Objective: The aim of this study was to compare blood pressure (BP) behavior and heart rate variability (HRV) among hypertensive stage I and normotensive individuals who were submitted to the cranial technique of the 4th ventricle compression (CV4), an osteopathic technique.

Methods: In this experimental controlled study, thirty men between 40 and 60 years old were evaluated and divided into two groups: normotensive (NT) and hypertensive (HT). The CV4 maneuver was applied in both groups and BP was measured at 5 (five) different stages: pre and post-intervention, 5, 10 and 15min after technique. Time-frequency parameters were obtained from measurements of RR intervals. Data were analyzed using an ANOVA two-way for analysis of the condition factor (NT and HT) and times with p-value ≤ .05.

Results: There was a reduction in the BP of the HT group. A significant intergroup difference (p = .01) was noticed, with respect to the standard deviation of successive normal R-R intervals (SDNN) values, mainly between pre-intervention and 15min stages. Concerning root mean square of the mean squared differences (RNSSD) values, the highlights were differences between pre-intervention and 10min (p = .01) only in the NT group. There was an increase in high frequencies (HF) values and a low frequencies (LF) attenuation in both groups at all different stages.

Conclusion: The data showed a BP reduction in the HT group in pre-intervention/15min and an increase in parasympathetic activity and decreased sympathetic activity in both groups. This suggests a change in the sympathetic-vagal balance. However, further studies are needed to elucidate the data on BP reduction mechanisms with CV4.