Pilot study for a novel delta carotid sinus massage in increasing parasympathetic tone: a randomized, prospective, cross-over, comparative study with conventional method

ABSTRACT

OBJECTIVE: This study examined the efficacy of new delta carotid sinus massage (CSM) versus conventional CSM (CM). METHODS: This prospective, cross-over study was conducted on 26 healthy volunteers with a normal sinus rhythm. CM and delta CSM (DM) were performed in all participants. In both cases, the CSM was performed, where the maximal carotid pulse was palpated. DM differed from CM in that the physician moves the palpating finger in the opposite direction of the carotid pulse at least twice. The mean and longest R-R intervals and mean and lowest heart rates (HRs) at the baseline and during the procedure for each technique were compared. The mean differences between the baseline and procedure R-R intervals and the HRs for each technique were also evaluated. RESULTS: The baseline mean and longest R-R intervals and baseline mean and lowest HRs were similar both groups (P>0.05). The procedure DM mean and longest R-R intervals (22.7±3.1, 26.4±4.9) were significantly greater than the CM corresponding values (22.0±3.1, 24.6±3.5; P<0.001, P=0.003). Procedure DM mean and lowest HRs (67.3±9.7, 58.6±10.7) were significantly lower than the CM corresponding values (69.4±10.0, 61.8±8.9; P=0.001, P=0.003). The differences in the R-R interval and HR between the procedure and baseline were significant (mean and longest R-R intervals with CM [1.3±1.5 and 2.1±1.9] vs. DM [2.0±1.4 and 3.8±3.1], P<0.001, P=0.004; mean and lowest HRs with CM [4.2±4.3 and 5.8±4.6] vs. DM [6.3±4.6 and 9.1±6.5], P<0.001, P=0.005). CONCLUSION: DM is more effective in generating a more potent vagal tone than CM.