Objective To investigate the changes and clinical relationship of plasma adrenomedullin( ADM) , atrial natriuretic polypeptide( ANP) , and heart rate variability( HRV) in patients with obstructive sleep apnea-hypopnea syndrome ( OSAHS) . Methods Seventy-five inpatients with OSAHS were enrolled in this study. According to the apnea hypopnea index ( AHI) by polysomnography, the subjects were divided into a mild group, a moderate group, and a severe group. Meanwhile, HRV was screened bydynamic electrocardiogram in sleep laboratory. HRV parameters were obtained including LF ( low frequency power) , HF( high frequency power) , pNN50( percentage of NN50 in the total number of N-N intervals) ,SDNN( standard deviation of the N-N intervals) , rMSSD( square root of the mean squared differences of successive N-N intervals ) . Plasma levels of ADM/ANP were measured by radioimmunoassay. Results The levels of SDNN ( P lt;0. 05) , rMSSD, pNN50, LF ( P lt; 0. 05) and HF were gradually reduced, and the levels of ADM ( P lt;0. 05) and ANP ( P lt; 0. 05) were increased with increasing severity of OSAHS. Linear correlation analysis demonstrated that SDNN was negatively correlated with ADM( r = - 0. 423, P lt;0. 05)and ANP( r = - 0. 452, P lt; 0. 05) , and LF was also negatively correlated with ADM( r = - 0. 348, P lt;0. 05) . Conclusion Lower HRV is associated with more sever OSAHS, and it may be modulated neurohumorally by ADM and ANP.
Objective To explore the best mode of blood pressure monitoring by comparing the correlation of deferent kinds of blood pressure variability with arterial stiffness. Methods This study was conducted among 140 hypertensive patients in Wuhou Strict, Chengdu. Baseline data was collected including demographic data, biochemical examination and brachial-ankle pulse wave velocity (baPWV) measurement and so on. A consecutive home blood pressure was also gained by the individuals themselves and the clinical blood pressure was also recorded during the visit. The correlation between baPWV and the blood pressure variability were tested. Results The blood pressure variability measured at home in the morning was independently correlated with baPWV (r=0.313, P=0.011), the blood pressure variability measured at home in the evening was also independently correlated with baPWV (r=0.241, P=0.042), and day-to-day morning blood pressure variability measured at home was correlated with baPWV (r= 0.269, P=0.030). The correlation of month-to-month blood pressure variability and blood pressure variability gained at clinic room with baPWV was not significant (P>0.05). Conclusion In the monitoring of blood pressure variability in hypertensive patients, the blood pressure variability monitoring at home is better than that at the clinic room; and monitoring in the morning is better than that in the evening.
ObjectiveTo study the relationship between preoperative heart rate variability (HRV) and postoperative atrial fibrillation (POAF) after off-pump coronary artery bypass grafting (OPCAB). MethodsA retrospective analysis was performed on the clinical data of 290 patients who were admitted to the Department of Cardiovascular Surgery, General Hospital of Northern Theater Command from May to September 2020 and received OPCAB. There were 217 males and 73 females aged 36-80 years. According to the incidence of POAF, the patients were divided into two groups: a non-atrial fibrillation group (208 patients) and an atrial fibrillation group (82 patients). The time domain and frequency domain factors of mean HRV 7 days before operation were calculated: standard deviation of all normal-to-normal intervals (SDNN), root mean square of successive differences, percentage difference between adjacent normal-to-normal intervals that were greater than 50 ms, low frequency power (LF), high frequency power (HF), LF/HF. ResultsThe HRV value of patients without POAF was significantly lower than that of patients with POAF (P<0.05). The median SDNN of the two groups were 78.90 ms and 91.55 ms, respectively. Age (OR=3.630, 95%CI 2.015-6.542, P<0.001), left atrial diameter (OR=1.074, 95%CI 1.000-1.155, P=0.046), and SDNN (OR=1.017, 95%CI 1.002-1.032, P=0.024) were independently associated with the risk of POPAF after OPCAB. Conclusion SDNN may be an independent predictor of POAF after OPCAB.
Lorenz plot (LP) method which gives a global view of long-time electrocardiogram signals, is an efficient simple visualization tool to analyze cardiac arrhythmias, and the morphologies and positions of the extracted attractors may reveal the underlying mechanisms of the onset and termination of arrhythmias. But automatic diagnosis is still impossible because it is lack of the method of extracting attractors by now. We presented here a methodology of attractor extraction and recognition based upon homogeneously statistical properties of the location parameters of scatter points in three dimensional LP (3DLP), which was constructed by three successive RR intervals as X, Y and Z axis in Cartesian coordinate system. Validation experiments were tested in a group of RR-interval time series and tags data with frequent unifocal premature complexes exported from a 24-hour Holter system. The results showed that this method had excellent effective not only on extraction of attractors, but also on automatic recognition of attractors by the location parameters such as the azimuth of the points peak frequency (APF) of eccentric attractors once stereographic projection of 3DLP along the space diagonal. Besides, APF was still a powerful index of differential diagnosis of atrial and ventricular extrasystole. Additional experiments proved that this method was also available on several other arrhythmias. Moreover, there were extremely relevant relationships between 3DLP and two dimensional LPs which indicate any conventional achievement of LPs could be implanted into 3DLP. It would have a broad application prospect to integrate this method into conventional long-time electrocardiogram monitoring and analysis system.
目的:了解阻塞性睡眠呼吸暂停综合征患者的心率变异改变。方法:对67例睡眠打鼾患者同步进行24小时动态心电图及多导睡眠图监测。根据PSG检测结果分为OSAS组和单纯鼾症组,比较组间低频峰(LF),高频峰(HF),低频峰与高频峰的比值(LF/HF),正常RR间期平均值及其标准差值(SDNN),正常RR间期差值均方根(rMSSD)。结果:OSAS组中,频域分析指标:LF,HF,均低于单纯鼾症组,LF/HF高于对照组,时域分析指标:SDNN,rMSSD均低于对照组。结论:OSAHS患者心率变异性降低。
Heart rate variability (HRV) is an important point to judge a person’s state in modern medicine. This paper is aimed to research a person’s fatigue level connected with vagal nerve based on the HRV using the improved Welch method. The process of this method is that it firstly uses a time window function on the signal to be processed, then sets the length of time according to the requirement, and finally makes frequency domain analysis. Compared with classical periodogram method, the variance and consistency of the present method have been improved. We can set time span freely using this method (at present, the time of international standard to measure HRV is 5 minutes). This paper analyses the HRV’s characteristics of fatigue crowd based on the database provided by PhysioNet. We therefore draw the conclusion that the accuracy of Welch analyzing HRV combining with appropriate window function has been improved enormously, and when the person changes to fatigue, the vagal activity is diminished and sympathetic activity is raised.
Heart rate is the most common index to directly monitor the level of physical stress by comparing the subject's heart rate with an appropriate "target heart rate" during exercise. However, heart rate only reveals the cardiac rhythm of the complex cardiovascular changes that take place during exercise. It is essential to get the dynamic response of the heart to exercise with various indices instead of only one single measurement. Based on the rest-workload alternating pattern, this paper screens the sensitive indices of exercise load from electrocardiogram (ECG) rhythm and waveform, including 4 time domain indices and 4 frequency domain indices of heart rate variability (HRV), 3 indices of waveform similarity and 2 indices of high frequency noise. In conclusion, RR interval (heart rate) is a reliable index for the realtime monitoring of exercise intensity, which has strong linear correlation with load intensity. The ECG waveform similarity and HRV indices are useful for the evaluation of exercise load.
Cough variant asthma is a special type of asthma, of which the only or main symptom is cough, and it is the main cause of chronic cough. Early diagnosis and treatment can prevent cough variant asthma developing into typical asthma. This article summarizes the progress in pathogenesis, diagnosis and assessment, treatment, and prognosis of cough variant asthma, aiming to improve the prevention and treatment of this disease, and increase the patients’ quality of life.
目的：观察卡介菌多糖核酸注射液在小儿咳嗽变异性哮喘治疗应用的疗效。方法：将本科40例咳嗽变异性哮喘患儿，随机分为治疗组和对照组(各20例)。治疗组给予BCG-PSN+必可酮气雾剂，对照组：给予单用必可酮气雾剂吸入，连续吸入6周，观察疗效，并进行统计学处理。结果：治疗组总有效率为95%，对照组总有效率为70%，统计学处理总有效率有显著差异(Plt;0.01)。结论：卡介菌多糖核酸(polysaccharide nucleic acidfraction of BCG，BCG-PSN)能有效地控制咳嗽变异性哮喘(CVA)的呼吸道的反复感染，提高免疫功能；与必可酮配合，能有效地控制CVA的复发。