title: Modified carotid sinus massage using an ultrasonography for maximizing vagal tone: a crossover simulation study.
abstract: BACKGROUND
  The aim of this study was to ascertain if a modified carotid sinus massage (CSM) using ultrasonography is superior to the conventional CSM for vagal tone generation.
  
  
  METHODS
  This was a prospective, crossover, clinical trial including 30 subjects with sinus rhythm. Participants were paired, and they performed 2 types of CSM to each other. To perform the conventional technique, pressure was exerted at the point where the maximal impulse of the carotid pulse was palpated. In the modified technique, participants localized the point of maximal diameter just above the bifurcation of the common carotid artery using ultrasonography and applied pressure to that point. Mean differences between premaneuver and postmaneuver R-R intervals and heart rates were compared. The distance from the midline of the neck (x distance) to the angle of the mandible (y distance) was measured, and the mean distance between the 2 techniques was compared.
  
  
  RESULTS
  The baseline mean premaneuver R-R interval and heart rate did not differ significantly between the 2 techniques. The postmaneuver R-R interval and heart rate as well as the mean R-R interval and heart rate differences were significantly greater in the modified CSM. The mean location determined using the modified CSM was located 0.8 cm lateral and 0.8 cm superior to the mean location of the conventional CSM.
  
  
  CONCLUSIONS
  The modified CSM using ultrasonography might be more useful than the conventional CSM in reverting episodes of paroxysmal supraventricular tachycardia and may be a suitable alternative for treating the same in the emergency department.
authors.affiliation: Department of Emergency Medicine, School of Medicine, Hallym University, 445 Gil-dong, Gang-dong gu, Seoul 134-701, Republic of Korea.
authors.forename: Seung Min
authors.initials: SM
authors.lastname: Ha
authors.affiliation: Department of Emergency Medicine, School of Medicine, Hallym University, 445 Gil-dong, Gang-dong gu, Seoul 134-701, Republic of Korea.
authors.forename: Young Suk
authors.initials: YS
authors.lastname: Cho
authors.affiliation: Department of Emergency Medicine, School of Medicine, Hallym University, 445 Gil-dong, Gang-dong gu, Seoul 134-701, Republic of Korea. Electronic address: emdrcho@empas.com.
authors.forename: Gyu Chong
authors.initials: GC
authors.lastname: Cho
authors.affiliation: Department of Emergency Medicine, School of Medicine, Hallym University, 445 Gil-dong, Gang-dong gu, Seoul 134-701, Republic of Korea.
authors.forename: Choong Hyun
authors.initials: CH
authors.lastname: Jo
authors.affiliation: Department of Emergency Medicine, School of Medicine, Hallym University, 445 Gil-dong, Gang-dong gu, Seoul 134-701, Republic of Korea.
authors.forename: Ji Young
authors.initials: JY
authors.lastname: Ryu
mesh_terms: D000328:Adult; D002346:Carotid Sinus / Q000000981:diagnostic imaging*; D018592:Cross-Over Studies; D004562:Electrocardiography; D005260:Female; D064368:Healthy Volunteers; D006339:Heart Rate; D006801:Humans; D008297:Male; D008405:Massage / Q000379:methods*; D011446:Prospective Studies; D013614:Tachycardia, Paroxysmal / Q000628:therapy; D013617:Tachycardia, Supraventricular / Q000628:therapy; D014463:Ultrasonography