Yoga Practitioners Exhibit Higher Parasympathetic Activity and Baroreflex Sensitivity and Better Adaptability to 40 mm Hg Lower-Body Negative Pressure

Yoga has been shown to improve autonomic conditioning in humans, as evidenced by the enhancement of parasym-pathetic activity and baroreflex sensitivity. Therefore, we hypothesized that the experience of yoga may result in adaptation to acute hemodynamic changes. To decipher the long-term effects of yoga on cardiovascular variability, yoga practitioners were compared to yoga-naïve subjects during exposure to –40 mm Hg lower-body negative pressure (LBNP). A comparative study was conducted on 40 yoganaïve subjects and 40 yoga practitioners with an average age of 31.08 ± 7.31 years and 29.93 ± 7.57 years, respectively. Heart rate variability, blood pressure variability, baroreflex sensitivity, and correlation between systolic blood pressure and RR interval were evaluated at rest and during LBNP. In yoga practitioners, the heart rate was lower in supine rest (p = 0.011) and during LBNP (p = 0.043); the pNN50 measure of heart rate variability was higher in supine rest (p = 0.011) and during LBNP (p = 0.034). The yoga practitioners’ standard deviation of successive beat-to-beat blood pressure intervals of systolic blood pressure variability was lower in supine rest (p = 0.034) and during LBNP (p = 0.007), with higher sequence baroreflex sensitivity (p = 0.019) and ~ high-frequency baroreflex sensitivity. Mean systolic blood pressure and RR interval were inversely correlated in the yoga group (r = –0.317, p = 0.049). The yoga practitioners exhibited higher parasympathetic activity and baroreflex sensitivity with lower systolic blood pressure variability, indicating better adaptability to LBNP compared to the yoga-naïve group. Our findings indicate that the yoga module was helpful in conditions of hypovolemia in healthy subjects; it is proposed to be beneficial in clinical conditions associated with sympathetic dominance, impaired barore-flex sensitivity, and orthostatic intolerance.

Effect of Sleep Bruxism Intensity on Blood Pressure in Normotensives

The present research aimed to investigate the influence of sleep bruxism (SB) intensity on blood pressure parameters in normotensive subjects by using an ambulatory blood pressure device. The study group included 65 normotensive individuals suspected of having SB. All participants underwent one-night video-polysomnography, and ambulatory blood pressure monitoring was performed the next day; 86.15% of them were diagnosed with SB. Statistical analysis included correlation and regression analysis. The obtained results showed that systolic blood pressure variability during sleep significantly increased in individuals with BEI > 4 (bruxism episodes index; episodes/hour) compared to those with BEI ≤ 4 (8.81 ± 3.36 versus 10.57 ± 3.39, p = 0.05). Multivariable regression analysis showed that systolic blood pressure variability at nighttime was also associated with the following independent risk factors: higher apnea-to-bruxism index, male gender, BEI > 4 episodes/hour, body mass index (BMI) ≥ 25 kg/m2, higher arousal index, and shorter total sleep time. In summary, sleep bruxism intensity was associated with increased systolic blood pressure variability during sleep. Coincidental apnea, male gender, severe sleep bruxism (SB intensity with BEI > 4/hour), excess weight and obesity, higher arousal index, and shorter sleep time seem to be the main determinants that influence blood pressure in normotensive sleep bruxers.

Abstract MP33: Association Between Neurologic Outcomes and Temporal Profile of Systolic Blood Pressure Variability After Endovascular Thrombectomy

Introduction: Higher systolic blood pressure variability (BPV) after endovascular thrombectomy (EVT) has been associated with an increased risk of hemorrhagic transformation and worse functional outcomes. However, the time-varying behavior of BPV after EVT and its effects on functional outcome have not been well characterized. Methods: We analyzed data from an international cohort of patients with acute large-vessel occlusion stroke who underwent EVT at 11 centers across North America, Europe, and Asia. Repeated time-stamped blood pressure data were recorded for the first 72 hours after thrombectomy. Parameters of BPV were calculated in 12-hour epochs using five established methodologies: standard deviation (SD), coefficient of variation (CV), average real variability (ARV), successive variation (SV), and residual SD (rSD). Patients’ overall mean BPV was then used to assign patients into tertiles for regression analysis: low BPV, intermediate BPV, and high BPV. Functional outcome was measured with the modified Rankin Scale (mRS) at 90 days. Results: Of the 1,791 patients (age 69 ± 14, NIHSS 15 ± 6) included in our analysis, 1,085 (60.6%) had a poor 90-day outcome (mRS >3). Patients with poor outcome had significantly higher systolic BPV (p<0.05) measured as standard deviation (SBP SD) at each epoch (Figure 1B). Compared to patients with low BPV, those in the highest tertile group had significantly greater odds of a poor functional outcome after adjusting for age, sex, hypertension, NIHSS, ASPECT, tPA, time to reperfusion, and TICI score (OR 1.5; 95% CI 1.2-2; p=0.001). Patients in the highest tertile of BPV demonstrated time-dependent variability with the highest SBP SD during the first 24 hours after thrombectomy (Figure 1A). Conclusions: Higher BPV measured by SBP SD appears to be associated with poor 90-day outcome in EVT-treated stroke patients. Early treatment strategies targeting early high BPV warrant further prospective investigation.