Graphical analysis of cardiac output curve and venous return curve in the dog heart-lung preparation - with special reference to the pulmonary circulation ( II ).

Observations were made on the changes in cardiac function in the dog heart-lung preparation, brought about by stimulation of the left stellate ganglion, and were compared with observations obtained when the heart was driven by an artificial pacemaker, as well as with changes produced by epinephrine administration. During left stellate ganglion stimulation, cardiac output increased approximately 79%; stroke volume showed a mean increase of 55%, whereas the heart rate had a mean increase of 19%. When the heart was driven by an artificial pacemaker, cardiac output showed no change; heart rate had a mean increase of 28%. The stroke volume, on the other hand, decreased 22% below the control value. It is concluded that left stellate ganglion stimulation in the dog heart-lung preparation causes significant increases in both the stroke volume and heart rate.

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Role of the Pulmonary Circulation in the Distribution of Human Fetal Cardiac Output During the Second Half of Pregnancy

Circulation ◽

10.1161/01.cir.94.5.1068 ◽

1996 ◽

Vol 94 (5) ◽

pp. 1068-1073 ◽

Cited By ~ 204

Author(s):

Juha Rasanen ◽

Dennis C. Wood ◽

Stuart Weiner ◽

Abraham Ludomirski ◽

James C. Huhta

Keyword(s):

Cardiac Output ◽

Pulmonary Circulation

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Alterations in Systemic Vascular Volume of the Dog in Response to Hexamethonium and Norepinephrine

American Journal of Physiology-Legacy Content ◽

10.1152/ajplegacy.1957.191.2.283 ◽

1957 ◽

Vol 191 (2) ◽

pp. 283-286 ◽

Cited By ~ 35

Author(s):

John C. Rose ◽

Edward D. Freis

Keyword(s):

Cardiac Output ◽

Venous Return ◽

Cardiac Activity ◽

Left Ventricular ◽

Vascular Volume ◽

Vasomotor Activity ◽

Constant Output ◽

Arteriolar Tone ◽

Integrated Responses

A diaphragm pump of controlled constant output was substituted for the left ventricle in dogs. Left auricular blood was conducted to a reservoir, from which it was pumped into the thoracic aorta. Left ventricular by-pass was complete. Alterations in total vascular volume were continually monitored by observation of the pump reservoir level. Sympathetic blockade (hexamethonium) increased total vascular volume (mean 15%). This resulted in decreased venous return and decreased right ventricular output. Norepinephrine constricted the total vasculature and decreased vascular volume (mean 12%). This resulted in increased venous return and cardiac output. These experiments demonstrated the complex integrated responses of the total circulation to sympathetic vasomotor activity. The role of the sympathetic nervous system not only in the regulation of arteriolar tone and cardiac activity but also in adjusting total vascular volume and venous return was emphasized. Venous return, and hence cardiac output alterations accompanying systemic vasomotor activity can only be detected by continuous methods of flow measurement.

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