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Purpose This study aimed to design a device to monitor mouth puffing phenomena of patients with obstructive sleep apnea when mouth-taped and to employ video recording and computing algorithms to double-check and verify the efficacy of the device. Methods A mouth puffing detector (MPD) was developed, and a video camera was set to record the patients’ mouth puffing phenomena in order to make ensure the data obtained from the device was appropriate and valid. Ten patients were recruited and had polysomnography. A program written in Python was used to investigate the efficacy of the program’s algorithms and the relationship between variables in polysomnography (sleep stage, apnea-hypopnea index or AHI, oxygen-related variables) and mouth puffing signals (MPSs). The video recording was used to validate the program. Bland–Altman plot, correlations, independent sample t-test, and ANOVA were analyzed by SPSS 24.0. Results Patients were found to mouth puff when they sleep with their mouths taped. An MPD was able to detect the signals of mouth puffing. Mouth puffing signals were noted and categorized into four types of MPSs by our algorithms. MPSs were found to be significantly related to relative OSA indices. When all participants’ data were divided into minutes, intermittent mouth puffing (IMP) was found to be significantly different from non-mouth puffing in AHI, oxygen desaturation index (ODI), and time of oxygen saturation under 90% (T90) (AHI: 0.75 vs. 0.31; ODI: 0.75 vs. 0.30; T90: 5.52 vs. 1.25; p p Conclusions This study established a simple way to detect mouth puffing phenomena when patients were mouth-taped during sleep, and the signals were classified into four types of MPSs. We propose that MPSs obtained from patients wearing the MPD can be used as a complement for clinicians to evaluate OSA.

Bright morning light (BML) entrains the body clock, modulates circadian rhythm, and improves sleep-wake disturbances. However, its impact on the autonomic nervous system (ANS) at night remains unclear. Hence, we investigated the effects of BML exposure on activities of the parasympathetic nervous system (PSNS) and sympathetic nervous system (SNS) at night. This non-randomized controlled pilot study included participants ≥60 years, diagnosed with a type of dementia or cognitive disorder. We excluded participants with pacemakers. The treatment group received 2500 lx BML, whereas the control group received approximately 200 lx of general lighting. We measured the heart rate variability to quantify ANS activity. The treatment group displayed significantly increased high-frequency (HF) power (Roy's largest root=2.44; P

Exposure to bright morning light (BML) entrains the master circadian clock, modulates physiological circadian rhythms, and reduces sleep–wake disturbances. However, its impact on the autonomic nervous system at night remains unclear. Here, we investigated the effects of BML exposure on parasympathetic nervous system (PSNS) and sympathetic nervous system (SNS) activity at night in elderly women. This nonrandomized controlled pilot study included female participants aged ≥ 60 years who were diagnosed with a type of dementia or cognitive disorder, excluding individuals with pacemakers. The treatment group was exposed to 2500 lx of BML, whereas the control group was exposed to 200 lx of general lighting. We measured heart rate variability to quantify ANS activity. The treatment group displayed significant increases in high-frequency (HF) power (Roy’s largest root = 1.62; p < 0.001) and nonsignificant decreases in normalized low-frequency (LF%) power. The corresponding nonsignificant decreases in the low-frequency/high-frequency (LF/HF) ratio and cognitive function were correlated with PSNS activity (Roy’s largest root = 1.41; p < 0.001), which improved severe dementia. BML exposure reduced SNS activity and enhanced PSNS activity at night in female participants, which improved cognitive function. Thus, BML therapy may be a useful clinical tool for alleviating cognitive decline.

Background The diagnosis of acute mountain sickness, which lacks a reliable and objective diagnostic tool, still depends on the clinical symptoms and signs and remains a major threat and unpredictable disease affecting millions of mountaineers. Objectives To record electroencephalography signals with small, convenient, wireless equipment and to test whether electroencephalography parameters, which are more sensitive and reliable markers, could predict the symptoms of acute mountain sickness. Methods Twenty-five participants were enrolled and separated into two groups to climb Mount Jade in Taiwan. We collected electrocardiography signals and arterial oxygen saturation data at ground, moderate (2,400 m), and high altitude (3,400 m). A spectral analysis of the electrocardiography was performed to assess the study subjects’ electroencephalography activity at different frequencies (α, β, θ, δ) and the mean power frequency of electrocardiography. The clinical symptoms and Lake Louise Acute Mountain Sickness scores of the subjects were recorded for comparison. Results A significant change in the δ power of electroencephalography was recorded in subjects ascending from the ground to a high altitude of 3,400 m in a 4-day itinerary. In addition, between the two groups of subjects with and without acute mountain sickness (Lake Louise Acute Mountain Sickness scores < 3 and ≥ 3), the δ power of electroencephalography at the fronto-parietal 1 and parietal 3 electrodes at moderate altitude as well as the changes of δ power and mean power frequency of electrocardiography over parietal 4 at high altitude showed a significant difference. At moderate altitude, the increasing δ power of electroencephalography at the parietal 4 electrode was related to the headache symptom of acute mountain sickness before ascending to high altitude. Conclusion At moderate altitude, the δ power increase of electroencephalography at the P4 electrode could be a predictor of acute mountain sickness symptoms before ascending to high altitude. Thus, electroencephalography had the potential to identify the risk of acute mountain sickness.

Autonomic dysfunction and sleep problems are closely associated with hypertension and predict cardiovascular morbidity and mortality. Animal studies and clinical observations have identified exercise as an important factor in preventing and treating hypertension. However, the roles of autonomic function and sleep in the antihypertensive mechanisms of exercise are still not fully understood. This study aimed to clarify the physiological mechanisms associated with autonomic function and sleep through wheel exercise. Male spontaneously hypertensive rats (SHRs) were grouped into a wheel-exercised group and a sedentary group (controls). Electroencephalogram, electromyogram, electrocardiogram, and mean arterial pressure (MAP) were recorded simultaneously for 24 h once a week over 11 weeks. Wheel exercise was initiated in the SHRs at 12 weeks old and continued for another eight weeks. A significant suppression in the age-related elevation of MAP was noted in the SHRs undergoing wheel exercise. The reduction in MAP was correlated with increased parasympathetic activity and baroreflex sensitivity and decreased sympathetic activity, mainly during quiet sleep. Exercise increased the paradoxical sleep time and theta power (associated with cognitive function) but not the delta power (an indicator of sleep depth) or the attenuation of circadian rhythm flattening (characterized by increased wakefulness and less sleep during the light period and the opposite during the dark period). Furthermore, the exercise-induced changes in autonomic function occurred before those in sleep patterns, which were dependent on each other. In conclusion, wheel exercise can modulate sleep-related cardiovascular dysfunction and the flattening of circadian rhythm, preventing the progression of hypertension, which reduces the incidence of cardiovascular diseases.

Before caring for patients, video instruction is commonly used for undergraduate medical students, and 360° virtual reality (VR) videos have gained increasing interest in clinical medical education. Therefore, the effect of immersive 360° VR video learning compared with two-dimensional (2D) VR video learning in clinical skills acquisition should be evaluated. This randomized, intervention-controlled clinical trial was aimed to assess whether immersive 360° VR video improves undergraduate medical students' learning effectiveness and reduces the cognitive load in history taking and physical examination (H&P) training. From May 1 2018 to October 30 2018, 64 senior undergraduate medical students in a tertiary academic hospital were randomized to receive a 10-min immersive 360° (360° VR video group; n = 32) or 2D VR instructional video (2D VR video group; n = 32), including essential knowledge and competency of H&P. The demographic characteristics of the two groups were comparable for age, sex, and cognitive style. The total procedure skill score, physical examination score, learner’s satisfaction score, and total cognitive load in the 360° VR video group were significantly higher than those in the 2D VR video group (effect sizes [95% confidence interval]: 0.72 [0.21–1.22], 0.63 [0.12–1.13], 0.56 [0.06–1.06], and 0.53 [0.03–1.03], respectively). This study suggested that a10-minute 360° VR video instruction helped undergraduate medical students perform fundamental H&P skills as effectively as 2D VR video. Furthermore, the 360° VR video might result in significantly better procedural metrics of physical examinations with higher learner satisfaction despite the higher cognitive load.

Recent animal studies have supported that Lactobacillus plantarum PS128 (PS128) can reduce the severity of anxiety and depression. However, previous studies did not focus on the sleep quality and mood of humans. This study determines whether PS128 reduces the severity of anxiety and depressive symptoms, regulates autonomic nervous system function, and improves sleep quality. Forty participants between 20 and 40 years of age with self-reported insomnia were randomly assigned to two groups, a PS128 group and a placebo group, in a double-blind trial. Participants took two capsules of either PS128 or a placebo after dinner for 30 days. Study measures included subjective depressive symptoms, anxiety and sleep questionnaires, and miniature-polysomnography recordings at baseline and on the 15th and 30th days of taking capsules. Overall, all outcomes were comparable between the two groups at baseline and within the 30-day period, yet some differences were still found. Compared to the control group, the PS128 group showed significant decreases in Beck Depression Inventory-II scores, fatigue levels, brainwave activity, and awakenings during the deep sleep stage. Their improved depressive symptoms were related to changes in brain waves and sleep maintenance. These findings suggest that daily administration of PS128 may lead to a decrease in depressive symptoms, fatigue level, cortical excitation, and an improvement in sleep quality during the deep sleep stage. Daily consumption of PS128 as a dietary supplement may improve the depressive symptoms and sleep quality of insomniacs, although further investigation is warranted.

Virtual reality (VR) applications could be beneficial for education, training, and treatment. However, VR may induce symptoms of simulator sickness (SS) such as difficulty focusing, difficulty concentrating, or dizziness that could impair autonomic nervous system function, affect mental workload, and worsen interventional outcomes. In the original randomized controlled trial, which explored the effectiveness of using a 360° VR video versus a two-dimensional VR video to learn history taking and physical examination skills, only the former group participants had SS. Therefore, 28 undergraduate medical students who participated in a 360° VR learning module were included in this post hoc study using a repeated measures design. Data of the Simulator Sickness Questionnaire (SSQ), heart rate variability (HRV) analysis, Task Load Index, and Mini-Clinical Evaluation Exercise were retrospectively reviewed and statistically analyzed. Ten (36%) participants had mild SS (total score > 0 and ≤ 20), and 18 (64%) had no SS symptom. Total SSQ score was positively related to the very low frequency (VLF) band power, physical demand subscale, and frustration subscale, and inversely related to physical examination score. Using multilevel modeling, the VLF power mediated the relationship between total SSQ score and physical examination score. Furthermore, frustration subscale moderated the mediating effects of the VLF power. Our results highlight the importance of documenting SS to evaluate a 360° VR training program. Furthermore, the combination of HRV analysis with mental workload measurement and outcome assessments provided the important clinical value in evaluating the effects of SS in VR applications in medical education.

Introduction: Efficacious screening of severe obstructive sleep apnea (OSA) is important for children with sleep-disordered breathing before time-consuming nocturnal polysomnography. However, the predictive performance of clinical variables, nocturnal unattended pulse oximetry, and snoring sound analysis to screen for severe pediatric OSA has not been comprehensively investigated. Methods: Forty-two consecutive children (11 [26%] girls and 31 [74%] boys; median age, 9 years; median body-mass index of 19.0 kg/m2) with loud snoring were prospectively recruited to undergo standard polysomnography, nocturnal pulse oximetry, and snoring sound analysis. Results: Binary logistic regression models showed that oxygen desaturation index ≥ 3% (> 5.9 events/h), adenoidal‐nasopharyngeal ratio (> 0.782), snoring sound energy of 801-1000 Hz (> 22.1 dB), and tonsil size (> 3) significantly predicted severe OSA, in descending order of odds ratio. Multivariate analysis showed that oxygen desaturation index ≥ 3%, adenoidal‐nasopharyngeal ratio, and tonsil size independently predicted severe OSA, and that their combination best predicted severe OSA (sensitivity = 91%; specificity = 84%; area under the curve = 0.92; p < 0.001). Conclusions: Our results suggested that pulse oximetry is better than snoring sound analysis to screen for severe OSA in children with loud snoring. A combination of oxygen desaturation index ≥ 3%, adenoidal‐nasopharyngeal ratio, and tonsil size can be used to efficiently screen for severe pediatric OSA.

Seizure is a common complication in a neurological intensive care unit (NICU) and it requires continuous electroencephalograms (EEG) monitoring. Implementation of EEG for each bed in a NICU is very expensive and require labor work for interpretation of EEG. To provide an affordable device of EEG in NICU, we developed a low-cost wireless biosensor, which utilized the current standard of the internet of things technology (IoT). In this study, we implement a wireless biosensor for continuous EEG monitoring in NICU and discuss its feasibility. To provide a low-cost EEG device, we embraced Bluetooth and mobile phone technology, which is convenient for implementation. We build a two-channel EEG biosensor, which utilizes Bluetooth to transmit the signal to mobile phones. Then, mobile phones use Wi-Fi technology to send data to the server. Additionally, we also developed a registry to organize the patient's EEG data. In six months research period, we have 65.8% of patients collected successfully. Using 2 channel-biosensor in NCU is feasible. It also develops a neuromedical database by collecting and monitoring physiological signals to develop future neuromedical research.

Pacemaker cells can be differentiated from stem cells or transdifferentiated from quiescent mature cardiac cells via genetic manipulation. Here we show that the exposure of rat quiescent ventricular cardiomyocytes to a silk-fibroin hydrogel activates the direct conversion of the quiescent cardiomyocytes to pacemaker cardiomyocytes by inducing the ectopic expression of the vascular endothelial cell-adhesion glycoprotein cadherin. The silk-fibroin-induced pacemaker cells exhibited functional and morphological features of genuine sinoatrial-node cardiomyocytes in vitro, and pacemaker cells generated via the injection of silk fibroin in the left ventricles of rats functioned as a surrogate in situ sinoatrial node. Biomaterials with suitable surface structure, mechanics and biochemistry could facilitate the scalable production of biological pacemakers for human use.

BACKGROUND Learning through a 360° virtual reality (VR) or 2D video represents an alternative way to learn a complex medical education task. However, there is currently no consensus on how best to assess the effects of different learning materials on cognitive load estimates, heart rate variability (HRV), outcomes, and experience in learning history taking and physical examination (H&P) skills. OBJECTIVE The aim of this study was to investigate how learning materials (ie, VR or 2D video) impact learning outcomes and experience through changes in cognitive load estimates and HRV for learning H&P skills. METHODS This pilot system–design study included 32 undergraduate medical students at an academic teaching hospital. The students were randomly assigned, with a 1:1 allocation, to a 360° VR video group or a 2D video group, matched by age, sex, and cognitive style. The contents of both videos were different with regard to visual angle and self-determination. Learning outcomes were evaluated using the Milestone reporting form. Subjective and objective cognitive loads were estimated using the Paas Cognitive Load Scale, the National Aeronautics and Space Administration Task Load Index, and secondary-task reaction time. Cardiac autonomic function was assessed using HRV measurements. Learning experience was assessed using the AttrakDiff2 questionnaire and qualitative feedback. Statistical significance was accepted at a two-sided P value of RESULTS All 32 participants received the intended intervention. The sample consisted of 20 (63%) males and 12 (38%) females, with a median age of 24 (IQR 23-25) years. The 360° VR video group seemed to have a higher Milestone level than the 2D video group (P=.04). The reaction time at the 10th minute in the 360° VR video group was significantly higher than that in the 2D video group (PP=.001) and a Milestone level of ≥3 (exp B=15.0, 95% CI 2.3-99.6; P=.005). However, a reaction time at the 10th minute of ≥3.6 seconds was not related to a Milestone level of ≥3. A low-frequency to high-frequency ratio between the 5th and 10th minute of ≥1.43 seemed to be inversely associated with a hedonic stimulation score of ≥2.0 (exp B=0.14, 95% CI 0.03-0.68; P=.015) after adjusting for video module. The main qualitative feedback indicated that the 360° VR video module was fun but caused mild dizziness, whereas the 2D video module was easy to follow but tedious. CONCLUSIONS Our preliminary results showed that 360° VR video learning may be associated with a better Milestone level than 2D video learning, and that this did not seem to be related to cognitive load estimates or HRV indexes in the novice learners. Of note, an increase in sympathovagal balance may have been associated with a lower hedonic stimulation score, which may have met the learners’ needs and prompted learning through the different video modules. CLINICALTRIAL ClinicalTrials.gov NCT03501641; https://clinicaltrials.gov/ct2/show/NCT03501641

Obstructive Sleep Apnea (OSA) has been proven to increase the risk of high blood pressure, heart attack, stroke, obesity, and diabetes. If people would like to know whether they are suffering from this sleep disorder, they need to go to particular hospital with which a sleep center that could perform polysomnography (PSG); however, for most people, this is not convenient. Consequently, the goal of this study is to develop a convenient, lower priced, and easy-to-use home-based sleep monitoring system. The researchers have developed the "Sleep Healthcare Management System" for OSA patients and healthcare providers. It combines smartphone and wearable devices that can perform real-time sleep monitoring. Healthcare providers could apply their professional knowledge to provide customized feedback via a web application. When the patient is diagnosed with an abnormal sleep health condition, healthcare providers may be able to provide appropriate and timely care.

To explore whether depth of sleep is related to changes in autonomic control, continuous power-spectral analysis of the electroencephalogram (EEG) and heart rate variability (HRV) was performed in ten normal subjects during nocturnal sleep. Quiet sleep (QS) was associated with an increase in high-frequency power (HF) of HRV (0.15-0.4 Hz) but a decrease in low-frequency power (LF) (0.04-0.15 Hz) to HF ratio (LF/HF) compared with awakening. During QS, LF/HF was significantly and negatively correlated with delta power of EEG (0.5-4.0 Hz), whereas mean R-R interval and HF were not. We conclude that during QS, cardiac sympathetic regulation is negatively related to the depth of sleep, although vagal regulation is not. Our methodology offers a quantitative analysis to study the interaction between cerebral cortical and autonomic functions.

BACKGROUND: Season of birth (SOB) has been found to be related to cardiovascular mortality, but the mechanisms are unclear. It is suggested that birth in winter is a protective factor for the circulatory system, and this should be able to be observed using heart rate variability (HRV) measurements. The phenomenon may have a sex difference and is likely to be modulated by climatic factors. This study focused on this problem and investigates healthy school‐age children to minimize confounding factors. HYPOTHESIS: Birth in winter is protective to cardiovascular system via autonomic modulation. There is a gender difference in the relationship between SOB and autonomic activity. Climatic factors are the cause of SOB effects on autonomic system. METHODS: A total of 381 healthy school‐age children were recruited for this study. Their HRV profiles were measured once and climatic information related to their month of birth was gathered. The HRV profiles of the 2 sexes and 4 seasons of birth were compared. Correlation and regression analysis were performed to clarify the relationship between climatic factors and the HRV results. RESULTS: Boys born in winter have higher high‐frequency power (HF) but a lower ratio of low‐frequency power to high‐frequency power (LF/HF) than do males born in other seasons. This result is not found for girls. Age and the temperature of the SOB are predictive factors for HF among boys. The humidity of SOB is a predictive factor for normalized low‐frequency power (LF%) and LF/HF among girls. CONCLUSIONS: Season of birth is related to both parasympathetic and sympathetic activity among school‐age children, especially boys. Temperature and humidity are potential causes of this SOB phenomenon.

Fourteen self-reported insomniacs (SRI) and 14 good sleepers (GS) had their cardiac neuronal activity assessed by heart rate variability (HRV) under controlled respiration at a slow frequency rate of 0.1 Hz, and a forced rate of 0.2 Hz during daytime rest. Nighttime sleep was measured by polysomnography. The SRI showed depressed high frequency power of HRV compared to the GS. An increased total power of HRV was observed among the SRI during slow, paced breathing compared with spontaneous breathing and 0.2 Hz. Sleep onset latency, number of awakenings, and awakening time during sleep were decreased and sleep efficiency was increased if SRI practiced slow, paced breathing exercises for 20 min before going to sleep. Our results indicate that there is autonomic dysfunction among insomniacs, especially in relation to vagal activity; however, this decreased vagal activity can be facilitated by practicing slow, paced breathing, thereby improving sleep quality.

Decreased heart rate variability (HRV) has been proposed in bipolar disorder. To date, there has been no adequate study that has investigated resting HRV in unmedicated patients with bipolar disorder in the manic state.To examine whether bipolar mania is associated with decreased HRV, 61 unmedicated patients with bipolar mania and 183 healthy volunteers aged 20-65 years were recruited for this case-control analysis. The Young Mania Rating Scale (YMRS), Clinical Global Impression-Severity, Hamilton Depression Rating Scale (HAM-D), and Hamilton Anxiety Rating Scale (HAM-A) were used for the clinical ratings. Cardiac autonomic function was evaluated by measuring HRV parameters and the frequency-domain indices of HRV were obtained.Patients with bipolar mania exhibited significantly lower mean RR interval, variance, low-frequency (LF)-HRV, and high-frequency (HF)-HRV but higher LF/HF compared to controls. Decreased HRV (variance) was associated with the YMRS total scores. Both the YMRS total scores and the Clinical Global Impression-Severity scores were positively correlated with the LH/HF ratio and inversely correlated with the HF-HRV. There was no significant correlation between the HAM-D/HAM-A scores and any HRV parameter.Bipolar mania is associated with cardiac autonomic dysregulation, highlighting the importance of assessing HRV in manic patients. Further studies examining the influence of anti-manic psychotropic drugs on cardiac autonomic regulation in bipolar mania are needed.

Medical internship is known to be a time of high stress and long working hours, which increases the risk of depression and cardiovascular disease. Gender differences in medical interns' cardiovascular risk have not been reported previously. Thirty-eight medical interns (29 males) were repeatedly tested for depressive symptoms using the Hospital Anxiety and Depression Scale and 5-min spectral analysis of heart rate variability (HRV) at 3-month intervals during their internship. Among the male interns, the variance of the heart rate decreased at 6, 9, 12 months, and a reduced high frequency, which suggests reduced cardiac parasympathetic modulation, was found at 9 and 12 months into their internship. Increased depressive symptoms were also identified at 12 months in the male group. No significant differences in depression or any of the HRV indices were identified among the female interns during their internship.

We proposed that the higher incidence of sleep fragmentation, sympathovagal imbalance and baroreceptor reflex impairment during quiet sleep may play a critical role in late-sleep-related cardiovascular events. Polysomnographic recording was performed through wireless transmission using freely moving Wistar-Kyoto rats over 24 h. The low-frequency power of arterial pressure variability was quantified to provide an index of vascular sympathetic activity. Spontaneous baroreflex sensitivity was assessed by slope of arterial pressure-RR linear regression. As compared with early-light period (Zeitgeber time 0-6 h), rats during the late-light period (Zeitgeber time 6-12 h) showed lower accumulated quiet sleep time and higher paradoxical sleep time; furthermore, during quiet sleep, the rats showed a lower δ% of electroencephalogram, more incidents of interruptions, higher σ% and higher β% of electroencephalogram, raised low-frequency power of arterial pressure variability value and lower baroreflex sensitivity parameters. During the light period, low-frequency power of arterial pressure variability during quiet sleep had a negative correlation with accumulated quiet sleep time and δ% of electroencephalogram, while it also had a positive correlation with σ% and β% of electroencephalogram and interruption events. However, late-sleep-related raised sympathetic activity and sleep fragmentation diminished when an α1-adrenoceptor antagonist was given to the rats. Our results suggest that the higher incidence of sleep fragmentation and sympathovagal imbalance during quiet sleep may play a critical role in late-sleep-related cardiovascular events. Such sleep fragmentation is coincident with an impairment of baroreflex sensitivity, and is mediated via α1-adernoceptors.

Repetitive transcranial magnetic stimulation (rTMS) has been reported to be an effective treatment for auditory hallucination (AH) in schizophrenia patients. The efficacy of rTMS and immediate changes in cardiac autonomic function (CAF) after rTMS in severe schizophrenia patients with AH (n = 8) were investigated. Three patients reported aor=50% reduction of AH after rTMS. The ratio of low-frequency power to high-frequency power, an index of sympathetic modulation, increased significantly after rTMS. Further replication studies with larger sample sizes are indicated.

Forearm cutaneous perfusion is an established in vivo model in many clinical and basic researches to explore the peripheral circulation. The aim of our study is to characterize the dynamic properties of regional microcirculation after simultaneous denervation and revascularization in free forearm flap transplantations. Serial changes in laser Doppler flow and cutaneous temperature were measured during 14 forearm flap transplantations. Digitalized perfusion data were relayed for power spectral analysis based on the fast Fourier transform. Real time heart rate variability was measured to verify the influence of systemic autonomic nervous modulations. The basal flow expressed a threefold to fourfold increase, from 20.31 +/- 3.25 to 73.79 +/- 11.78 PU, after the transplantation. Frequency domain analysis of cutaneous blood flow variability showed significantly increased high frequency (0.15-0.4 Hz, 55.14% +/- 3.31% to 65.31% +/- 2.78%, P = 0.0035) and decreased very low frequency (0.003-0.04 Hz, 18.61% +/- 2.70% to 9.25% +/- 1.38%, P = 0.0049) power fraction after flap transfer. Simultaneous denervation and revascularization of forearm flaps increased the regional blood flow significantly that was caused by increased high frequency and decreased very low frequency fractional contributions in dynamic regulation of regional cutaneous microcirculation. They are associated with the sympathetic denervation and reactive hyperemia, respectively.

Several studies have reported that the experience may induce emotional reactions before and after surgery. Various Studies have demonstrated that effective pre-operative information reduces stress and anxiety levels. However, little is known about the effect of pre-operative instruction on autonomic responses as measured by heart rate variability (HRV) before cardiac surgery. Ninety-one patients were randomly assigned to video-tape viewing and teaching booklet group. Electrocardiogram was monitored before and after pre-operative instruction. HRV was analyzed with spectral analysis of frequency domains of heart rate and categorized into low and high frequency (LF and HF). After pre-operative instruction, subjects completed a score of perceived stress and helpfulness. In this study, we found that pre-operative instruction with video-tape was similarly effective as teaching booklets on patients' perceived stress, perceived helpfulness and recovery outcomes. The decrease in HF% and increase in LF/HF ratio of HRV indicate a change in sympathovagal balance toward a lower parasympathetic activity after pre-operative instruction in subjects of both groups. However, the perceived helpfulness of pre-operative instruction may often be associated with a relatively less sympathetic activity. Further studies are needed to determine the optimal timing to enhance the positive effects on the sympathovagal balance after pre-operative instruction.