Cardiac versus peripheral effects of left stellate ganglion stimulation

¹ Departments of Physiology and Medicine, Georgetown University School of Medicine, Washington, D. C.

The direct effects of left stellate ganglion stimulation were studied in dogs with an intact circulation and with the left ventricle bypassed. In both preparations left stellate stimulation was associated with an increase in myocardial contractile force, an elevation in pulmonary arterial pressure, and no change or a slight fall in right atrial pressure. Before left ventricular bypass, left stellate stimulation was accompanied by a rise in both systolic (+46 mm Hg) and diastolic (+22 mm Hg) pressure. With the left ventricle eliminated from the circulation and systemic flow controlled with a mechanical pump, changes in systolic (+13 mm Hg) and diastolic (+7 mm Hg) pressure were negligible. These observations confirm that the hypertensive response is due predominantly to augmented cardiac output and that peripheral vasoconstriction plays a minor role.