Figure 13
Left Ventricular Performance Variation in Respiratory Cycle. An in-depth look at respiratory variation in left ventricular performance with tamponade. Model results are given for the control case and the severe tamponade case (1000 ml effusion) in the first and second columns, respectively. One cardiac cycle displaying PLV and PAO during expiration (red), inspiration (blue), and fixed mean PPL (black) are overlaid with alignment of aortic valve closure (Panels A-B). Panels C-D show left ventricular volume, and Panels E-F show septal movement. In the control case, aortic valve opening (AO) and pre-ejection period (PEP) varies with respiration; specifically, during inspiration, PEP is slowed, delaying AO, and reducing the ejection time (Panel A). With tamponade, PEP on the whole is slowed compared to control, and the respiratory variation is exaggerated (Panel B). The elongated PEP is also evident in VLV (Panel D). During the PEP, the septum hangs in the neutral position, delaying the leftward thrust which can only start at AO (Panel F). (AO = aortic valve opening, AC = aortic valve closure, MO = mitral valve opening, MC = mitral valve closure)