[Right ventricular function: physiological and physiopathological features].
Sinus and conus constitute the two cavities of the right ventricle. They are anatomically and functionally different. The sinus is a flow-generator and the conus a pressure-regulator. The coronary circulation of the right ventricle is provided by the right coronary artery and the left anterior descending artery. The right ventricle is perfused during systole and diastole. When oxygen demand increases, coronary arteries dilate and oxygen extraction rises. As for the left ventricle, right ventricular performance depends upon heart rate, rhythm, contractility and loading conditions. Ventricular interactions are very important for right ventricular function. Loading conditions and contractility of the left ventricle are of major significance for right ventricular performance. For the right ventricle, the end of the ejection is different from the end of the active contraction. The time between them allows to achieve ventricular emptying. This duration is linked to afterload. Presently, it is impossible to accurately and simply assess these conditions. Pressure and volume overloadings result in right ventricular failure. They are responsible for ventricular dilation and ischaemia with a decrease in cardiac output, generating a vicious circle. Treatment includes the removal of the cause, and the maintenance of systemic arterial pressure and biventricular contractility. It is difficult to assess the effects of intravenous vasodilators on right ventricular afterload.
Centre de traitement des brûlés (Dr Carsin), HIA Percy, Clamart, France.
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Stephanazzi
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Guidon-Attali
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Escarment
D003326:Coronary Circulation / Q000502:physiology; D006801:Humans; D009200:Myocardial Contraction / Q000502:physiology; D015635:Radionuclide Ventriculography; D013815:Thermodilution; D018497:Ventricular Dysfunction, Right / Q000503:physiopathology* / Q000628:therapy; D016278:Ventricular Function, Right / Q000502:physiology