Influence of Respiratory Variation. Transvalvular flow variation (QTC shown in Panels A1-A4 and QM shown in Panels B1-B4) during a cycle of respiration (expiration (Exp.) and inspiration (Insp.) are marked). The red lines trace the respiratory variation. Pulmonary vasculature volume is shown in Panels C1-C4. Pulmonary blood volume increases with LVDD, with IR-type LVDD having the lowest increase and PN-type LVDD having the highest increase.