Decreased LF/HF ratio is associated with worse outcomes in patients who received mechanical thrombectomy under general anesthesia for emergent large vessel occlusion: a retrospective study

Head-to-Head Comparison of Electroacupuncture and Laser Acupuncture Effects on Autonomic Regulation and Clinical Effects in Dysmenorrhea: A Randomized Crossover Clinical Trial

Introduction: Electroacupuncture (EA) has been applied in dysmenorrhea and has shown good efficacy. The mechanisms of EA are associated with autonomic nervous system adjustments and neuroendocrine regulation. Laser acupuncture (LA), however, has been widely investigated for its noninvasiveness. However, it remains uncertain whether LA is as effective as EA. This study aimed to compare EA and LA head to head in dysmenorrhea. Methods: A crossover, randomized clinical trial was conducted. EA or LA was applied to selected acupuncture points. Participants were randomized into two sequence treatment groups who received either EA or LA twice per week in luteal phase for 3 months followed by 2-month washout, then shifted to other groups (sequence 1: EA > LA; sequence 2: LA > EA). Outcome measures were heart rate variability (HRV), prostaglandins (PGs), pain, and quality-of-life (QoL) assessment (QoL-SF12). We also compared the effect of EA and LA in low and high LF/HF (low frequency/high frequency) status. Results: Totally, 43 participants completed all treatments. Both EA and LA significantly improved HRV activity and were effective in reducing pain (Visual Analog Scale [VAS]; EA: p < 0.001 and LA: p = 0.010) and improving QoL (SF12: EA: p < 0.001, LA, p = 0.017); although without intergroup difference. EA reduced PGs significantly (p < 0.001; δ p = 0.068). In low LF/HF, EA had stronger effects than LA in increasing parasympathetic tone in respect of percentage of successive RR intervals that differ by more than 50 ms (pNN50; p = 0.053) and very low-frequency band (VLF; p = 0.035). Conclusion: There is no significant difference between EA and LA in improving autonomic nervous system dysfunction, pain, and QoL in dysmenorrhea. EA is prominent in PGs changing and preserving vagus tone in low LF/HF; yet LA is noninvasive for those who have needle phobia. Whether LA is equivalent with EA and the mechanism warrants further study. Clinical trial identification number: NCT04178226.

Heart rate variability as a predictor of stroke course, functional outcome, and medical complications: A systematic review

Background: Heart rate variability (HRV) is a non-invasive marker of autonomic nervous system function that is based on the analysis of length differences between subsequent RR intervals of the electrocardiogram. The aim of this systematic review was to assess the current knowledge gap in the utility of HRV parameters and their value as predictors of the acute stroke course. Methods: A systematic review was performed in accordance with the PRISMA guidelines. Relevant articles published between 1 January 2016 and 1 November 2022 available in the PubMed, Web of Science, Scopus, and Cochrane Library databases were obtained using a systematic search strategy. The following keywords were used to screen the publications: "heart rate variability" AND/OR "HRV" AND "stroke." The eligibility criteria that clearly identified and described outcomes and outlined restrictions on HRV measurement were pre-established by the authors. Articles assessing the relationship between HRV measured in the acute phase of stroke and at least one stroke outcome were considered. The observation period did not exceed 12 months. Studies that included patients with medical conditions influencing HRV with no established stroke etiology and non-human subjects were excluded from the analysis. To minimize the risk of bias, disagreements throughout the search and analysis were resolved by two independent supervisors. Results: Of the 1,305 records obtained from the systematic search based on keywords, 36 were included in the final review. These publications provided insight into the usability of linear and non-linear HRV analysis in predicting the course, complications, and mortality of stroke. Furthermore, some modern techniques, such as HRV biofeedback, for the improvement of cognition performance after a stroke are discussed. Discussion: The present study showed that HRV could be considered a promising biomarker of a stroke outcome and its complications. However, further research is needed to establish a methodology for appropriate quantification and interpretation of HRV-derived parameters.

The Dosage Effect of Laser Acupuncture at PC6 (Neiguan) on Heart Rate Variability: A Pilot Study

Laser acupuncture (LA) has been more applicated in the clinical practice with good responses, but the dosage and parameter settings are still inconsistent with the arguments. This study is focused on the effect of LA on heart rate variability (HRV) with different energy density (ED). Based on the Arndt-Schulz law, we hypothesized that the effective range should fall within 0.01 to 10 J/cm² of ED, and settings above 10 J/cm² would perform opposite or inhibitory results. We recruited healthy adults in both sexes as subjects and choose bilateral PC6 (Neiguan) as the intervention points to observe the HRV indexes changes by an external wrist autonomic nerve system (ANS) watch on the left forearm. The data from the ANS watch, including heart rate, blood pressure, and ANS activity indexes, such as low frequency (LF), high frequency (HF), LF%, HF%, LF/HF ratio, and so on, were analyzed by the one-way ANOVA method to test the possible effect. In this study, every subject received all three different EDs of LA in a randomized order. After analyzing the data of 20 subjects, the index of HF% was upward and LF/HF ratio was downward when the ED was 7.96 J/cm². Otherwise, the strongest ED 23.87 J/cm² performed the opposite reaction. Appropriately, LA intervention could affect the ANS activities, with the tendency to increase the ratio of parasympathetic and decrease the ratio of sympathetic nerve system activities with statistically significant results, and different ED interventions are consistent with Arndt-Schulz law with opposite performance below and above 10 J/cm².