli (A and B), pulsed Doppler peak early (E) and atrial (A) diastolic transmitral flow (C) and E deceleration time (D). In addition, the effects of positioning and PEEP on the composite ratios E/A, E/e’, and e’/a’ are shown (D–F). ANOVA, P_PEEP = P values of PEEP, ANOVA; Average = averaged from the septal and lateral mitral valve annuli; P_positioning = P values of positioning.