Prognostic value of electrophysiologic investigations in Brugada syndrome

INTRODUCTION: The prognostic value of electrophysiologic investigations in individuals with Brugada syndrome is unclear. Previous studies failed to determine its value because of a limited number of patients or lack of events during follow-up. We present data on the prognostic value of electrophysiologic studies in the largest cohort ever collected of patients with Brugada syndrome. METHODS AND RESULTS: Two hundred fifty-two individuals with an ECG diagnostic of Brugada syndrome were studied electrophysiologically. The diagnosis was made because of a classic ECG with a coved-type ST segment elevation in precordial leads V1 to V3. Of the 252 individuals, 116 had previously developed spontaneous symptoms (syncope or aborted sudden cardiac death) and 136 were asymptomatic at the time of diagnosis. A sustained ventricular arrhythmia was induced in 130 patients (51%). Symptomatic patients were more frequently inducible (73%) than asymptomatic individuals (33%) (P = 0.0001). Fifty-two individuals (21%) developed an arrhythmic event during a mean follow-up of 34 +/- 40 months. Inducibility was a powerful predictor of arrhythmic events during follow-up both in symptomatic and asymptomatic individuals. Overall accuracy of programmed ventricular stimulation to predict outcome was 67%. Overall accuracy in asymptomatic individuals was 70.5%, with a 99% negative predictive value. Overall accuracy in symptomatic patients was 62%, with only a 4.5% false-negative rate. No significant differences were found in the duration of the H-V interval during sinus rhythm between symptomatic or asymptomatic individuals. However, the H-V interval was significantly longer in the asymptomatic individuals who became symptomatic during follow-up compared with those who did not develop symptoms (59 +/- 8 msec vs 48 +/- 11 msec, respectively; P = 0.04). CONCLUSION: Inducibility of sustained ventricular arrhythmias is a good predictor of outcome in Brugada syndrome. In asymptomatic individuals, a prolonged H-V interval during sinus rhythm is associated with a higher risk of developing arrhythmic events during follow-up. Symptomatic patients require protective treatment even when they are not inducible. Asymptomatic patients can be reassured if they are noninducible.     

高血压性心脏病左心室重构进展中的组织蛋白酶S基因表达及其活性变化的临床意义

目的探讨组织蛋白酶S（CathepsinS，Cat S）在高血压性心脏病心室重构发生发展中的表达及其活性动态变化与心功能的关系。方法7周龄雄性Dahl盐敏感（DS）大鼠分别给予高负荷食盐（8％）或正常负荷食盐（0．3％）为12周和19周建立心肌肥厚（H-LVF）模型，心力衰竭模型（H-HF）及同龄对照组（12W-C和19W-C）。另设人体心肌生检标本作研究对象（高血压代偿性心肌肥厚患者7例，心力衰竭患者18例和正常对照6例）。RT-PCR和免疫组化分别检测Cat SmRNA及蛋白表达，酶谱法测定大鼠心肌组织中的Cat S活性，免疫印迹杂交检测心肌组织中的白介素1β蛋白表达，细胞荧光染色法检测培养心肌细胞Cat S的表达，心脏石蜡切片苦味酸-酸性品红染色法和van Gieson＇s染色法分析胶原蛋白和弹性蛋白含量，心脏超声和血流动力学测定心功能和心室重构。结果H-HF组大鼠和患者心肌中的Cat SmRNAs的表达显著高于19W-C组和H-LVF组大鼠和人（P〈0．01）。免疫组化法和in situ法分析显示增高的Cat SmRNA和蛋白主要表达于心肌细胞。H-HF组大鼠心肌的弹性蛋白分解能也显著高于19W-C（4．1倍）。H-LVF大鼠心肌间质弹性蛋白含量明显增加，而在H-HF大鼠则下降低于对照组水平。H-HF组心肌白介素IL1β蛋白含量显著高于19W-C。IL1β刺激心肌细胞的Cat S蛋白表达。心肌中的弹性蛋白酶表达与左心室射血分数呈显著负相关（r=-0．88，P〈0．05）。结论Cat S参与心室病理改变，是导致间质改变、心功能异常的主要因素之一，提示心肌Cat S在H-HF时心室重构发展中起重要作用。     

致心律失常性右室心肌病患者Epsilon波的检出率

Objective To investigate the prevalence of Epsilon wave in patients with arrhythmogenic right ventrieular cardiomyopathy (ARVC). Methods The Epsilon wave was detected in 32 patients [24 men, mean age (42.3±13.3) years] with ARVC using three different electrocardiography (ECG) recording methods: standard twelve leads ECG (S-ECG), right precordial leads ECG (R-ECG) and Fontaine bipolar precordiai leads ECG (F-ECG). The Epsilon wave was defined as wiggle, small spike wave and smooth potential between the end of the QRS complex and the beginning of the ST segment. Results Epsilon wave was detected in 37.5%, 37.5% and 50.0% patients with ARVC by S-ECG, R-ECG and F-ECG respectively. The detection rates derived from the three recording methods were similar(P ＞ 0.05). The Epsilon wave was only detectable by S-ECG in one case, by R-ECG in three cases, and by F-ECG in five cases. The detection rate of Epsilon wave was 50.0% by combined use of S-ECG and R-ECG (SR-ECG), 56.3% by combined use of S-ECG and F-ECG (SF-ECG), and 65.6% by combined use of the three recording methods (SRF-ECG). The detection rate was significantly higher by SF-ECG (56.3%) and SRF-ECG (65.6%) than by S-ECG alone (37.5%, all P ＜0.05). Most Epsilon waves detected by the S-ECG, R-ECG and F-ECG were small spiked waves. Conclusion Combined use of S-ECG, F-ECG and R-ECG could increase the detection rate of Epsilon wave in patients with ARVC.     

二维多普勒超声对中年和老年人高血压性左室肥厚的比较研究

应用二维多普勒超声对36例中年和54例老年人的高血压性在室肥厚（LVH）及心功能状态进行分析比较。结果：中年组LVH类型：不对称性室间隔肥厚(ASH）占40%,对称性肥厚（CH）46％。扩张性肥厚（DH）占14％；老年组：ASH23%，CH26％，DH51％。将中年组和老年组分别同正常对照组比较，除中年组LVDd、LVV、EF及CO差异无显著性外，其余各指标差异均有显著性（P＜0.01或P＜0.O01）。中年组和老年组比较，E峰和A／E比值差异无显著性，其余各指标差异有显著性（P＜0.05或P＜0.O01）。结论认为在左室肥厚早期，左室充盈功能降低，左房增大，左房代偿性收缩增强，向左室泵血增多，以维持恒定的房室压差弥补左室充盈不足，左室收缩功能可表现为正常；在LVH晚期，失代偿后左室收缩及舒张功能均降低。     

Comparison of biplane and single plane left ventricular volumes in atrial septal defect

The close agreement between biplane (BP) and single-plane (SP) angiographic estimates of left ventricular (LV) volumes results from the similarity of the minor axes measured in the right anterior oblique (RAO) and left anterior oblique (LAO) views. Disease states that alter LV geometry may change the length of one minor axis more than the other, producing a discrepancy between BP and SP volumes. To examine this hyposthesis, angiographically derived volumes in 21 patients with atrial septal defects (ASD) in which the LV appears to be compressed and flattened by an enlarged right ventricle, were compared to 100 normal control patients. In the control patients, the median SP estimate of end-diastolic volume (EDV) was 7.6% larger than the BP determination, whereas in patients with ASD, the median SP EDV estimate was 16.7% larger than the BP EDV (P<0.0001). The SP end-systolic volume (ESV) underestimated the BP value by 3.4% in controls but overestimated the BP ESV in patients with ASD by 4.3% (P<0.02). The overestimate of the SP EDV and SP ESV when compared to the BP volumes may be due to changes in either the minor axes or the appearance of the longest major axis in the LAO view. The longest major axis was found in the RAO view in 99% (99/100) of normals and 95% (20/21) of ASD patients (P?NS). The median ratio of RAO to LAO end-diastolic minor axes, however, was 1.07 in the normals and 1.17 for ASD patients. The median ratio of end-systolic minor axes was 0.97 for controls and 1.04 for ASD patients. Compression of the LV in patients with ASD shortens the LAO minor axis, resulting in a significantly greater SP overestimation of LV volume than occurs in normals. The degree of SP volume overestimate was not predicted by the magnitude of the left-to-right shunt or pulmonary pressure. This source of error affects all SP methods for determining left ventricular volume, including radionuclide techniques using static images.     

左室特发性室性心动过速折返路径标测和消融点的选择

报道 1 0例 (男 8、女 2 )左室特发性室性心动过速 (简称室速 )折返路径标测结果和选择折返路径的不同部位为消融点的消融效果。电生理检查常规插入右室心尖与冠状静脉窦电极 ,并经左、右股动脉分别插入大头电极和2 8 2mm间距冠状静脉窦 1 0极标测电极至左室 ,后者贴靠在室间隔表面。窦性心律时各电极对可依次记录到His束电位 (HP)、左束支电位 (LBP)和左后分支的蒲氏纤维电位 (PP) ,室速时仍可同时记录到上述各电位 ,但顺序相反 ,PP领先 ,HP最后 ;而各部位的V波激动顺序在窦性心律和室速时是相同的 ,都是远端电极 (PP以远 )的V波最早 ,近端电极 (HP)的V波最晚。大头电极置于PP电极对附近。结果 :1 0例中 9例能记录到折返路径各电位心内电图 ,折返路径记录成功率为 90 % ( 9/1 0 )。第 1例大头电极位于PP电极对略上方处放电 ,消融成功 ,但导致完全性左束支阻滞。第 2 ,3例开始在PP电极对略下方处放电 ,但凡未记录到PP的点 ,虽然V波最早 ,都是放电无效点。最后消融成功的点 ,都记录到最领先的PP。第 4例以后 ,都必须记录到最领先的PP后才放电 ,除 1例 2次放电成功外 ,都是 1次放电成功。 1 0例随访至今 3～ 1 8个月 ,未服任何抗心律失常药均无室速发作。结论 :左室标测法不仅对研究左室特发性室速的折返     

Radionuclide assessment of left ventricular function during dobutamine infusion in patients with coronary artery disease: comparison with ergometer exercise

The effects of dobutamine on left ventricular function were assessed employing radionuclide ventriculography (RNV) in 7 normal subjects (Group 1) and 21 patients with coronary artery disease (Group 2). After routine bicycle ergometer exercise RNV, dobutamine infusion was started at 5 micrograms/kg/min and the dosage was increased by 5 micrograms/kg/min every 4 minutes to a total of 15 micrograms/kg/min. In Group 1, left ventricular ejection fraction (LVEF) increased by both ergometer exercise and dobutamine infusion. In Group 2, LVEF did not increase during exercise, but increased during dobutamine infusion without evidence of significant myocardial ischemia. Only 2 patients in Group 2 had new regional wall motion abnormality. Left ventricular end-diastolic volume (LVEDV) in Group 2 increased from 191 +/- 19 to 210 +/- 18 ml during ergometer exercise, but decreased from 193 +/- 18 to 153 +/- 19 ml during dobutamine infusion. Short-term low-dose infusion of dobutamine may be used in patients without evidence of significant myocardial ischemia, but probably cannot be substituted for exercise testing in patients with mild to moderate coronary artery disease.     

生脉方治疗心力衰竭的药理作用研究进展

心力衰竭是威胁人类健康的重大疾病之一,其病理机制复杂,中医药防治心衰具有显著特色。中医理论认为气阴两虚是心衰患者的主要证候之一,生脉散为益气养阴的代表方。目前根据生脉散研制的中成药包括注射用益气复脉、生脉注射液、生脉散、生脉饮、参麦注射液、生脉胶囊等,被广泛用于治疗心脑血管疾病。从生脉方改善线粒体功能、抑制心室重塑、减轻心肌细胞的炎性反应3个方面综述了生脉方治疗心衰的研究进展,以期为心衰的防治提供依据。     

Upregulation of Sirt1 by tyrosol suppresses apoptosis and inflammation and modulates extracellular matrix remodeling in interleukin-1β-stimulated human nucleus pulposus cells through activation of PI3K/Akt pathway

Intervertebral disc degeneration (IDD) is the major pathogenesis of lower back pain. Tyrosol is a polyphenolic compound that exhibits anti-oxidant, anti-apoptotic, and anti-inflammatory effects. Herein, we explored the effects and mechanisms of tyrosol on IDD progression in interleukin (IL)-1β-stimulated human nucleus pulposus cells (HNPCs). Cell viability and apoptosis were detected by CCK-8 and flow cytometry analysis, respectively. The production of tumor necrosis factor-α (TNF-α), IL-6, nitric oxide (NO), and prostaglandin E2 (PGE2) was examined to evaluate inflammation. The mRNA expression of matrix metalloproteinases (MMPs) (MMP-3/9/13), collagen type II, SRY-related high mobility group box 9 (SOX-9), and aggrecan was measured by qRT-PCR. Protein levels of silent information regulator 2 homolog 1 (Sirt1), phosphorylated protein kinase B (p-Akt), Akt, collagen type II, SOX-9, and aggrecan were determined by western blot. Results showed that tyrosol attenuated IL-1β-induced viability reduction, apoptosis, and caspase-3/7 activity in HNPCs. The increase in the production of TNF-α, IL-6, NO, and PGE2 in IL-1β-treated HNPCs was abolished by tyrosol treatment. Tyrosol treatment reversed IL-1β-induced upregulation of MMP-3, MMP-9, and MMP-13, and downregulation of collagen II, SOX-9, and aggrecan in HNPCs. Additionally, tyrosol treatment activated the phosphatidylinositol 3-kinase (PI3K)/Akt pathway in IL-1β-stimulated HNPCs. Sirt1 was upregulated by tyrosol, and Sirt1 silencing inhibited Akt phosphorylation in HNPCs. Sirt1 knockdown attenuated the effects of tyrosol on IL-1β-induced apoptosis, inflammation, and ECM remodeling in HNPCs. In summary, upregulation of Sirt1 by tyrosol suppressed apoptosis and inflammation and regulated ECM remodeling in IL-1β-stimulated HNPCs through activation of PI3K/Akt pathway.     

Emodin ameliorates ovalbumin-induced airway remodeling in mice by suppressing airway smooth muscle cells proliferation

Increased number of airway smooth muscle cells (ASMCs) is a characteristic of airway remodeling in asthma. In this study we investigated whether emodin alleviated airway remodeling in a murine asthma model and reduced the proliferation of ASMCs in vitro. We provided in vivo evidence suggesting that intraperitoneal injection of emodin (20 mg/kg) 1 h prior to OVA challenge apparently alleviated the thickness of airway smooth muscle, the mass of alpha-smooth muscle actin (α-SMA), collagen deposition, epithelial damage, goblet cell hyperplasia, airway inflammation and airway hyperresponsiveness (AHR) in lung tissue. Meanwhile, we found that emodin suppressed the activation of the Akt pathway in lung tissue of allergic mouse models. Additionally, we found that emodin inhibited cellular proliferation and Akt activation in a dose-dependent manner in vitro. Furthermore, LY294002, an inhibitor for PI3K, abrogated serum-induced phosphorylation of Akt, and decreased the proliferation of ASMCs. These findings indicated that emodin alleviated ASMCs proliferation by inhibiting PI3K/Akt pathway in vivo and in vitro, which may provide a potential therapeutic option for airway smooth muscle remodeling in asthma.