Effect of thoracotomy upon the carotid sinus control of regional hemodynamics in the dog

The effects of bilateral thoracotomy upon the operating characteristics of the carotid sinus reflex were examined in 11 vagotomized dogs. Pressure-flow relationships in the aorta, celiac, mesenteric, renal, and femoral arteries were studied as a function of pressure in the isolated carotid sinuses. These relationships were analyzed to give the carotid sinus reflex operating point values and sensitivities of pressure, flow, impedance, and power for each regional vascular bed. Following thoracotomy there was a significant fall in the closed-loop operating point pressure (CLOP) (p