title: The effect of patient position and MAST inflation on carotid sinus diameter.
abstract: A comparison of several maneuvers that are believed to increase vagal tone was made by measuring the carotid sinus with an ultrasound device. For 20 healthy volunteers the mean carotid sinus diameter was 5.7 mm supine, 6.1 mm in the Trendelenberg position, 6.5 mm after supine medical antishock trousers (MAST) inflation, 7.0 mm after MAST inflation in the Trendelenberg position, and 7.3 mm during a headstand. Each mean value was significantly different (P less than .01) from each of the others. These results have important implications for the treatment of dysrhythmias such as paroxysmal supraventricular tachycardia.
mesh_terms: D000328:Adult; D002346:Carotid Sinus / Q000033:anatomy & histology*; D004635:Emergency Medicine; D005676:Gravity Suits; D006801:Humans; D011187:Posture; D013610:Tachycardia / Q000628:therapy