动态心电图对阵发性心房颤动心电触发机制的分析

目的探讨阵发性心房颤动(PAf)心电触发因素及其部位,并评价其临床意义。方法对45例PAf患者的动态心电图人工回放,记录心房颤动(Af)发作次数、发作时间、发作前三个心房周期、联律间期,并根据触发Af的房性期前收缩的P波形态确定房性期前收缩部位。结果45例PAf患者共248次Af发作,心电触发因素中房性期前收缩占84.97%,窦性心动过缓占7.73%,心房扑动占2.14%,房性心动过速占2.57%;房性期前收缩来源于左心房上部占69.96%,左心房下部占12.02%,右心房上部占9.87%,右心房下部占3.86%;触发Af的房性期前收缩比未触发Af的房性期前收缩的联律间期缩短25ms以上;PAf发作存在23:00~1:00及9:00~11:00两个高峰,13:00~15:00一个低谷;PAf大多在短-长-短周期后发作,占62.23%,长-长-短周期后发作占21.89%。结论左心房上部房性期前收缩是PAf主要的触发因素,长-短周期现象是PAf发作的重要启动机制,自主神经失衡在PAf发作中起协同作用。动态心电图能对PAf治疗提供很大帮助。     

炎症与心房颤动相关性的研究进展

心房颤动(Af)是临床最常见的心律失常之一。目前对Af及其并发症(最重要是血栓形成)的有效治疗仍然是当前心律失常治疗中最薄弱的环节。Af的发病机制尚不完全明确。近年来大量临床和基础研究均提示炎症参与了Af的发生和发展。炎症与各种病理过程有关,如氧化应激、细胞凋亡、纤维化和促进Af基质形成。炎症还与内皮功能障碍、血小板活化、凝血酶联激活相关,这些均参与血栓形成过程。现对炎性介质及抗炎药物在Af中可能的作用机制及与Af的相关性综述如下。     

瘦素对高血压左心室肥厚患者预后的影响

高血压左心室肥厚(hypertensive-left ventricular hypertrophy,H-LVH)作为左室肥厚(LVH)最常见的因素之一,可使心血管疾病的发病率和死亡率均增加,近年来这类疾病引起了人们的高度重视。许多临床研究表明,原发性高血压患者的血清瘦素浓度明显升高,其机制可能与瘦素引起的交感神经系统(SNS)和肾素-血管紧张素-醛固酮系统(RAAS)的激活密切相关。而H-LVH发生的两大主要机制是SNS和RAAS的激活。因此,H-LVH与瘦素之间存在着关联。本文旨在总结H-LVH与瘦素之间的联系,并为治疗H-LVH并改善其预后提供新思路。     

直接肾素抑制剂在心血管疾病临床应用中的希望与前景

肾素-血管紧张素.醛固酮系统(RAAS)慢性持续激活是高血压、糖尿病、心血管病和肾脏病发生与发展的重要驱动因素,RAAS已成为干预上述疾病的主要病理生理目标. 在整个RAAS中,肾素是RAAS级联反应的起始和限速部位,对其作用的底物(血管紧张素原)具有高度的专一性和物种特异性.虽然血管紧张素Ⅱ是RAAS最重要的效应物质,但是整个RAAS活性的调节主要受肾素活性制约.     

心房颤动360例临床分析

目的了解心房颤动(Af)患者的病因分布特点与临床类型。方法1999-01-01-2003-12-31对浙江省人民医院因Af住院患者共360例进行回顾性分析。结果风湿性心脏瓣膜病(风心病)Af位居首位(31.9%)。非风湿性Af以冠心病与高血压为主。其中,阵发性Af60例(16.7%);持续性Af88例(24.4%);永久性Af212例(58.9%)。结论风心病、冠心病、高血压是房颤的主要病因,关注Af病因及临床分型,对治疗具有指导意义。     

肾素-血管紧张素-醛固酮系统与门静脉高压症

肾素-血管紧张素-醛固酮系统(RAAS)对血流动力学、水钠平衡等具有重要的调节作用。本文综述其在门静脉高压症发生发展中的作用和机制,以及拮抗RAAS在门静脉高压症治疗中的应用。     

肝硬化腹水治疗宜"限钠"与"补钠"交替应用

近期中华消化杂志(2007,27:330-333)对肝硬化腹水治疗的"限钠"争论,刊登了两篇观点不同的文章,读后有感而发. 针对传统限钠处理,两文观点不同.《重新认识和评价肝硬化腹水的几个问题》一文认为:①肾素-血管紧张素-醛固酮(RAAS)系统的激活是对低钠血症的一种生理保护性机制,限钠治疗并不能抑制RAAS活性,反而会增强RAAS活性,而纠正低血钠可以抑制RAAS活性.     

TGF-β1和CTGF联合检测对阵发性房颤患者的预测作用

心房纤颤(Af)的发病机制并未完全明确,但可以肯定的是触发因素和维持基质缺一不可.近年来研究显示,Af患者的心肌组织处于损伤与修复的动态变化中[1].越来越多的证据表明,心肌纤维化导致的心肌重构是Af能够维持的最重要原因[2].转化生长因子-β1( TGF-β1)和结缔组织生长因子(CT-GF)在心肌纤维化中起到关键作用[3,4].伴随着损伤后修复过程的发生,TGF-β1和CTGF的升高通常早于心肌纤维化导致的临床症状的出现且易于检测.本研究探讨血清TGF-β1、CTGF联合检测与自然发生的阵发性Af进展之间的关系.     

肾素-血管紧张素系统与心房颤动

心房颤动(AF)是一常见的心血管疾病,心房重构是AF维持和复发的主要机制,肾素-血管紧张素-醛固酮系统(RAAS)在心房重构中起重要作用.作用于RAAS的一些药物具有抑制心房重构的作用并减少AF的发作,给AF的治疗提供了一个新的思路.本文对RAAS在心房重构中的作用,及其拮抗剂对心房重构及AF的影响作一综述.     

肾素-血管紧张素系统与心房颤动

心房颤动(AF)是一常见的心血管疾病,心房重构是AF维持和复发的主要机制,肾素-血管紧张素-醛固酮系统(RAAS)在心房重构中起重要作用。作用于RAAS的一些药物具有抑制心房重构的作用并减少AF的发作,给AF的治疗提供了一个新的思路。本文对RAAS在心房重构中的作用,及其拮抗剂对心房重构及AF的影响作一综述。     

Angiotensin receptor blockers: evidence for preserving target organs

Hypertension is a major problem throughout the developed world. Although current antihypertensive treatment regimens reduce morbidity and mortality, patients are often noncompliant, and medications may not completely normalize blood pressure. As a result, current therapy frequently does not prevent or reverse the cardiovascular remodeling that often occurs when blood pressure is chronically elevated. Blockade of the renin-angiotensin system (RAS) is effective in controlling hypertension and treating congestive heart failure. Both angiotensin-converting enzyme (ACE) inhibitors and angiotensin receptor blockers (ARBs) inhibit the activity of the RAS, but these two classes of antihypertensive medications have different mechanisms of action and different pharmacologic profiles. Angiotensin-converting enzyme inhibitors block a single pathway in the production of angiotensin II (Ang II). In addition, angiotensin I is not the only substrate for ACE. The ACE inhibitors also block the degradation of bradykinin that may have potential benefits in cardiovascular disease. Bradykinin is, however, the presumed cause of cough associated with ACE inhibitor therapy. Data from clinical trials on ACE inhibitors serve to support the involvement of the RAS in the development of cardiovascular disease. Angiotensin receptor blockers act distally in the RAS to block the Ang II type 1 (AT1) receptor selectively. Thus, ARBs are more specific agents and avoid many side effects. Experimental and clinical trials have documented the efficacy of ARBs in preserving target-organ function and reversing cardiovascular remodeling. In some instances, maximal benefit may be obtained with Ang II blockade using both ARBs and ACE inhibitors. This review describes clinical trials that document the efficacy of ARBs in protecting the myocardium, blood vessels, and renal vasculature.     

Angiotensin II blockade: a therapeutic strategy with wide applications

Evidence now exists suggesting a pathologic role for angiotensin II in patients with cardiovascular disease and those with risk factors. Clinical trials such as the Losartan Intervention for Endpoint Reduction in Hypertension Study (LIFE), the Heart Outcomes Prevention Evaluation Study (HOPE), the African American Study of Kidney Disease and Hypertension (AASK), and the Reduction of Endpoints in NIDDM with the Angiotensin II Antagonist Losartan (RENAAL) study have clearly demonstrated that blood pressure reduction is important in hypertension and diabetes. If this can be accomplished with agents that block the renin-angiotensin system, then additional clinical benefit will be achieved. Clinical data on angiotensin-converting enzyme inhibitors (ACEIs) are well established, while emerging data on the use of angiotensin II receptor blockers (ARBs) continue to grow. There is evidence supporting the concept of angiotensin II escape in the presence of ACEIs. The question that remains to be answered is whether a combination of both agents (ACEIs and ARBs) can improve clinical outcomes. Ongoing clinical trials will answer this question.     

食管心房调搏诱发阵发性房颤的心房电生理特性

为了探讨食管心房调搏对阵发性房颤检查的临床价值。回顾食管心房调搏诱发２５例阵发性房颤的心房电生理特性。其结果；程序刺激，分级起搏诱发１１例房颤，均有明确的房颤 史，猝发电脉冲诱发的１４例中１０例有明确的房颤史。房颤组２５例与正常对照组２５例相比心房有效不应期缩短，相对不应期区域扩大，最大房间传导时间延长，房间传导延缓更显著，这些可能是食管心房调搏诱发房颤的重要电生理基础。认为食管心房调搏对确定临床     

Efficacy of Angiotensin Receptor Blockers in Cardiovascular Disease

The cardiovascular continuum describes the progression of pathophysiologic events from cardiovascular risk factors to symptomatic cardiovascular disease (CVD) and life-threatening events. Pharmacologic intervention early in the continuum may prevent or slow CVD development and improve quality of life. The renin–angiotensin–aldosterone system (RAAS) is central to the pathophysiology of CVD at many stages of the continuum. Numerous clinical trials of angiotensin converting enzyme (ACE) inhibitors and angiotensin receptor blockers (ARBs) have shown that RAAS blockade provides benefits to patients across the continuum. ARBs are as effective as ACE inhibitors in the treatment of hypertension; however tolerability and adherence to therapy appear to be improved with ARBs. Large clinical trials have shown that ARBs may provide therapeutic benefits beyond blood pressure control in patients with diabetes, heart failure or at risk of heart failure following a myocardial infarction. In addition, ARBs have been shown to provide protective effects in patients with impaired renal function or left ventricular hypertrophy. Additional clinical trials are ongoing to further characterize the role of ARBs in CVD management.     

心房颤动自主神经机制与神经节消融

心房颤动（房颤）的发生机制,除了局灶学说和多发子波折返学说,大量的基础和临床研究证实,心脏内源性自主神经系统在房颤的发生和维持中起着重要作用,针对于心脏自主神经的神经节消融为治疗房颤提供了新的发展方向。     

Angiotensin converting enzyme inhibitor and angiotensin receptor blockade use in relation to outcomes in anticoagulated patients with atrial fibrillation

BACKGROUND: The renin-angiotensin-aldosterone-system (RAAS) plays an important role in atrial fibrillation (AF). Evidence shows that blocking the RAAS with angiotensin converting enzyme inhibitors (ACEIs) and angiotensin receptor blockers (ARBs) has a definite role in preventing new onset AF and in maintaining sinus rhythm in recurrent AF. Our aim was to determine if ACEI/ARB treatment was associated with clinical outcomes [stroke/systemic embolic events (SEE), mortality] in a controlled, anticoagulated AF population. METHODS: An ancillary retrospective cross-sectional and longitudinal analysis of participants in the Stroke Prevention using an ORal Thrombin Inhibitor in AF (SPORTIF) III and V trials, in relation to use (or nonuse) of ACEI/ARBs. RESULTS: Rates of stroke/SEEs, mortality or major bleeding were no different between users and nonusers in the whole cohort, or in relation to the presence/absence of hypertension, coronary artery disease and previous stroke/transient ischaemic attack, nor amongst those aged <75 years. Patients aged > or = 75 years taking ACEIs or ARBs had lower mortality (HR 0.71, 95% CI 0.52-0.95), but no significant influence on other end-points was noted. Diabetics and those with left ventricular dysfunction on ximelagatran had a higher odds ratio of abnormal liver enzyme levels. There was no apparent benefit of ACEIs or ARBs on other event rates. CONCLUSIONS: This analysis from two large randomized trials of anticoagulation has not demonstrated a significant benefit of ACEI or ARB use amongst AF patients, except amongst elderly subjects.     

血管紧张素Ⅱ受体阻滞剂与神经保护

血管紧张素Ⅱ受体阻滞剂(ARB)通过阻滞1型血管紧张素Ⅱ受体(AT1受体)降低血压、逆转血管重构,激活2型血管紧张素Ⅱ受体(AT2受体)以提高血管紧张素Ⅱ(AngⅡ)水平扩张血管、抗增殖及调脂.进一步了解ARB在神经保护中的作用机制,可为临床治疗缺血性卒中提供新的思路.     

ACE-Inhibition and Angiotensin II Receptor Blockers in Chronic Heart Failure: Pathophysiological Consideration of the Unresolved Battle

Reducing the effects of angiotensin II by blockade of AT1-receptors may be superior to inhibition of angiotensin II formation by angiotensin converting enzyme (ACE) inhibitors in chronic heart failure (CHF) patients. However, the results of several trials did not fulfil this expectation. In both ELITE II with symptomatic CHF patients and in OPTIMAAL involving high risk patients after acute myocardial infarction, angiotensin II type I (AT1) receptor blocker (ARB) losartan did not prove to be superior to captopril. There are several potential reasons, why ARBs did not fare better than ACE inhibitors. Although AT1-receptor blockade may block the effects of non-ACE pathways of tissue angiotensin II formation, no clinical evidence is available that a more powerful inhibition of the tissue renin-angiotensin system brings improved survival. The choice of patients for clinical trials of HF therapy is not based on the level of neurohumoral activation. Thus, the more effective attenuation of angiotensin II action with ARBs may not bring additional benefits. The potential antiremodeling effect of ARBs through the stimulation of AT2 receptors by angiotensin II could be counterbalanced by a failure of AT1-receptor blockers to enhance bradykinin, nitric oxide and prostacyclin formation with antigrowth properties. Although ACE-inhibitors seem to have slightly better results at present than AT1 blockers in the battle on heart failure patient, future trials will decide which is the definitive winner.     

自主神经介导性心房颤动研究进展

自主神经系统在心房颤动的触发和维持中扮演了重要的角色,因此心房颤动发病机制中的神经源性理论引起越来越多的关注,深入研究心房颤动与自主神经的关系对认识心房颤动的机制及指导治疗很有意义。针对神经节的靶向治疗可提高心房颤动射频消融的成功率并较少复发,正成为新的治疗方法。神经节消融对正常心肌组织创伤较小,但定位神经节的最好方法仍有争议。     

血管紧张素受体拮抗剂治疗高血压

肾素-血管紧张素-醛固酮系统（RAAS）是调节血压的主要机制,也是治疗高血压病的重要靶点。血管紧张素受体拮抗剂（ARBs）,通过阻滞特异性血管紧张素受体,干扰RAAS的活性,成为治疗高血压的一线药物。临床结果显示ARBs作为单用药或联合其他降压药物治疗高血压有其特殊的优势。在降压方面,与血管紧张素转换酶抑制剂和其他类型的降压药物相比,ARBs具有良好的耐受性而适合用于治疗更广泛的患者。最近研究结果显示在12个月期间使用ARBs治疗高血压依从性明显高于其他降压药物,而且副作用少。具备临床有效性和良好耐受性的ARBs药物,可以作为治疗高血压的主要药物。