Figure 4
From: Clinical review: Positive end-expiratory pressure and cardiac output
Effect of positive end-expiratory pressure (PEEP) on left ventricular (LV) filling. Any decrease in systemic venous return and, thus, right ventricular (RV) inflow must result in decreased pulmonary venous return and inflow to the left ventricle because the two ventricles pump in series. In addition to this passive coupling of the right and left ventricle, PEEP may have more direct mechanical effects on LV filling as the two ventricles share common fiber bundles, a common interventricular septum, coexist within the same pericardial space, and are surrounded by a fixed cardiac fossa volume. This parallel interaction between the ventricles, whereby the function of one ventricle influences the function of the other, is called ventricular interdependence. Classically, ventricular interdependence is thought to occur as increases in RV volume decrease LV diastolic compliance, LV preload, and LV output (acute cor pulmonale). EDP, end-diastolic pressure; EDV end-diastolic volume. Inserts adapted from [69], with permission.