Abstract
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.