老年冠心病患者腹腔镜胆囊切除术中CO2气腹对心率变异性的影响及星状神经节阻滞对气腹的干预作用

【目的】观察老年冠心病患者在腹腔镜胆囊切除术（TVLC）中CO2气腹对心率变异性的影响以及术前经右侧星状神经节阻滞对CO2气腹的干预作用。【方法】选择2008年5月至2008年12月择期在全麻下行TVLC的老年冠心病患者60例。随机分为两组,对照组和右侧星状神经节阻滞组（R-SGB组）各30例。分别于麻醉后SGB前（T0）、SGB后（T1）、气腹后10min（T2）、20min（T3）和30min（T4）记录HR、MAP并分析患者的心率变异性（heart rate variability,HRV）。HRV通过功率谱分析：低频率（LF）,高频率（HF）,LF／HF比率,总能量（TP）。【结果】CO2气腹后老年冠心病患者LF、LF／HF、TP均升高（P〈0．05）。R-SGB组气腹后各时点LF、LF／HF、TP升高低于对照组（P〈0．05）。两组HF未见明显改变（P〉0．05）。【结论】CO2气腹使老年冠心病患者交感神经活性显著升高,右侧星状神经节阻滞可减轻CO2气腹时的心血管反应,维持CO2气腹时的交感／迷走神经张力的均衡。     

Heart rate variability in patients presenting with neurally mediated syncope in an emergency department

BackgroundNeurally mediated syncope (NMS) is a disorder of autonomic nervous system (ANS) regulation. Orthostatic stress is one of the most common causative factors seen in clinical practice. Analysis of heart rate variability (HRV) is a non-invasive method that is used to assess ANS regulation. In this study, we investigated the pathophysiology of NMS using HRV in our emergency department.MethodsThe subjects were 19 patients (age 25.8 ± 6.2 years old) who presented with NMS and 20 healthy individuals (age 26.6 ± 2.7 years old) who served as controls. HRV was measured in supine, sitting and standing positions. Heart rate (HR), low frequency (LF 0.04–0.15 Hz), high frequency (HF > 0.15 Hz), and coefficient of variation of the R-R interval (CVRR) were determined.ResultsLF and HF in the supine position were significantly lower in the patients with NMS (p < 0.05). HR was higher in all positions in patients with NMS than in healthy individuals (p < 0.05). CVRR in the supine position was lower in the patients with NMS (p < 0.001), and it was significantly lower in patients who were positive in an orthostatic test (p = 0.0017). Area under the curve was calculated to be 0.824, and at the cutoff value of 4.997 of CVRR in supine, the sensitivity and the specificity were 78.9% and 85.0%.ConclusionThe sympathetic and parasympathetic nervous systems were both suppressed in patients with NMS. In post-syncope, parasympathetic withdrawal, rather than sympathetic reactivation, was responsible for the increased HR after syncope. CVRR may serve as a new clinical biomarker in the emergency department.     

Day-to-night time differences in the relationship between cardiorespiratory coordination and heart rate variability

Heart rate variability (HRV) and cardiorespiratory coordination, i.e. the temporal interplay between oscillations of heartbeat and respiration, reflect information related to the cardiovascular and autonomic nervous system. The purpose of this study was to investigate the relationship between spectral measures of HRV and measures of cardiorespiratory coordination. In 127 subjects from a normal population a 24 h Holter ECG was recorded. Average heart rate (HR) and the following HRV parameters were calculated: very low (VLF), low (LF) and high frequency (HF) oscillations and LF/HF. Cardiorespiratory coordination was quantified using average respiratory rate (RespR), the ratio of heart rate and respiratory rate (HRR), the phase coordination ratio (PCR) and the extent of cardiorespiratory coordination (PP). Pearson's correlation coefficient r was used to quantify the relationship between each pair of the variables across all subjects. HR and HRR correlated strongest during daytime (r = 0.89). LF/HF and PP showed a negative correlation to a reasonable degree (r = -0.69). During nighttime sleep these correlations decreased whereas the correlation between HRR and RespR (r = -0.47) as well as between HRR and PCR (r = 0.73) increased substantially. In conclusion, HRR and PCR deliver considerably different information compared to HRV measures whereas PP is partially linked reciprocally to LF/HF.     

不同体位和阻力运动对健康人心血管反应的影响

目的：通过在坐位和卧位两种不同体位下,观察健康人进行不同强度抗阻运动时心血管反应及主观感受水平的变化.方法：20名观察对象随机采取坐位、卧位,轻、重两种弹性阻力下,进行每组5min,共4组的右侧伸膝抗阻运动的间歇性运动训练,静止期及每次运动前后均采集观察对象的心率、血压和心率变异性、自觉疲劳程度和焦虑水平等指标.结果：不同体位下的心率（HR）、低频与高频的比值（LF/HF）、高频功率（HFms2）、标准化低频功率（LFn.u.）和标准化高频功率（HFn.u.）差异有统计学意义（P＜0.01）,在体位与阻力的交互作用下这几个指标差异也有统计学差异（P＜0.01）,不同阻力间HR差异有统计学差异（P＜0.01）.卧位下两级阻力间HR差异有统计学差异（P＜0.01）.结论：实验结果提示,体位对心血管反应的影响较明显,而轻阻力负荷下,其阻力差引起的心血管反应差异不明显.各项客观指标对于训练过程中机体的变化灵敏性高于主观感受指标.     

Depressed heart rate variability is associated with high IL-6 blood level and decline in the blood pressure in septic patients

Depressed heart rate variability (HRV) in septic patients is known to be associated with poor outcome. However, neither etiology of depression of HRV nor its clinical significance has been clearly determined. Because hypercytokinemia plays an important role in sepsis, we investigated the relationships between depressed HRV and IL-6 blood level. The subjects of this study were 45 septic patients treated in our intensive care unit. IL-6 blood level upon admission exhibited significant negative correlations with two HRV indices, low-frequency power (LF) (r = -0.76; P < 0.01) and high-frequency power (HF) (r = -0.53; P < 0.01). Multivariate analysis revealed strong correlations between IL-6 blood level and LF (P = 0.01) and HF (P = 0.01), respectively, even when the effects of patient background factors and therapeutic intervention were taken into account. Among the patients who developed septic shock, a high IL-6 blood level and a low LF were observed in both the survivor and nonsurvivor groups on the day of admission. The HF was lower than normal at the same time points in both groups. However, the HF was significantly higher in the nonsurvivor group than in the survivor group. By the time of discharge from the intensive care unit, both IL-6 blood level and HRV indices had become significantly closer to the normal ranges in the survivor group, but not in the nonsurvivor group. A significant negative correlation was observed between LF upon admission and percent decline in blood pressure (r = -0.76, P < 0.01). These findings indicate that reduction in HRV indices is associated with hypercytokinemia, indicating that the autonomic nervous system and the inflammatory response mediated by the cytokine network affect each other. These results also suggest that depression of HRV is closely related to rapid changes in blood pressure. Thus, heart rate variability indices are associated with both the severity and poor outcome of sepsis.     

Assessment of autonomic nervous system functions in patients with vitamin B12 deficiency by power spectral analysis of heart rate variability

The purpose of this study was to test the autonomic nervous system function of patients with vitamin B12 deficiency (megaloblastic anemia) by measuring heart rate variability (HRV). The study population consisted of 17 vitamin B12 deficient patients and 15 age- and sex-matched normal volunteers. HRV was measured by power spectral analysis from which power of the low frequency (LF) peak (0.04-0.15 Hz), normalized units of the LF peak (LFNU), power of the high frequency (HF) peak (0.15-0.4 Hz), normalized units of the HF (HFNU), and ratio of power of LF to power of HF (LF:HF) were calculated. Vitamin B12 deficient patients had lower LF, LFNU, HF, HFNU, and LF:HF ratio than normal volunteers (P < 0.05). Decreases in sympathetic indices (LF and LFNU) were greater than those measured in parasympathetic indices (HF and HFNU). All HRV parameters correlated positively with the level of vitamin B12 (P < 0.001) and negatively with the duration of disease (P < 0.001). After vitamin B12 replacement the HRV parameters of patients and controls became comparable (P > 0.05). Our data suggest that autonomic sympathetic and parasympathetic nervous activities are decreased in patients with vitamin B12 deficiency, an abnormality that can be corrected by vitamin B12 replacement therapy.     

异丙酚和七氟烷麻醉对心率变异性的不同影响

目的 观察异丙酚和七氟烷麻醉对心率变异性的不同影响.方法 选择择期行妇科腹腔镜手术病人40例,随机分为两组,异丙酚组（P组,20例）术中以异丙酚麻醉维持,七氟烷组（S组,20例）术中以七氟烷麻醉维持.记录麻醉前、麻醉诱导后、插管后、切皮后、气腹形成后、关气腹、拔管后10min七个时点的心率（HR）、平均动脉压（MAP）、BIS和低频（LF）、高频（HF）、低高频比值（LF/HF）、心率变异指数（HRV）等心率变异性指标.结果 麻醉诱导后两组病人的HR、MAP、BIS、HRV、HF、LF、LF/HF均显著性下降（ P〈0.05）,两组间无显著差异.在麻醉维持过程中P组LF值显著降低,HF值不降低甚至略有升高,LF/HF值显著下降;S组LF及HF均显著降低,与P组相比LF降低更明显（ P〈0.05）,S组LF/HF值无明显变化,与P组有显著性差异（ P〈0.05）.结论 异丙酚对交感神经系统抑制明显,异丙酚麻醉自主神经系统向副交感神经占优势的方向转变;七氟烷对迷走神经系统和交感神经系统均有抑制,对自主神经系统的平衡性无明显影响.     

Relationship Between Short- and Long-Term Measurements of Heart Rate Variahility in Patients at Risk of Sudden Cardiac Death

Because of technical difficulties in analyzing heart rate variability (HRV) from ambulatory Holter recordings over 24-hour periods, short-term recordings are more practical for the clinical application of HRV. However, the relationship between short- and long-term recordings is unclear. In this study, short-term (10 min) electrocardiograms were assessed in the supine position, during passive head-up tilt and on standing in 15 patients (aged 39 ± 14 years) with ventricular tachycardia/fibrillation not associated with coronary artery disease. Spectral HBV was computed as total frequency (TF: 0.01–1.00 Hz), low frequency (LF: 0.04–0.15 Hz), and high frequency (HF: 0.15–0.40 Hz) components. The short-term HRV parameters were compared with those obtained from long-term (24 hour) recordings from the same patients. There was a significant decrease in the HF component of HRV and a significant increase in LF/HF ratio during passive tilt or active standing compared with supine recordings, but no significant changes were observed in the TF or LF components. All frequency components of HRV for the 24-hour periods showed significant correlation with the values from short-term recordings (τ ranged from 0.67–0.87). Stepwise multivariate regression analysis showed that both the TF and HF components of HRV over 24 hours were predominantly related to the corresponding frequency components of HBV in the supine position, while the LF component of HRV over 24 hours was predominantly related to that on standing. Our observations suggest that the short-term HRV is related to the long-term value, but global HRV over 24 hours cannot completely be replaced by the short-term recordings. The postural effects on the frequency components of HRV should be taken into account when short-term HRV assessment is applied.     

Heart rate variability following neonatal heart surgery for complex congenital heart disease

BACKGROUND: Altered cardiac autonomic control may play a role in the morbidity and mortality suffered by neonates who undergo surgery for complex congenital heart disease (CHD). The purpose of this study was to evaluate cardiac autonomic activity, as measured by spectral indices of heart rate variability (HRV), prior to and early after infant surgery for CHD and attempt to correlate HRV indices with clinical outcome. In addition, we assessed the hypothesis that single-ventricle physiology and surgical interruption of the great arteries negatively affects HRV. METHODS: Sixty neonates prospectively wore 24-hour Holter monitors at three time points: before and early after CHD surgery, and at 3- to 6-month follow-up. Standard spectral indices of HRV were measured. RESULTS: In the early postoperative time point, patients with single-ventricle physiology had lower low-frequency power (LF) compared to patients with two ventricles (P=0.040). Surgical interruption of the great arteries did not affect HRV in this cohort. For the entire cohort, LF (P=0.004) and high-frequency power (HF) (P<0.001) increased over the three time points, while LF/HF (P=0.119) did not significantly change. In the multivariable linear regression model, significant predictors of longer postoperative hospital stay included longer total support time (P=or<0.001), longer duration of inotrope support (P=0.012), elevated mean heart rate at postoperative time point (P=0.002), and lower LF/HF ratio at the postoperative time point (P=0.014). CONCLUSION: Patients with single-ventricle physiology have a significant physiologic reduction in LF in the early postoperative period compared to patients with two ventricles. Diminished cardiac autonomic control is associated with longer hospitalization following neonatal cardiac surgery.     

Short- and long-term reproducibility of autonomic measures in supine and standing positions

Autonomic nervous tests and heart rate variability (HRV) have been used to assess cardiac autonomic function and to evaluate long-term prognosis. The aim of this study was to evaluate the short- and long-term reproducibility of HRV parameters and autonomic nervous tests according to body position (supine or standing). The study group consisted of 26 healthy subjects. Autonomic nervous tests and HRV were performed twice during the day and the results were averaged. The protocol was then repeated 3 days after each examination and also after 6 and 24 months. Autonomic nervous tests included deep breathing, Valsalva manoeuvre and isometric muscle exercise (handgrip), as well as blood pressure and heart rate in response to standing. ECG recordings were taken for 10 min during spontaneous breathing for HRV analysis. We found that the reproducibility of some parameters of the autonomic nervous test were independent of body position [E/I ratio (heart rate response to deep breathing)], whereas other parameters were dependent on body position (Valsalva manoeuvre and blood pressure response to sustained handgrip). In addition, within-day measurements of those parameters varied from non-reproducible (Valsalva ratio, handgrip and blood pressure response to standing) to moderately reproducible [E/I ratio and 30/15 ratio (heart rate response to standing)]. Among the HRV parameters, we found that total power (TP), low (LF)- and high (HF)-frequency were reproducible not only for measurements made within the same day, but also during short- and long-term observations, and only the LF/HF ratio was dependent on body position. We conclude that only a few autonomic nervous tests are reproducible in the short- and long-term. Because HRV parameters obtained during spontaneous respiration showed high reproducibility for measurements made within the same day as well as in the short- and long-term, they should be used instead of autonomic nervous tests when long-term observations are carried out in a healthy population.     

Heart rate variability after acute traumatic brain injury in children

OBJECTIVE: To evaluate heart rate variability (HRV) by power spectral analysis of heart rate and its relationship to intracranial pressure (ICP), cerebral perfusion pressure (CPP), and outcomes in children with acute traumatic head injury. DESIGN: Prospective, case series. SETTING: Pediatric intensive care unit in a level II trauma center/children's hospital. SUBJECTS: Fifteen critically ill children with documented acute traumatic brain injury and four control subjects. INTERVENTIONS: None. MEASUREMENTS AND MAIN RESULTS: The normalized total power from 0.04 to 0.15 Hz was used to quantify low-frequency HRV and from 0.15 to 0.40 Hz to quantify high-frequency HRV. The ratio of low- to high-frequency (LF/HF) power was used as a measure of sympathetic modulation of heart rate. The power spectral data from the 5-min samples were averaged over each hour of data collection, and an hourly LF/HF ratio was obtained based on a 60-min electrocardiogram collection (twelve 5-min segments). The daily mean LF/HF ratio was calculated from the hourly LF/HF measurements. We found no linear correlation between the LF/HF ratio and either ICP or CPP (p = NS). There was a significant decrease in the LF/HF ratio when the intracranial pressure was >30 mm Hg (p < .001) or the cerebral perfusion pressure was <40 mm Hg (p < .001). Children with a Glasgow Coma Scale score of 3-4 had a lower LF/HF ratio compared with those who had a Glasgow Coma Scale score of 5-8 (p < .005). Patients who progressed to brain death had a markedly lower LF/HF ratio (p < .001), with a significant decrease after the first 4 hrs of hospitalization. Patients with more favorable outcomes had significantly higher LF/HF ratios. CONCLUSIONS: Our findings suggest that an ICP of >30 mm Hg or a CPP of <40 mm Hg may be associated with marked autonomic dysfunction and poor outcome. We speculate that HRV power spectral analysis may be a useful adjunct in determining the severity of neurologic insult and the prognosis for recovery in children. The LF/HF ratio may be helpful not only in identifying those patients who will progress to brain death but also in predicting which patients will have favorable outcomes.     

Effects of 50 Hz magnetic field exposure on human heart rate variability with passive tilting

The question of whether power-frequency magnetic fields of strengths relevant to industrial exposure can affect heart rhythm remains controversial. Because the reported effects on heart rate (HR) are so small, procedures which can provoke changes in the sympathovagal balance in a controlled manner may have a greater capacity for identifying subtle field-related changes, if they do exist. We have investigated HR and heart rate variability (HRV) spectral indices in 20 volunteers subjected to a tilt from the supine position to 60 degrees , head up. The tilting procedure was carried out under two conditions, field (28 microT resultant, circularly polarized) and sham, in a balanced double-blind design. Subjects were instructed to breathe in time with an audible cue at 2.5 s intervals. Although the anticipated significant changes in HR and the high frequency (HF), low frequency (LF) and LF/HF ratio (log transformed) occur with tilting, there were no significant differences between corresponding measures with and without exposure to magnetic fields (tilt ln LF/HF ratio 0.94 +/- 0.19 and 0.95 +/- 0.20 for sham and field, respectively). There was also no evidence of a field-related trend in spectral alterations when the time following tilting was divided into three 256 s epochs.     

Association of estrogen receptor-α gene polymorphisms with cardiac autonomic nervous activity in healthy young Japanese males

BackgroundEstrogens exert beneficial effects on the cardiovascular system that are mediated by estrogen receptors. We examined the association between the estrogen receptor α gene (ESR1) PvuII and XbaI polymorphisms and cardiac autonomic nervous function in Japanese males.MethodsWe examined 252 young healthy males for association of ESR1 PvuII and XbaI polymorphisms and short-term heart rate variability (HRV) during supine rest and in a standing position. The very low frequency (VLF), low frequency (LF), and high frequency (HF) components of HRV were quantified by frequency domain analysis.ResultsCarriers of the ESR1 PvuII C allele had higher mean blood pressure (BP), while the XbaI GG genotype was significantly associated with higher diastolic and mean BP, but lower HR. In the haplotype analysis, carriers of the ESR1 haplotype 2 (PvuII C and XbaI A) allele had a higher systolic and mean BP, and lower HRV spectral powers (total power, VLF, LF, and HF components) in a supine rest compared with those of non-carriers.ConclusionsThe ESR1 PvuII and XbaI haplotype is associated with BP variation and the reduction in cardiac autonomic nervous activity in young Japanese males, which may be precursors of future pathological episodes of cardiovascular diseases.     

Heart rate variability and autonomic nervous system changes in children with vasovagal syncope

The aim of this study was to evaluate the HRV at rest and during tilt test (HUTT) in children with a history of vasovagal syncope and to link the HRV indices with the clinical results of the test. HRV indices were assessed in the supine position and during the initial 5 minutes of the 60-degree HUTT in 49 patients (33 females, 16 males, mean age of 13 +/- 2.8 years) who were evaluated for recurrent syncope. The positive to negative results of the test were 21 to 28. The normalized power of high frequency component (npHF) decreased, normalized power of low frequency component (npLF) and the LF:HF ratio increased during HUTT of tilt-positive patients (P < 0.05 for each parameter). Parallel changes, but to a lesser degree, were observed for similar HRV parameters of tilt-negative patients. In addition, the HF and all the time-domain indices decreased significantly (P < or = 0.05) during HUTT in the latter group. When the tilt-positive and -negative patients were compared, the npHF was lower (P = 0.002), npLF and LF:HF ratio were higher (P = 0.01 and P = 0.001, respectively) during the test in tilt-positive patients, reflecting increased sympathetic tone in this group. A cut-off point for LF:HF was assigned as 2.7 for differentiating tilt-negative and tilt-positive results. The specificity, sensitivity, and positive and negative predictive values of this cut-off point were calculated as 93%, 52%, 85%, and 41%, respectively. Patients with vasovagal syncope show variations in vagal autonomic tone and appear to be more prone to syncope when their sympathetic tone is elevated at the beginning of the test. LF:HF > 2.7 is a specific marker (specificity 93%) and can correctly predict a positive tilt test in 85% of patients.     

4-aminopyridine influences heart rate variability in long-standing spinal cord injury.

Humans with traumatic spinal myelopathy exhibit intralesional conduction block and autonomic failure as pathophysiologic sequelae of their injury. Analysis of heart rate variability (HRV) provides a means of assessing changes in the function of the autonomic nervous system (ANS) and the cardiac sequelae of injury. Thirteen patients with long-standing spinal cord injury (SCI) and 13 able-bodied controls were studied. Each patient received a single 10-mg dose of an immediate release (IR) formulation of 4-aminopyridine (4-AP). Twenty-four hour heart rate (HR) and HRV data were acquired using a Holter ambulatory electrocardiographic (ECG) monitor. Analysis of acquired data was carried out using a minicomputer programmed to separate ECG R-R intervals into frequency patterns that appear as peaks dispersed along a frequency range of 0.0 to 1.0 Hz. Twenty-four hour baseline, pretreatment low-frequency (LF) HRV power was diminished in all patients with SCI compared with able-bodied-controls and was significantly decreased in tetraplegic patients (P = 0.03). This difference in LF HRV power disappeared during the 24 hours immediately after administration of 4-AP, and mean LF HRV power in tetraplegic patients became indistinguishable from LF HRV power in controls. 4-Aminopyridine appears to influence ANS function and LF HRV in humans with long-standing SCI.     

Heart rate variability in elite sprinters: effects of gender and body position

To describe the heart rate variability (HRV) of high‐level sprinters in both the supine and standing positions, the HRV of 7 male (24 ± 6 years; 80 ± 8 kg and 182 ± 7 cm) and 11 female (27 ± 5 years; 61 ± 4 kg; 167 ± 5 cm) high‐level Brazilian sprinters was measured in the standing and supine body positions in both the time and frequency domains. The heart rate (HR) and the time (SDNN, RMSSD) and frequency (LF; HF and LF:HF) domains of the HRV were assessed. Natural log‐transformations (ln) of all HRV indices were log‐transformed prior to analysis to reduce bias arising from non‐uniformity of error. The Cohen's effect size and magnitude‐based inference (MBI) were obtained for comparisons. The results suggest higher cardiac autonomic stress in the standing position than in the supine for both genders. With the exception of the lnSDNN that showed possibly MBI in female athletes, all other HRV indices presented a likely or almost certainly MBI. Male athletes demonstrated a higher lnSDNN in the supine body position (very likely MBI) and a higher HR in the standing position (very likely MBI) than females. In conclusion, elite sprinters (independent of the gender) present lower HRV in the standing position than in the supine position, but males present a more notable change in cardiac autonomic stress than female athletes.     

Effect of spontaneous saliva swallowing on short‐term heart rate variability (HRV) and reliability of HRV analysis

The effects of effortful swallowing and solid meal ingestions on heart rate variability (HRV) have been examined previously. The effects of spontaneous saliva swallowing on short‐term HRV and reliability of HRV analysis have not been studied before. The effect of saliva swallowing on HRV analyses parameters [meanRRI, SDNN (standard deviation of normal‐to‐normal), LF (low frequency), HF (high frequency) powers, LH/HF] and the reliability of LF and HF powers were investigated by frequency, time–frequency and intraclass correlation coefficient (ICC) analyses. Electrocardiogram and swallowing signal that obtained from an electronic stethoscope placed on the necks of subjects were recorded simultaneously from 30 healthy and young volunteers in sitting position during 15 min. Spontaneous swallowing has been shown to significantly alter some HRV parameters (SDNN, LF power and LF/HF ratio). Time‐frequency analysis results showed that the contribution of saliva swallowing to LF (1–58%) and HF (2–42%) powers could change significantly depending on the number of swallowing. The ICC of the LF and HF powers for the successive 5‐min signal segments were found 0·89, 0·92, respectively. These values decreased to 0·73 and 0·90 in the subjects with more swallowing rate. When the analyses were made for 2‐min signal periods, these values decreased to 0·63 and 0·67. We concluded that spontaneous saliva swallowing can change HRV parameters. We have also seen that changes in swallowing rate and use of short signal segments may reduce the reliability of HRV analyses.     

I-gel喉罩对全身麻醉患者心率变异的影响

目的观察I-gel喉罩对全麻患者心率变异性(HRV)的影响,评价I-gel喉罩在临床应用中的安全性和可行性。方法 40例拟行气管插管全麻患者,随机分为两组:传统气管插管组(C组)和I-gel喉罩插管组(E组),每组20例。观察诱导前(T0)、诱导后(T1)、插管即刻(T2)、插管后1 min(T3)、5 min(T4)的HRV及心率(HR)、收缩压(SBP)、舒张压(DBP)。结果与T1相比较,C组患者T2、T3相的HRV中的总频(TF)、低频(LF)和LF与HF比值(LF/HF)明显增加,C组增加程度大于E组(P0.05);C组相应时间点HR,SBP及DBP增加程度也明显大于E组(P0.05)。结论 I-gel喉罩对心率变异性干扰小,循环稳定,是一种安全有效的插管方法。     

左侧星状神经节麻醉阻滞对冠脉搭桥术患者心率变异性和交感神经活性的影响及临床意义

目的探讨左侧星状神经节阻滞(SGB)对冠脉搭桥术(CABG)患者心率变异性(HRV)和交感神经活性的影响。方法前瞻性将本溪市中心医院2016年1月至2018年6月间行择期CABG的80例患者采用随机数表法分为观察组和对照组,每组各40例。观察组予以SGB联合常规麻醉,对照组予以常规麻醉。评估两组麻醉前、诱导后、气管插管后、劈胸骨后、搭桥后循环指标[心率(HR)、平均动脉压(MAP)]、HRV水平[低频(LF)、高频(HF)],评估麻醉前、搭桥后交感神经活性[血管紧张素(AT-Ⅱ)、去甲肾上腺素(NE)],比较两组血管活性药物用量。结果①气管插管后、劈胸骨后、搭桥后,两组HR、MAP水平升高(P<0.05);观察组各个时间点HR、MAP变化较对照组小,组间比较差异具有统计学意义(P<0.05);②两组LF、HF水平均先降低后升高(P<0.05),组间差异无统计学意义(P>0.05),测量时间点与不同麻醉方案之间差异无统计学意义(P>0.05);③两组搭桥后AT-Ⅱ、NE水平均高于麻醉前(P<0.05),观察组增幅小于对照组(P<0.05);④两组盐酸多巴胺、盐酸多巴酚丁胺用量比较,差异无统计学意义(P>0.05)。结论左侧SGB联合常规麻醉有利于稳定CABG患者术中血流动力学,控制患者交感神经活性,且不引起HRV降低。     

腹腔镜手术对小儿心率变异性的影响

目的观察腹腔镜手术下小儿心率变异性（Heart rate variability，HRV）的变化，为小儿术中及术后心血管的康复提供依据。方法选择ASAⅠ或Ⅱ级择期行腹腔镜手术的患儿20例，全部采用静吸复合全麻，气管内插管，呼吸机行间歇正压通气。分别于麻醉前、气腹前、气腹5min、气腹20min、气腹30min和放气腹5min观察心率变异性指标总功率（TP）、高频功率（HF）、低频功率（LF）、低频标准化值（LFNU）、高频标准化值（HFNU）和低频高频功率比（LF／HF）的变化。结果与气腹前比较，TP、LF、LFNU和LF／HF显著升高（P〈0．01），Hk，无明显变化（P〉0．05）。结论腹腔镜手术气腹后小儿交感神经占优势。HRV可作为麻醉循环监测的敏感指标，动态反映小儿自主神经的变化。