scholarly journals Metabolic Response to Stress by the Immature Right Ventricle Exposed to Chronic Pressure Overload

2019 ◽  
Vol 8 (17) ◽  
Author(s):  
Masaki Kajimoto ◽  
Muhammad Nuri ◽  
Nancy G. Isern ◽  
Isabelle Robillard‐Frayne ◽  
Christine Des Rosiers ◽  
...  
1983 ◽  
Vol 28 (4) ◽  
pp. 268-273 ◽  
Author(s):  
Carta Atkinson ◽  
John H. Milsum

2019 ◽  
Vol 40 (Supplement_1) ◽  
Author(s):  
E Majos ◽  
A Kraska ◽  
I Kowalik ◽  
E Smolis-Bak ◽  
H Szwed ◽  
...  

Abstract Background Assessment of the right ventricle (RV) in heart failure (HF) is challenging and requires applicable methods and parameters. Atrial fibrillation (AF) is a common and clinically significant arrhythmia in 30–50% of HF patients. Assessment of the RV function in patients with AF is problematic. Still little is known about RV function in HF and AF patients. The aim of the study was to assess RV function in HF with focus on AF patients. Methods Patients with HF of ischemic etiology, NYHA II-III, LVEF ≤40%, with AF and sinus rhythm (SR), underwent two- and three- dimensional echocardiography (2DE and 3DE) for assessment of the RV with use of multiple parameters. The RV was examined for: linear dimensions, end-diastolic and end-systolic areas adjusted to body surface area (RV EDA and RV ESA/BSA) and end-diastolic and end-systolic volumes adjusted to lean body mass (RV EDV and RV ESV/LBM) to reflect volume overload and in terms of right ventricular pressure (RVSP) as an index of pressure overload. RV systolic function was assessed with 2DE: tricuspid annular plane systolic excursion (TAPSE), right ventricular fractional area change (RV FAC), tricuspid lateral annular systolic velocity (s') and 3DE parameters: right ventricular ejection fraction (RVEF) and free wall right ventricular longitudinal strain (FW RVLS). Also, TAPSE/RVSP parameter was included. Results The study included 126 patients: 94 with AF and 32 with SR. Within the AF group 28 patients were treated medically, 41 had RV pacing (pacemaker or an implantable cardioverter-defibrillator, ICD) and 25 had cardiac resynchronisation therapy (CRT). In comparison with SR group AF patients had: larger RV inflow tract dimension (4.49±0.85 vs. 3.95±0.72 cm; p=0.0017), RV EDA/BSA (12.7±3.9 vs. 11.1±3.0 cm2/m2; p=0.0358) and RV ESA/BSA (8.0±3.0 vs. 6.7±2.4 cm2/m2; p=0.0226). Similarly, patients with AF had greater RV volumes in 3DE than patients with SR: RV EDV/LBM (1.82±0.60 vs. 1.61±0.38ml/kg, p=0.0267) and RV ESV/LBM (1.11±0.40 ml/kg vs. 0.81±0.28, p<0,0001). Also, in patients with AF right ventricular systolic pressure (RVSP) was higher (40.8±10.2 vs. 34.0±8.1 mmHg, p=0,0010). No differences in TAPSE and RVFAC were found but the relation TAPSE/RVSP was higher in AF than in SR group (0.51±0.21 vs. 0.65±0.24 cm/mmHg; p=0.0046). Also, in AF patients in comparison to SR group some parameters had worse values: s' (9.7±2.31 vs. 12.1±3.83, p=0.014), RVEF (37.2±7.3 vs. 48.2±7.5, p<0.0001 and FW RVLS (−18.3±4.6 vs. −23.9±4.23%, p<0,0001). Within the AF group no significant differences in studied variables depending on RV pacing or CRT were found. Conclusions Larger volumes and higher pressure overload of the RV were observed in patients with AF in comparison to SR. Systolic function of the RV seems to be more depressed in AF compared to SR patients with systolic heart failure. Further research in larger groups is required to identify the most applicable and valuable methods of RV evaluation.


Author(s):  
Maria Isabel Toulson Davisson Correia ◽  
Carolina Trancoso de Almeida

2019 ◽  
Vol 6 (1) ◽  
pp. 15 ◽  
Author(s):  
Josue Chery ◽  
Shan Huang ◽  
Lianghui Gong ◽  
Shuyun Wang ◽  
Zhize Yuan ◽  
...  

Right ventricle (RV) failure secondary to pressure overload is associated with a loss of myocardial capillary density and an increase in oxidative stress. We have previously found that human neonatal thymus mesenchymal stem cells (ntMSCs) promote neovascularization, but the ability of ntMSCs to express the antioxidant extracellular superoxide dismutase (SOD3) is unknown. We hypothesized that ntMSCs express and secrete SOD3 as well as improve survival in the setting of chronic pressure overload. To evaluate this hypothesis, we compared SOD3 expression in ntMSCs to donor-matched bone-derived MSCs and evaluated the effect of ntMSCs in a rat RV pressure overload model induced by pulmonary artery banding (PAB). The primary outcome was survival, and secondary measures were an echocardiographic assessment of RV size and function as well as histological studies of the RV. We found that ntMSCs expressed SOD3 to a greater degree as compared to bone-derived MSCs. In the PAB model, all ntMSC-treated animals survived to the study endpoint whereas control animals had significantly decreased survival. Treatment animals had significantly less RV fibrosis and increased RV capillary density as compared to controls. We conclude that human ntMSCs demonstrate a therapeutic effect in a model of chronic RV pressure overload, which may in part be due to their antioxidative, antifibrotic, and proangiogenic effects. Given their readily available source, human ntMSCs may be a candidate cell therapy for individuals with congenital heart disease and a pressure-overloaded RV.


1991 ◽  
Vol 260 (4) ◽  
pp. H1087-H1097
Author(s):  
J. E. Calvin

The purpose of this study was to determine whether segment lengths measured from the right ventricular inflow and outflow tract regions of the right ventricle would accurately reflect true volume changes of the right ventricle and to determine the response of the right ventricle to afterload increases induced by both constricting the pulmonary artery (PAC) and embolizing the pulmonary circulation with glass beads (GBE). Three excised hearts were instrumented with segment-length crystals attached to the inflow and outflow tract regions, and saline was instilled into a balloon implanted inside the right ventricular cavity. The experiments showed a high correlation (r greater than or equal to 0.90 in all cases) between static segment lengths and volume instilled. In open chest, open pericardial canine experiments, vena caval occlusion reduced end-diastolic segments lengths and right ventricular systolic pressure consistent with a reduction in right ventricular end-diastolic volume. In a separate group of animals, volume loading with dextran increased inflow and outflow end-diastolic segment lengths and increased cardiac output. In two further groups of animals, one of which was pretreated intravenously with propranolol (Inderal), both forms of pressure overload increased end-diastolic lengths in both regions. However, GBE increased right ventricular stroke work compared with PAC. We conclude that end-diastolic segment lengths reflect true volume changes of the right ventricle. Furthermore, during acute pressure overload, the right ventricle dilates to compensate for the afterload change. However, ventricular function is better maintained after GBE.


Author(s):  
Mark Harrison

This chapter describes metabolic response to insult as it applies to Emergency Medicine, and in particular the Primary FRCEM examination. The chapter outlines the key details of the control of energy production, and the metabolic response to stress including injury, infection, infarction, temperature, and burns. This chapter is laid out exactly following the RCEM syllabus, to allow easy reference and consolidation of learning.


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