title: Effective arterial elastance as an index of pulmonary vascular load.
abstract: The aim of this study was to test whether the simple ratio of right ventricular (RV) end-systolic pressure (Pes) to stroke volume (SV), known as the effective arterial elastance (Ea), provides a valid assessment of pulmonary arterial load in case of pulmonary embolism- or endotoxin-induced pulmonary hypertension. Ventricular pressure-volume (PV) data (obtained with conductance catheters) and invasive pulmonary arterial pressure and flow waveforms were simultaneously recorded in two groups of six pure Pietran pigs, submitted either to pulmonary embolism (group A) or endotoxic shock (group B). Measurements were obtained at baseline and each 30 min after injection of autologous blood clots (0.3 g/kg) in the superior vena cava in group A and after endotoxin infusion in group B. Two methods of calculation of pulmonary arterial load were compared. On one hand, Ea provided by using three-element windkessel model (WK) of the pulmonary arterial system [Ea(WK)] was referred to as standard computation. On the other hand, similar to the systemic circulation, Ea was assessed as the ratio of RV Pes to SV [Ea(PV) = Pes/SV]. In both groups, although the correlation between Ea(PV) and Ea(WK) was excellent over a broad range of altered conditions, Ea(PV) systematically overestimated Ea(WK). This offset disappeared when left atrial pressure (Pla) was incorporated into Ea [Ea * (PV) = (Pes - Pla)/SV]. Thus Ea * (PV), defined as the ratio of RV Pes minus Pla to SV, provides a convenient, useful, and simple method to assess the pulmonary arterial load and its impact on the RV function.
authors.affiliation: Hemodynamics Research Laboratory (HemoLiege), University Hospital of Liege, Liege, Belgium. ph.morimont@chu.ulg.ac.be
authors.forename: Philippe
authors.initials: P
authors.lastname: Morimont
authors.forename: Bernard
authors.initials: B
authors.lastname: Lambermont
authors.forename: Alexandre
authors.initials: A
authors.lastname: Ghuysen
authors.forename: Paul
authors.initials: P
authors.lastname: Gerard
authors.forename: Philippe
authors.initials: P
authors.lastname: Kolh
authors.forename: Patrizio
authors.initials: P
authors.lastname: Lancellotti
authors.forename: Vincent
authors.initials: V
authors.lastname: Tchana-Sato
authors.forename: Thomas
authors.initials: T
authors.lastname: Desaive
authors.forename: Vincent
authors.initials: V
authors.lastname: D'Orio
mesh_terms: D000818:Animals; D016279:Atrial Function, Left; D001794:Blood Pressure; D004195:Disease Models, Animal; D004548:Elasticity; D005260:Female; D006976:Hypertension, Pulmonary / Q000209:etiology / Q000503:physiopathology*; D008070:Lipopolysaccharides; D008297:Male; D008955:Models, Cardiovascular; D011651:Pulmonary Artery / Q000503:physiopathology*; D011652:Pulmonary Circulation; D011655:Pulmonary Embolism / Q000150:complications* / Q000503:physiopathology; D015203:Reproducibility of Results; D012772:Shock, Septic / Q000139:chemically induced / Q000150:complications* / Q000503:physiopathology; D013318:Stroke Volume; D013552:Swine; D013599:Systole; D013997:Time Factors; D016278:Ventricular Function, Right; D017725:Ventricular Pressure
chemical_list: D008070:Lipopolysaccharides