Boosting cardiac interoceptive awareness in borderline hypertension: from virtual reality to mindfulness-base interventions

Introduction Hypertension is a complex, multifactorial medical condition characterized by high blood pressure levels. It is one of the most prevalent pathologies in Western countries and a main risk factor for developing several clinical conditions, including silent but fatal cardiac events. Experimental evidence suggests that compared to normotensives, individuals with hypertension have reduced interoceptive abilities and decreased pain perception, resulting in blood pressure-related hypoalgesia. Here, we present two ongoing studies; the first explores the relationship between interoception, blood pressure and pain perception in borderline hypertensives (BH) vs healthy controls (HC). The second uses virtual reality (VR) to increase interoception with the final aim of normalizing pain perception. Methods Twenty-three BH (mean age=34.04; SD=12.02) and 23 HC, matched for sex and age (mean age=34.52; SD=12.09), participated in the first study. We collected hemodynamic, interoceptive accuracy, pain perception and personality measures. In the second ongoing study, we tested 8 BH (mean age 30.25 years, SD=13.94). Participants were randomly assigned to a five-day VR (N=5) or mindfulness-based intervention. The VR intervention consisted of embodiment sessions where participants viewed their virtual body from a first-person perspective, flashing synchronously with their heartbeat. The mindfulness-based intervention consisted of guided breathing exercises. The same measures as those of Study 1 were collected pre- and post-intervention. Results As expected, we found a significant difference between the two groups regarding blood pressure, with BH individuals showing higher values. Differently from our hypotheses, we did not find any difference in interoception and pain perception between the two groups. Interestingly, only in the BH group, we found a significant negative correlation between pain threshold and interoceptive sensitivity. Descriptive analyses performed on study 2 instead suggest that the two trainings can be used to increase participants’ ability to perceive their own heartbeats. Discussion Although our preliminary findings do not support the literature, as no differences in pain perception emerged between the two groups, it seems that interoception might play a crucial role in the phenomenon of blood pressure-related hypoalgesia. The lower the participants’ cardiac awareness, the higher their pain threshold. Accordingly, preliminary results from Study 2 seem to suggest that both an intervention involving cardio-visual coupling and embodied virtual agents, as well as a mindfulness-based intervention where participants focus on breathing signals, significantly increase participants’ ability to perceive their internal signals. Together, these findings suggest that enhancing interoception may be relevant in patients with BH to normalize their pain perception ultimately.