OBJECTIVE:To investigate the correlation between serum Beclin 1 levels and multi-vessel disease (MVD). METHODS:A total of 169 participants were enrolled in this retrospective study. Based on coronary angiographic findings, 106 patients diagnosed with coronary heart disease (CHD) were categorized into single-vessel disease (SVD) and MVD groups, and their Gensini scores were calculated respectively. General demographic data and serum biochemical indicators were collected. Serum Beclin 1 concentration was detected by enzyme-linked immunosorbent assay. The differential expression of Beclin 1 among the three groups was compared and analyzed. Logistic regression models and receiver operating characteristic (ROC) curves were used to explore the association between Beclin 1 level and MVD. RESULTS:Compared to the control group, Beclin 1 levels were significantly decreased in both the groups, with the lowest level observed in the MVD group [2.45 (1.69, 4.17), 2.64 (2.24, 2.89), 1.09 (0.66, 1.78), P<0.001]. Multivariate analysis results demonstrated that Gensini score was an independent risk factor for MVD (OR = 1.045, 95% CI: 1.018-1.090, P<0.001), while Beclin 1 (OR = 0.372, 95% CI: 0.174-0.695, P = 0.001) and low-density lipoprotein cholesterol (LDL-C) (OR = 0.295, 95% CI: 0.128-0.619, P<0.001) served as independent protective factors against MVD The combined model (Gensini score + Beclin 1 + LDL-C yielded an AUC of 0.936, with an optimal predictive probability cutoff of ≥0.664, a sensitivity of 0.911, and a specificity of 0.963. Compared to the basic model (Gensini score + LDL-C), the combined model exhibited a higher AUC, indicating that the addition of Beclin 1 effectively improved the predictive efficacy for MVD. CONCLUSION:The combination of Beclin 1 level, Gensini score, and LDL-C had good predictive value for MVD.

Early identification of high-risk individuals for coronary artery disease (CAD) is critical, especially in acute coronary syndrome (ACS) patients who face elevated risks of adverse cardiovascular events and are in need of intensified secondary prevention. This study aimed to investigate the combined value of the triglyceride-glucose (TyG) index—a surrogate marker of insulin resistance—and the systemic inflammatory response index (SIRI), calculated as (neutrophil count × monocyte count)/ lyphocyte count, in assessing coronary artery stenosis severity, proposing a cost-effective strategy for risk stratification in ACS management. A retrospective cohort study included 415 ACS patients diagnosed by coronary angiography at Beijing University of Chinese Medicine Third Affiliated Hospital (June 2021–February 2024). Patients were stratified into low stenosis (Gensini score < 34, n = 204) and high stenosis (Gensini score ≥ 34, n = 211) groups based on the median Gensini score. Clinical parameters and inflammatory markers were analyzed using logistic regression and ROC curves. High stenosis group showed significantly higher TyG (1.95 vs. 1.42, P < 0.001) and SIRI (1.07 vs. 0.75, P < 0.001) than the low stenosis group. Both indices independently associated with severe stenosis (OR = 3.094 and 2.064, P < 0.001). The combined TyG-SIRI model achieved an AUC of 0.744 (sensitivity 61.61

Background:While the hybrid intravascular ultrasound-optical coherence tomography (IVUS-OCT) imaging system offers theoretical advantages for enhanced characterization of vascular morphology and histopathology through multimodal integration, its clinical efficacy lacks systematic validation. We conducted a comprehensive comparative analysis of this novel hybrid imaging modality against conventional single-modality OCT and IVUS systems, aiming to establish an evidence-based foundation for its clinical implementation and broader adoption in interventional cardiology practice. Objective:To evaluate the clinical advantages of hybrid intravascular ultrasound-optical coherence tomography (IVUS-OCT) system compared with single-modality imaging techniques in clinical practice. Methods:The hybrid IVUS-OCT intracoronary imaging system was employed to evaluate the characteristics of coronary atherosclerotic plaques and the immediate post-stent outcomes and compared against single-modality OCT and IVUS. The post-stent immediate effects were evaluated by the clear stent capture rate (CSCR), identification of incomplete stent apposition, tissue protrusion, and stent edge dissection. Results:74 patients underwent successful hybrid imaging (82 vessels imaged). Plaque analysis (23 vessels) identified 41 plaques [21 lipid, 20 calcified, 2 thin-cap fibroatheromas (TCFAs)]. OCT alone detected 21 lipid, 16 calcified, 3 possible TCFAs (maximal calcified arc accuracy: 68.75%). IVUS alone detected 15 lipid, 20 calcified, 0 TCFAs (maximal calcified arc accuracy: 85%). For post-stent evaluation (74 vessels), hybrid imaging visualized all stents (CSCR = 100%), detecting 23 incomplete stent apposition, 10 tissue protrusions, and 10 edge dissections. OCT detected 66 CSCR (89.19%), 23 incomplete stent apposition (100%), 10 tissue protrusions (100%), and 10 edge dissections (100%). IVUS detected 37 CSCR (50%), 8 incomplete stent apposition (34.78%), 2 tissue protrusions (20%), and 7 edge dissections (70%). Hybrid IVUS-OCT and OCT significantly outperformed IVUS in CSCR, tissue protrusion, and incomplete stent apposition detection (P < 0.05). Conclusion:The hybrid IVUS-OCT intracoronary imaging system outperforms single-modality IVUS or OCT in evaluating coronary atherosclerotic plaque characteristics and immediate post-stent outcomes.

This study aimed to identify causes of in-hospital death in ST-segment elevation myocardial infarction (STEMI) patients undergoing percutaneous coronary intervention (PPCI) in the Beijing metropolitan area. A total of 56,763 PPCIs were performed at 56 eligible hospitals between January 1, 2010, and December 31, 2018, among which 1,278 patients died. Causes of death were analyzed and finally adjudicated by a review board. The overall in-hospital mortality rate was 2.25%, ranging annually from 1.96% to 2.48% over the study period. Of these, 1,069 (83.6%) deaths were attributed to disease severity-related causes, mainly cardiogenic shock of 44.4%, mechanical complications of 15.2%, malignant arrhythmia of 8.1% and heart failure of 6.2%. Another 209 (16.4%) patients died from PPCI-related complications, including coronary no-reflow of 8.5%, stent thrombosis of 3.5%, and PPCI-related bleeding of 2.4%. The incidence of PPCI-related death has decreased from 1.02% in 2010 to 0.15% in 2018 (p <0.001). Hospitals in the highest quartile PPCI volume (>130 PPCI annually) had lower incidence of in-hospital death (1.97% vs 2.62%, 2.99%, and 2.56%, p <0.001), disease severity-related death (1.66% vs 2.13%, 2.4%, and 2.17%, p <0.001) and PPCI-related death (0.31% vs 0.48%, 0.59%, and 0.39%, p = 0.003), as compared to those with the first, second and third quartiles of annual PPCI volume. In conclusion, among patients with STEMI and treated with PPCI, in-hospital mortality keeps at a relatively low level in Beijing area. Most deaths are due to pathophysiological deteriorations following STEMI. Hospital PPCI volume remains serve as an important indicator for quality of care.

Objective: To explore the possibility of using a pulse measuring instrument to help the pattern differentiation by investigating the characteristics of radial pressure wave analysis in patients with Qi deficiency induced blood stasis pattern in coronary heart disease. Methods: Patients who were hospitalized in the Cardiovascular Department of the Third Affiliated Hospital of Beijing University of Chinese Medicine from March 2023 to April 2023, diagnosed to be coronary heart disease, enrolled in the study. All included patients' age, gender, and BMI values were collected, the visit measured the subject's radial pressure waves. Radial pressure wave data were continuously recorded for 12-s using a HMYH1300 pulse measuring instrument. According to the theory of "Qi and blood resonance", the radial pressure wave harmonic indexes C0-C7 were calculated by Fourier transform. The patients were divided into a Qi deficiency induced blood stasis pattern group and a non-Qi deficiency induced blood stasis pattern group according to the standard of " Chinese Medicine Clinical Diagnostic and Treatment Terminology " . Baseline comparisons were made between the two groups by using statistical methods such as t-test, nonparametric test, chi-square test, and the left and right hands’ radial pressure waves were compared either. Combining all included patients’ radial pressure waves of left and right hands, the corresponding indexes between two groups were compared. Then, using the logistic regressing analysis to explore the relationship between Qi deficiency induced blood stasis pattern and the radial pressure wave, drawing ROC curves and running bootstrap internal validation to prove their accuracy. Results: A total of 111 patients were included, of whom 73 were in the Qi deficiency induced blood stasis pattern group and 38 were in the non-Qi deficiency induced blood stasis pattern group. No significant difference was found in the baseline between the two groups (P > 0.05). A comparison of two groups showed significant differences in C0, C2, C3, and C5 (P<0.05). Logistic regressing analysis showed that the lower the C2 and C3 are, the higher the risk of Qi deficiency induced blood stasis pattern the included patients have (C2 OR: 0.896, 95% CI: 0.854-0.939, C3 OR: 0.959, 95% CI: 0.935-0.984). The area under the curve was 0.873 (95% CI: 0.825-0.922), and bootstrap internal validation’s 95%CI was (0.8449, 0.9364). Conclusion: The effects on the radial pressure wave, especially on hemodynamic index C2 and C3, independent of gender, age, and BMI, may explain the increased risk of Qi deficiency induced blood stasis pattern in patients with coronary heart disease. This and past studies suggested that radial pressure waves C2 and C3 refer to the kidney meridian of foot-Shaoyin, and the spleen meridian of foot-Taiyin. This study provided further clinical evidence to support the basic theory of traditional Chinese medicine that describes the Qi deficiency of the spleen and kidney related to the Qi deficiency induced blood stasis pattern.

卵圆孔未闭(patent foramen ovale,PFO)是左、右心房之间的开放交通,属于常见的先天性心脏结构异常,约25%的成年人存在PFO[1].PFO相关疾病的临床表现多样,以不明原因卒中(隐源性卒中)、偏头痛为主,也可能出现短暂性脑缺血发作(transient ischemic attack,TIA)、斜卧呼吸-直立低氧血症、不明原因晕厥,乃至非动脉粥样硬化性心肌梗死[2-4].

目的 探究高龄女性射血分数保留的心力衰竭(HFpEF)患者的临床特点及其影响因素.方法 连续入选2017年1月至2020年12月就诊于北京中医药大学东直门医院心血管科年龄≥80岁的女性心力衰竭患者292例,根据LVEF分为射血分数减低的心力衰竭(HFrEF)组87例HFpEF组205例.比较2组临床资料,采用多因素logistic回归分析.结果 HFpEF组心房颤动比例、血钾和LVEF明显高于HFrEF组,高脂血症、心肌梗死病史、冠心病血运重建比例及心率明显低于HFrEF组(P<0.05,P<0.01).多因素logistic回归分析显示,心率(95％CI:1.008～1.056,P=0.009)、心肌梗死病史(95％CI:2.718～9.950,P=0.000)、冠心病血运重建(95％CI:1.042～3.648,P=0.037)、高脂血症(95％CI:1.615～6.068,P=0.001)是心力衰竭发作的独立危险因素.结论 心肌梗死病史、高脂血症、冠心病血运重建术、心率是高龄女性心力衰竭的危险因素.

我国冠心病接受经皮冠状动脉介入术（percutaneous coronary intervention，PCI）治疗的患者人数者逐年增加，目前年PCI例数已达100万例，成为治疗冠心病最重要手段之一。PCI术后规范抗血小板治疗对于减少心血管事件至关重要，可显著减少如心血管病死亡、心肌梗死、缺血性卒中、支架内血栓等不良心血管事件。国内外对PCI术后抗血小板治疗方案均有多部指南发布和不断更新，我国于2021年首次发布了《冠心病双联抗血小板治疗中国专家共识》，对规范双联抗血小板药物（dual antiplatelet therapy，DAPT）在PCI中的应用将起到重要指导作用 ［1］。了解各种类型冠心病PCI术后抗血小板治疗的方案及治疗时程的相关问题，有助于促进患者的健康管理。

Abstract Background Trimethylamine N-oxide (TMAO)-related metabolites are associated with the pathogenesis of atherosclerotic cardiovascular disease (ASCVD) and are known to disrupt lipid metabolism. The aims of this study were to evaluate the associations between TMAO-related metabolites and blood lipids and determine how lowering the lipid profile via rosuvastatin therapy influences TMAO-related metabolites. Methods A total of 112 patients with suspected ASCVD were enrolled in this study. The levels of plasma TMAO-related metabolites, including TMAO, choline, carnitine, betaine, and γ-butyrobetaine (GBB), were analyzed by stable isotope dilution liquid chromatography-tandem mass spectrometry (LC/MS/MS) before and after rosuvastatin therapy in all patients. Statistical methods were used to detect the associations between TMAO-related metabolites and blood lipids and determine how rosuvastatin therapy alters the levels of these metabolites. Results A significant positive correlation was found between TMAO and triglycerides (TG) (r = 0.303, P < 0.05). Furthermore, significant negative correlations were found between TMAO and high-density lipoprotein cholesterol (HDL-c) and between betaine and low-density lipoprotein cholesterol (LDL-c) (r = − 0.405 and − 0.308, respectively, both P < 0.01). Compared to baseline, significantly lower TMAO levels and higher carnitine, betaine and GBB levels were observed after rosuvastatin therapy, while the lipids decreased significantly (P < 0.05). The significant correlation between TMAO and TG or between betaine and LDL-c disappeared after rosuvastatin therapy (r = 0.050 and − 0.172, respectively, both P > 0.05). However, a significantly positive association between carnitine and TC and a negative association between carnitine and LDL-c or between betaine and TG were found after adjustment for sex, age, body mass index (BMI) and lipids (P < 0.05). Conclusions This study suggests that TMAO-related metabolites are significantly associated with blood lipids, although some of them are changed postrosuvastatin therapy. Lower TMAO and higher TMAO precursors were observed after rosuvastatin therapy compared to baseline. This study indicates that elevated TMAO precursors after rosuvastatin therapy and their potential impact on ASCVD should be considered in the clinic.

稳定性冠心病是指疾病保持相对稳定状态，但可以随时因斑块破裂或侵蚀而变为不稳定导致急性冠脉事件。文章介绍合理使用评价稳定性冠心病风险的各种方法，提高对稳定性冠心病临床诊治能力。

目的 分析老年患者血浆氧化三甲胺(TMAO)水平与颈动脉斑块负荷的关系.方法 入选2013年1月～2016年12月首都医科大学附属北京天坛医院就诊的可疑心脑血管疾病的老年患者79例,根据颈动脉斑块是否形成富脂质坏死脂核(LRNC)分为无LRNC组23例和LRNC组56例.应用高效液相色谱法测血浆TMAO水平,进行MRI检查,计算颈动脉斑块的LRNC大小和总管壁体积(TWV),用多因素logistic回归分析和相关性分析.结果 与无LRNC组比较,LRNC组血浆TMAO水平明显升高[(7.00±6.29)μmol/L vs(3.29±1.99)μmol/L,P<0.05].多因素logistic回归分析校正性别、年龄、体质量指数和高脂血症以及合并疾病等因素后,血浆TMAO水平依然是LRNC形成的危险因素(P<0.05).所有患者血浆TMAO水平与颈动脉斑块的TWV呈正相关(r=0.295,P<0.05);LRNC组患者血浆TMAO水平与LRNC大小呈正相关(r=0.576,P<0.01).结论 老年患者血浆TMAO水平与颈动脉斑块的LRNC形成及大小密切相关,且与TWV也密切相关.

简要介绍《非ST段抬高型急性冠状动脉综合征基层诊疗指南（2019年）》制订的背景和涵盖内容。基层医疗机构医师应熟悉心肌损伤标志物肌钙蛋白（cTn）检测在非ST段抬高型急性冠状动脉综合征早期诊断中的重要性，重视其早期评估和危险分层，规范治疗策略，以改善长期预后。

Background: Gut microbiota is contributed to the variations of blood lipids, and statins are found to affect the gut microbiota compositions. The aims of this study were to evaluate the associations of trimethylamine N-oxide (TMAO) and related precursors with blood lipids and the effect of rosuvastatin therapy on them. Methods: Totally 112 patients with suspected cardiovascular disease and received regular rosuvastatin therapy were enrolled in this study previously. The TMAO, choline, carnitine, betaine and γ-butyrobetaine (γBB) levels of the patients were analyzed by stable isotope dilution liquid chromatography-tandem mass spectrometry (LC/MS/MS), and the associations between them and blood lipids were analyzed by statistical methods. Results: Plasma TMAO was correlated with triglyceride positively ( r =0.303, p <0.05) and high density lipoprotein cholesterol (HDL-c) negatively ( r =-0.405, p <0.001). Plasma betaine was correlated with low density lipoprotein cholesterol negatively ( r =-0.308, p <0.01). After adjustment of sex, age, body mass index, blood lipids and concomitant diseases, the association between TMAO and HDL-c was still significant ( p <0.05). Besides, the correlation between TMAO and HDL-c still existed after rosuvastatin therapy ( r =-0.253, p <0.01). Rosuvastatin therapy could decrease TMAO levels and increase carnitine, betaine and γBB levels significantly when it lowering the blood lipids. Conclusions: These results indicated that TMAO and related precursors were associated with blood lipids significantly, especially HDL-c. Rosuvastatin therapy not only affects the blood lipids, but also influences the levels of TMAO and related precursors. Trail registration: This study was retrospectively registered at http://clinicaltrials.gov/ (NCT02305862).

目的 探讨血浆中氧化三甲胺(TMAO)水平与体质量指数(BMI)的相关性.方法 选取2014年1月 ～2016年12月北京天坛医院心内科可疑冠心病(CHD)患者86例.利用稳定同位素液相色谱/质谱法测定患者血浆TMAO水平,并计算患者的BMI,根据BMI将患者分为体重正常组、超重组和肥胖组.双变量Correlate分析血浆TMAO水平与BMI的相关性,并比较不同BMI组间血浆TMAO水平的差异.结果 血浆TMAO水平和机体BMI具有显著的相关性(r=0.404,P<0.001);与BMI正常组相比,超重组、肥胖组(7.47±6.23)μmol/L vs.(3.28±2.44)μmol/L,(10.64±6.96)μmol/L vs.(3.28±2.44)μmol/L具有较高的血浆TMAO水平,差异有统计学意义(P<0.05).结论 血浆TMAO的水平与机体BMI之间具有显著的正相关关系.

目的 探索血浆中氧化三甲胺(trimethylamine N-oxide,TMAO)及其前体物质的浓度与冠状动脉粥样硬化性心脏病(以下简称冠心病)(coronary heart disease,CHD)的关系.方法 选取首都医科大学附属北京天坛医院心内科可疑CHD患者88例,根据冠状动脉造影结果将患者分为CHD组和对照组.利用高效液相法测患者血浆TMAO及其前体物质胆碱、肉碱、三甲胺乙内酯和三甲氨基丁内盐的浓度,分析两组患者血浆TMAO浓度及其前体物质与CHD的关系.结果 CHD组患者血浆TMAO浓度明显升高,差异有统计学意义[(6.20±3.57)μmol/L vs(3.90±2.26)μmol/L,P<0.05];两组血浆中胆碱、肉碱、三甲胺乙内酯和三甲氨基丁内盐浓度差异均无统计学意义(P>0.05).多因素Logistic回归分析,血浆TMAO浓度与CHD有关联(OR=1.35,P<0.05),血浆TMAO浓度升高,CHD的危险性增加.结论 血浆中TMAO的浓度与CHD密切相关,而与TMAO前体物质浓度无显著相关性.

目的:探讨冠心病合并脑血管狭窄与血浆氧化三甲胺(TMAO)的关系.方法:回顾性分析了2013年10月至2016年6月于首都医科大学附属北京天坛医院心内科就诊的158例住院患者.患者均在住院期间接受了冠状动脉造影及全脑血管造影,并依据检查结果分为:对照组(无冠心病及脑血管狭窄病变,n=20)、冠心病组(n=25)、脑血管狭窄组(n=17)和冠心病合并脑血管狭窄组(n=96).检测并比较各组空腹血浆TMAO及其前体物质左旋肉碱、胆碱、甜菜碱等水平,分别比较冠心病组、冠心病合并脑血管狭窄组Gensini评分与TMAO的相关性.结果:冠心病组与冠心病合并脑血管狭窄组中位TMAO水平分别为7.15(3.77,16.75)μmol、8.13(4.87,17.38)μmol,均明显高于对照组的3.22(2.19,9.00)μmol,P均<0.001;将各组TAMO水平经自然对数转化为正态分布后比较显示,冠心病组与冠心病合并脑血管狭窄组仍高于对照组(P均<0.01),也高于脑血管狭窄组(P均<0.05),不过冠心病组与冠心病合并脑血管狭窄组差异未见统计学意义(P=0.682);脑血管狭窄组与对照组差异未见统计学意义(P=0.582).各组间左旋肉碱、胆碱、甜菜碱血浆水平差异未见统计学意义(P>0.05).在冠心病组,TMAO水平与Gensini评分正相关(r=0.569,P=0.009),左旋肉碱水平与Gensini评分负相关(r=-0.700,P=0.001),胆碱、甜菜碱水平与Gensini评分未见明显相关;在冠心病合并脑血管狭窄组,TMAO、左旋肉碱、胆碱、甜菜碱血浆水平均未见与Gensini评分明显相关.结论:冠心病合并脑血管狭窄与血浆TMAO水平升高无关.

目的 分析老年女性血浆氧化三甲胺(TMAO)水平的变化及其影响因素.方法 选择冠状动脉造影的可疑冠心病患者120例,男性52例,女性68例.以60岁为界,年龄≥60岁79例中,老年男性29例,老年女性50例;年龄＜60岁41例中,非老年男性23例,非老年女性18例.患者均检测血浆TMAO水平,采用相关性分析和多因素线性回归分析.结果 老年女性血浆TMAO水平显著高于非老年女性[(7.94±6.57)μmol/L vs (4.34±5.30)μmol/L,P＜0.05],但与老年男性无明显差异[(7.94±6.57)上mol/L vs (5.70±4.02)μmol/L,P＞0.05].相关性分析显示,老年女性血浆TMAO水平与体质量指数、TG、HDL-C水平以及冠心病和糖尿病显著相关(P＜0.05,P＜0.01);多因素线性回归分析显示,体质量指数和糖尿病是影响老年女性血浆TMAO水平的危险因素(P＜0.05).结论 老年女性血浆TMAO水平升高,与患者体质量指数和代谢性疾病密切相关.

从腊月二十三的祭灶开始,中华大地就开始进入到了春节的倒计时中;大年三十除夕之夜,全家人围坐在一起,在团圆、美满、幸福的氛围中享用年夜饭;随着初一开门炮仗的噼啪声,全国各地的人们开始了走亲访友的热潮,火热的气氛充满了节日的各个角落.而在医院,这个节日里本该安静、少有人至的地方,却屡屡上演着争分夺秒抢救急性心肌梗死患者的一幕.

The current study investigated the role of sRAGE in the production of IFN‑γ in macrophages with I/R treatment. The number of macrophages in myocardial tissues treated with I/R with or without sRAGE was determined via immunohistochemical staining. Proliferative activity of macrophages was analyzed by a 5‑BrdU incorporation assay. Differentiation of macrophages was detected via immunofluorescence staining of iNOS (M1 macrophage marker). IFN‑γ production, due to sRAGE stimulation, in Raw 264.7 macrophages and the NF‑κB signaling pathway were measured using western blotting. A ChIP assay was used to examine the interactions between NF‑κB and the promoter of IFN‑γ. The results showed that the number of macrophages in I/R‑treated myocardial tissues was increased following sRAGE infusion. Proliferation of macrophages was increased significantly in the presence of sRAGE; after I/R treatment, the cells preferred to differentiate into M1 macrophages. IFN‑γ expression in Raw 264.7 macrophages was suppressed by an NF‑κB inhibitor (Bay117082) but enhanced by sRAGE, with or without I/R treatment. Furthermore, sRAGE increased the phosphorylation of IκB, IKK and NF‑κB, as well as the translocation of NF‑κB into the nucleus of Raw 264.7 macrophages, with or without I/R treatment. ChIP results showed that sRAGE promoted NF‑κB binding to the promoter of IFN‑γ in Raw 264.7 macrophages. Therefore, the findings of the present study indicated that sRAGE protected the heart from I/R injuries, which might be mediated by promoting infiltration and the differentiation of macrophages into M1, which would then synthesize and secrete IFN‑γ through activating the NF‑κB signaling pathway.

晕厥是临床急症的常见症状,可由多种病因引起,其中血管迷走神经性晕厥发生率较高,且在临床中较易被误诊,这不仅需要医师提高对晕厥诊断和鉴别诊断的水平,而且需要建立多学科共同合作以确定晕厥病因。该文通过对1例误诊为癫痫、心肌缺血的血管迷走神经性晕厥的病例进行回顾性分析并结合文献探讨了血管迷走神经性晕厥的临床特征,以期提高临床上对血管迷走神经性晕厥的认识。