心律失常患者红细胞的光镊拉曼光谱

利用激光光镊拉曼光谱系统,测定健康者红细胞(RBC)和心律失常患者红细胞的拉曼光谱,对健康者红细胞与心律失常患者红细胞的拉曼光谱进行了比较,发现心律失常患者红细胞的部分谱线整体强度有所减弱,部分谱线发生了频移;另外,低强度He-Ne激光对心律失常患者红细胞也存在一定的影响.根据拉曼光谱差异性,进一步探讨其红细胞内容物的...     

Heartbeats classification using QRS and T waves autoregressive features and RR interval features

This paper describes a method for the classification of heartbeats based on electrocardiogram QRS complex and T wave autoregressive (AR) features and interbeat distance (RR interval) features. The QRS complex (length n samples) is modelled using AR model of order P. A second AR model of order P₁ is applied to the electrocardiogram segment including ST segment and T wave (ST/T segment) with a length of n₁ samples. In addition, RR interval features such as the distance between one heartbeat and its preceding (pre‐RR) and following (post‐RR) heartbeats are extracted. The use of AR modelling is motivated by the fact that QRS complex and ST/T segment corresponding to normal beats present different patterns (in shapes and amplitudes) than those corresponding to ventricular ectopic beats. Lengths and AR model orders that minimize the number of misclassifications are determined. Obtained features are used to train and test support vector machine classifier. The proposed method is tested on MIT/BIH Arrhythmia Database and it is compared to state of the art methods. Overall classification accuracy reached 97.02%, whereas it reached 98.86% in the case of subject‐specific scheme. Results are better or comparable to those obtained by state of the art methods.     

卷积神经网络混合模型的心律失常分类算法

心律失常表现为不规则的心跳,心律失常类型的判断是心血管疾病早期预防和诊断的关键.为提高心律失常分类的准确率和速度,实现心律失常类型的自动识别,研究并提出了一种以卷积神经网络(convolutional neural network,CNN)为核心的7层混合模型结构.为保持心拍的完整性,根据R-R间期对心电信号进行动态分...     

超声联合sST2在鉴别不同类型心力衰竭的价值研究

目的探讨超声联合可溶性生长刺激表达基因2蛋白(sST2)在不同类型心衰中的应用价值方法以2018年7月—2019年10月本院收治的117例疑似心衰患者为研究对象,患者入院后分别在心脏部位进行超声心动图检查,抽取肘静脉血并采用酶联免疫吸附法测定患者血浆sST2水平。依据临床病史、体格检查及心电图、超声心动图等综合检查结果确诊为心衰的患者为病例组,非心衰患者为对照组,比较单独应用超声、血浆sST2诊断心衰效能;按照左心室射血分数(LVEF)及利钠肽、临床症状等将心衰患者分为降低型心衰组(HF-rEF组)、射血分数保留型心衰组(HF-pEF组)及射血分数中间值型心衰组(HF-mrEF组),比较不同组患者的超声特点及sST2水平,计算二者单独及联合鉴别不同类型心衰的效能。结果超声联合sST2诊断心衰时灵敏度为93.3%,特异度为67.2%,曲线下面积(AUC)为0.967;HF-rEF组的LAVI显著高于HF-pEF组、HF-mrEF组,IVSd值显著低于HF-pEF组、HF-mrEF组(P均<0.05);HF-rEF组的sST2为(95.64±35.23)ng/mL,显著高于HF-pEF组、HF-mrEF组的(54.27±26.85)ng/mL、(83.64±33.41)ng/mL,HF-mrEF组则显著高于HF-pEF组(P均<0.05),三组的LVPWd比较无统计学意义(P>0.05);联合诊断HE-rEF时,其灵敏度为73.7%,特异度为84.9%,曲线下面积(AUC)为0.867;联合鉴别HE-pEF时,其灵敏度为79.6%,特异度为89.5%,曲线下面积(AUC)为0.917。结论超声联合sST2较单一检查不同类型的心衰优势明显,可提高诊断效能,有助于临床进行疾病鉴别。     

托拉塞米联合左卡尼汀治疗慢性心力衰竭的疗效分析

目的：探究托拉塞米联合左卡尼汀治疗慢性心力衰竭（CHF）的疗效。方法：2018年7月至2020年7月,选择本院收治的CHF患者75例作为本次研究对象,按照随机数字表法分成对照组37例和研究组38例,对照组给予左卡尼汀治疗,研究组在对照组基础上给予托拉塞米治疗。评价两组临床疗效,对比两组治疗前后心室重塑指标、6分钟步行试验（6MWT）距离,检测血清半乳糖凝集素3（Gal-3）、白细胞介素33（IL-33）、超敏C-反应蛋白（hs-CRP）水平及血浆氨基末端脑钠肽前体（NT-proBNP）、脑钠肽（BNP）表达水平。结果：（1）治疗后,研究组临床总有效率（92.11%）高于对照组（72.97%）（P<0.05）。（2）与治疗前相比,治疗后两组舒张期室间隔厚度（IVST）、舒张期左室后壁厚度（LVPWT）均减小（P<0.05）,左室质量指数（LVMI）、左心室射血分数（LVEF）均增大（P<0.05）;与对照组相比,治疗后研究组IVST、LVPWT均减小（P<0.05）,LVMI、LVEF均增大（P<0.05）。（3）与治疗前相比,治疗后两组血清Gal-3、IL-33、hs-CRP水平均降低（P<0.05）;与对照组相比,治疗后研究组血清Gal-3、IL-33、hs-CRP水平均降低（P<0.05）。（4）与治疗前相比,治疗后两组6MWT距离均增加（P<0.05）;与对照组相比,治疗后研究组6MWT距离增加（P<0.05）。（5）与治疗前相比,治疗后两组血浆NT-proBNP、BNP表达水平均降低（P<0.05）;与对照组相比,治疗后研究组血浆NT-proBNP、BNP表达水平均降低（P<0.05）。结论：托拉塞米联合左卡尼汀治疗CHF,能显著改善患者心室重塑指标,改善运动功能,下调血清炎症水平并提高心功能,疗效确切。     

丹参预防自发性高血压大鼠左室肥厚及其对c-fos 表达的影响

目的: 观察丹参预防自发性高血压大鼠左室肥厚的作用,并研究其对心肌c-fos 的影响。方法: 18 只8 周龄的自发性高血压大鼠随机分成3 组,每组6 只。对照组于8 周处死,丹参组及高血压组分别经腹腔注射丹参或蒸馏水(1 g·kg^-1·d^-1),共10周。测量大鼠尾动脉收缩压(SBP)及左心室重量指数(LVMI)。应用HE 和VG 染色、免疫组织化学的方法,结合计算机图像分析技术,检测心肌细胞的直径和面积、心肌组织胶原体积比例(CVF)、血管周围胶原面积和管腔面积比例(PVCA)以及c-fos 表达。结果: 与8 周龄的自发性高血压大鼠相比,18 周龄大鼠的SBP、LVMI、心肌细胞的直径、面积、CVF、PVCA显著增加,c-fos 表达明显,丹参治疗可抑制LVH的发展和心肌组织c-fos 的表达,但对收缩压无明显改变。结论: 长期应用丹参治疗可预防自发性高血压大鼠左室肥厚的形成,其机制可能与丹参降低了心肌细胞c-fos 的表达有关。     

Lethal cardiac arrhythmia during central venous catheterization in a uremic patient: A case report and review of the literature

Double‐lumen central venous catheter (CVC) is a rapid access technique for hemodialysis (HD) when an arteriovenous fistula or graft is not available. A variety of procedure‐related complications have been reported, such as infection and pneumothorax, but serious cardiac complications are relatively less mentioned. We report a uremic woman with preexisting left bundle branch block who required emergent HD and received jugular double‐lumen CVC insertion, which was complicated by short‐duration ventricular tachycardia followed by complete atrio‐ventricular block and bradycardia. Pharmacological management did not reverse heart rate and rhythm. External pacing was not applied because she remained hemodynamically stable in the course of HD. Heart rate returned to sinus rhythm with left bundle branch block 4 hours later and did not recur through the whole admission period. We speculate that the transient arrhythmia might have been induced by mechanical contact with the ventricular wall during the procedure with the guided metallic wire. In conclusion, physicians responsible for CVC catheterization should pay more attention to patients with preexisting cardiac arrhythmia to prevent such technical mistakes from transpiring.     

Hemodialysis does not impair ventricular functions over 2 years

We aimed to evaluate the long-term effect of hemodialysis (HD) treatment on left and right ventricular (LV and RV) functions in patients with end-stage renal disease. The study population consisted of 22 patients with newly diagnosed end-stage renal disease. Before an arteriovenous fistula was surgically created for HD, the patients were evaluated by echocardiography for systolic and diastolic functions. After the first HD session (mean 24.22 ± 2.14 months), the second echocardiographic evaluations were performed. Left ventricular and RV functions before and after long-term HD treatment were compared. The mean age was 55 ± 13 years and 10 (45%) of the patients were female. After long-term HD treatment, the isovolumic relaxation time was significantly decreased; however, the peak early (E) and late (A) diastolic mitral inflow velocities, E/A ratio, and deceleration time of E wave were not significantly different from the baseline measurements. Also, there was no significantly change in the early diastolic velocity (Ea) of the lateral mitral anulus and the E/Ea ratio. Pulmonary vein peak diastolic velocity, peak atrial reversal velocity, and peak atrial reversal velocity duration remained almost unchanged even though the pulmonary vein peak systolic velocity and the pulmonary vein peak systolic velocity/pulmonary vein peak diastolic velocity ratio were significantly lower after long-term HD treatment. In addition, LV systolic functions, LV diameters, LV mass index, left atrium size, and RV diastolic functions were not statistically different after long-term HD treatment. The myocardium is exposed to hemodynamic, metabolic, and neuro-humoral abnormalities during HD treatment; however, the long-term effects of HD on ventricular functions are not clearly known. The present study showed that the long-term effects of HD on LV and RV functions were insignificant in patients with end-stage renal disease. We have demonstrated that the LV and RV functions did not change significantly after long-term HD treatment. We suggest that this result may be due to regulated blood pressure levels of the patients, treatment of anemia and other metabolic disorders during the HD period and the prevention of weight gain and hypervolemia.     

Ventricular arrhythmia in dialysis patients: A link with higher hemoglobin levels?

We investigated the frequencies and associated risk factors of cardiac arrhythmias and heart rate variability (HRV) in hemodialysis (HD) patients. One hundred fifty prevalent HD patients underwent 48-hour Holter monitoring. Holter monitoring was analyzed in 4 phases: early post-HD phase (12 hours), late post-HD phase (20 hours), pre-HD phase (12 hours), and HD phase (4 hours). Echocardiography was applied to measure the left ventricular mass index in a subgroup of patients (n: 52). Patients with ventricular premature contraction (VPC) were significantly older, had a longer HD duration, and higher hemoglobin (Hb) levels. Left ventricular mass index was significantly correlated with the frequency of VPC, during the HD and pre HD phases (r: 0.435, 0.312, respectively). In logistic regression analysis, patients with Hb level >11.9 g/dL (high tertile) had a 4.5-fold increased risk of VPC compared with those with Hb levels <10.8 g/dL (P: 0.04). In HRV analysis, age (P<0.001), and diabetes (P: 0.03) were found to be independent predictors of low standard deviation of all mean normal-to-normal RR intervals. Increased left ventricular mass index is associated with a high frequency of VPC in the pre-HD and HD periods. The occurrence of VPC is predicted by older age, longer dialysis duration, and higher Hb levels, while older age and diabetes are the determinants of HRV. The relation between higher Hb levels and the frequency of VPC might provide a clue for the explanation of the detrimental effect of higher Hb levels on HD patients.