S-nitroso human serum albumin attenuates pulmonary hypertension, improves right ventricular-arterial coupling, and reduces oxidative stress in a chronic right ventricle volume overload model.

This study examined the acute effect of intravenous S-nitroso human serum albumin (S-NO-HSA) infusion on overall hemodynamics and oxidative stress in a chronic left-to-right shunt-induced pulmonary arterial hypertension model with right ventricle (RV) failure. An aortocaval fistula (pulmonary-to-systemic blood flow ratio [Qp/Qs] > 2.0) was surgically created in 50 male Wistar rats. After 10 weeks, they were randomly treated with S-NO-HSA (n = 20) or human serum albumin (HSA; n = 25) infusion (0.5 µmol/kg/h) for 60 minutes. A sham group (n = 10) received S-NO-HSA. RV contractility, RV-vascular coupling, and ventricular interdependence were assessed in vivo at different pre-loads by biventricular conductance catheters. Heart and lung biopsy specimens were obtained for determination of high-energy phosphates, oxidative stress (oxidized glutathione/reduced glutathione), and endothelial nitric oxide synthase protein expression. S-NO-HSA, compared with HSA infusion, reduced RV afterload expressed by effective pulmonary arterial elastance (Ea; 0.49 ± 0.3 vs 1.2 ± 0.2 mm Hg/ml; p = 0.0005) and improved RV diastolic function (slope of end-diastolic pressure-volume relationship) as well as contractility indicated by slope of end-systolic pressure-volume relationship (Ees). Therefore an increase in efficiency of ventricular-vascular coupling (Ees/Ea) occurred after S-NO-HSA (0.35 ± 0.17 to 0.94 ± 0.21; p = 0.005), but not HSA infusion, leading to positive effect on ventricular interdependence with increased left ventricular stroke volume (56% ± 4% vs 19% ± 5%; p = 0.0013). S-NO-HSA, compared with HSA, treatment improved adenosine 5'-triphosphate (13.9 ± 1.1 vs 7.0 ± 1.8 µmol/g protein) and phosphocreatine (5.9 ± 3.3 vs 1.9 ± 0.6 µmol/g protein; p = 0.01) RV content and decreased the tissue oxidized glutathione/reduced glutathione ratio (p = 0.001). S-NO-HSA reduces pulmonary hypertension and improves RV systolic and diastolic function and RV-arterial coupling, with a positive effect on ventricular interdependence by increasing energetic reserve and reducing oxidative stress.

Rungatscher A ，Hallström S ，Linardi D ，Milani E ，Gasser H ，Podesser BK ，Scarabelli TM ，Luciani GB ，Faggian G ... -  《-》

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.

Guihaire J ，Haddad F ，Boulate D ，Decante B ，Denault AY ，Wu J ，Hervé P ，Humbert M ，Dartevelle P ，Verhoye JP ，Mercier O ，Fadel E ... -  《-》

Chronic overcirculation-induced pulmonary arterial hypertension in aorto-caval shunt.

Pulmonary arterial hypertension is a common complication of congenital heart defects with left-to-right shunts. Current preclinical models do not reproduce clinical characteristics of shunt-related pulmonary hypertension. Aorto-caval shunt was firstly described as a model of right ventricle volume overload. The pathophysiology and the possible determination of pulmonary arterial hypertension of different periods of shunt exposure are still undefined. A method to create standardized, reproducible aorto-caval shunt was developed in growing rats (260±40 g). Three groups of animals were considered: shunt exposure for 10 weeks, shunt exposure for 20 weeks and control (sham laparotomy). Echocardiography and magnetic resonance revealed increased right ventricular end diastolic area in shunt at 10 weeks compared to control. Hemodynamic analysis demonstrated increased right ventricular afterload and increased effective pulmonary arterial elastance (Ea) in shunt at 20 weeks compared to control (1.29±0.20 vs. 0.14±0.06 mmHg/μl, p=0.004). At the same time point, the maximal slope of end-systolic pressure-volume relationship (Ees) decreased (0.5±0.2 mmHg/ml vs. 1.2±0.3, p<0.001). Consequently, right ventricular-arterial coupling was markedly deteriorated with a ≈50% decrease in the ratio of end-systolic to pulmonary artery elastance (Ees/Ea). Finally, left ventricular preload diminished (≈30% decrease in left ventricular end-diastolic volume). Histology demonstrated medial hypertrophy and small artery luminal narrowing. Chronic exposure to aorto-caval shunt is a reliable model to produce right ventricular volume overload and secondary pulmonary arterial hypertension. This model could be an alternative with low mortality and high reproducibility for investigators on the underlying mechanisms of shunt-related pulmonary hypertension.

Rungatscher A ，Linardi D ，Milani E ，Ucci G ，Nicolato E ，Merigo F ，Salvetti B ，Mazzucco A ，Luciani GB ，Faggian G ... -  《-》

Reserve of Right Ventricular-Arterial Coupling in the Setting of Chronic Overload.

Tello K ，Dalmer A ，Axmann J ，Vanderpool R ，Ghofrani HA ，Naeije R ，Roller F ，Seeger W ，Sommer N ，Wilhelm J ，Gall H ，Richter MJ ... -  《-》

Levosimendan improves right ventriculovascular coupling in a porcine model of right ventricular dysfunction.

Missant C ，Rex S ，Segers P ，Wouters PF ... -  《CRITICAL CARE MEDICINE》