title: Non-invasive indices of right ventricular function are markers of ventricular-arterial coupling rather than ventricular contractility: insights from a porcine model of chronic pressure overload.
abstract: OBJECTIVE
  To investigate the physiological correlates of indices of RV function in a model of chronic pressure overload.
  
  
  RESULTS
  Chronic pulmonary hypertension (PH) was induced in piglets by ligation of the left pulmonary artery (PA) followed by weekly embolization of right lower lobe arteries for 5 weeks (the PH group, n = 11). These animals were compared with sham-operated animals (controls, n = 6). At 6 weeks, a subgroup of five PH pigs underwent surgical reperfusion of the left lung and four others were followed until 12 weeks without treatment. Right ventricular function was assessed using echocardiography and conductance catheter measurements. At 6 weeks, mean PA pressure was higher in PH group compared with controls (35 ± 9 vs. 14 ± 2 mmHg, P < 0.01). Although RV elastance (Ees) increased at 6 weeks in the PH group (0.55 ± 0.09 vs. 0.38 ± 0.05 mmHg/mL, P < 0.001), ventricular-arterial coupling measured by the ratio of Ees on PA elastance (Ea) was decreased (0.68 ± 0.17 vs. 1.18 ± 0.18, P < 0.001). There was a strong direct relationship between Ees/Ea and indices of RV function, while relationship between Ees and indices of RV function was moderate. Changes in indices of RV function with time and after left lung reperfusion were associated with changes in Ees/Ea.
  
  
  CONCLUSIONS
  Usual indices of RV function are associated with ventricular-arterial coupling rather than with ventricular contractility in a model of chronic pressure overload.
authors.affiliation: Laboratory of Surgical Research and Inserm U999, University of Paris Sud, University of Paris XI, Marie Lannelongue Hospital, 133 avenue de la Résistance, Le Plessis Robinson, France.
authors.forename: Julien
authors.initials: J
authors.lastname: Guihaire
authors.forename: Francois
authors.initials: F
authors.lastname: Haddad
authors.forename: David
authors.initials: D
authors.lastname: Boulate
authors.forename: Benoît
authors.initials: B
authors.lastname: Decante
authors.forename: Andre Y
authors.initials: AY
authors.lastname: Denault
authors.forename: Joseph
authors.initials: J
authors.lastname: Wu
authors.forename: Philippe
authors.initials: P
authors.lastname: Hervé
authors.forename: Marc
authors.initials: M
authors.lastname: Humbert
authors.forename: Philippe
authors.initials: P
authors.lastname: Dartevelle
authors.forename: Jean-Philippe
authors.initials: JP
authors.lastname: Verhoye
authors.forename: Olaf
authors.initials: O
authors.lastname: Mercier
authors.forename: Elie
authors.initials: E
authors.lastname: Fadel
mesh_terms: D000704:Analysis of Variance; D000818:Animals; D002908:Chronic Disease; D004195:Disease Models, Animal; D006439:Hemodynamics / Q000502:physiology; D006976:Hypertension, Pulmonary / Q000150:complications* / Q000503:physiopathology*; D009200:Myocardial Contraction / Q000502:physiology*; D015425:Myocardial Reperfusion / Q000379:methods; D015588:Observer Variation; D011652:Pulmonary Circulation / Q000502:physiology; D011669:Pulmonary Wedge Pressure; D011897:Random Allocation; D012016:Reference Values; D018570:Risk Assessment; D012680:Sensitivity and Specificity; D013318:Stroke Volume / Q000502:physiology*; D034421:Sus scrofa; D013552:Swine; D014655:Vascular Resistance / Q000502:physiology*; D018497:Ventricular Dysfunction, Right / Q000150:complications / Q000503:physiopathology* / Q000601:surgery; D016278:Ventricular Function, Right / Q000502:physiology; D020257:Ventricular Remodeling
keywords: Animal model; Echocardiography; Pulmonary hypertension; Right ventricle; Ventricular function; Ventricular–arterial coupling