Aim: 

Studies (Jambrik et al 2004; 2005) on flow-mediated vascular dilation (FMD) in subjects with high (Highs) and low (Lows) hypnotizability showed lower reduction of FMD ("endothelial dysfunction") in Highs during nociceptive stimulation with (AN) and without suggestions for analgesia (PAIN) and during mental computation (MC). The experiment investigates the role of hemodynamic factors possibly modulating shear stress differentially and, thus, accounting for the hypnotizability-related FMD differences. The cardiovascular correlates of pain imagery (IM) were also studied because they might affect the shift from acute to chronic pain.

Methods: 

Heart rate, blood pressure and skin blood flow were monitored during basal conditions, PAIN, AN, MC and IM (2 min each) in non hypnotized Highs (n=20) and Lows (n=20).

Results: 

The results did not show any difference between Highs and Lows in the stimulation-related changes in heart rate and blood pressure, while the skin mean blood flow changed only in Lows.

Conclusions: 

The local activity of vasoactive factors, i. e. nitric oxide and endothelin 1, rather than sympathetically-mediated control, is responsible for the hypnotizability-related FMD differences observed. Results do not confirm that High may be more prone than Lows to a shift from acute to chronic pain because of a more pronounced autonomic response to pain imagery and indirectly support the hypothesis of a lower vulnerability of Highs to cardiovascular disease.