Role of variations in pulmonary and cardiac hemodynamics in the reduction of the venous return during experimental ischemia of the left ventricular myocardium.
During left-ventricular myocardial ischemia, the decrease in the venous return is determined by reduction of cardiac output, which results from heart rate deceleration and decrease in left-ventricular stroke volume. The latter is related to a decrease in myocardial contractility and blood storage in the pulmonary circuit. Blood accumulation in the lungs is not observed during stimulation of the vagus nerve or treatment with propranolol (against the background of the same values of the negative chronotropic and inotropic effects as during myocardial ischemia). The left-ventricular stroke volume increases, while the cardiac output and venous return decrease to a lesser extent under these conditions.
Department for Physiology of Visceral Systems, Institute of Experimental Medicine, Northwestern Division of the Russian Academy of Medical Sciences, St. Petersburg, Russia. viespbru@mail.ru
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Evlakhov
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Poyassov
D000818:Animals; D001794:Blood Pressure / Q000187:drug effects; D002415:Cats; D004558:Electric Stimulation; D006321:Heart / Q000187:drug effects / Q000503:physiopathology*; D006339:Heart Rate / Q000187:drug effects; D006352:Heart Ventricles / Q000503:physiopathology; D008168:Lung / Q000098:blood supply / Q000187:drug effects / Q000503:physiopathology; D009200:Myocardial Contraction / Q000187:drug effects; D017202:Myocardial Ischemia / Q000503:physiopathology*; D011433:Propranolol / Q000008:administration & dosage; D011651:Pulmonary Artery / Q000187:drug effects / Q000503:physiopathology*; D011817:Rabbits; D013318:Stroke Volume / Q000187:drug effects; D014630:Vagus Nerve / Q000187:drug effects / Q000503:physiopathology; D014665:Vasodilator Agents / Q000008:administration & dosage; D018487:Ventricular Dysfunction, Left / Q000503:physiopathology*
D014665:Vasodilator Agents; D011433:Propranolol