急性前壁心肌梗死并发束支阻滞的近期与远期预后

156例急性前壁心肌梗死.其中36例并发束支阻滞(A 组).120例无束支阻滞(B 组)。心律失常的发生率 A 组77.7%.B 组45.8%(P>0.05).住院病死率 A 组14.0%.B 组4.8%有显著差异(P<0.01)。     

Prognostic significance of bundle-branch block in acute myocardial infarction: the importance of location and time of appearance

BACKGROUND: The presence of bundle-branch block (BBB) is associated with high mortality rates and is considered an important predictor of poor outcome in patients with acute myocardial infarction (AMI). HYPOTHESIS: The objective of this study was to assess the prognostic significance of BBB in patients with AMI depending on its form of presentation. METHODS: A multicenter prospective 1-year follow-up study involving 1,239 consecutive patients diagnosed with AMI was performed. RESULTS: Bundle-branch block was present in 177 cases (14.2%), associated with worse clinical characteristics, lower rate of thrombolytic therapy, and higher mortality: in-hospital (23.8 vs. 9.7%, p < .01) and 1-year (40.9 vs. 16.9%, p < 0.01). Compared with right BBB (n = 135), left BBB (n = 42) was more often associated with female gender and higher prevalence of cardiovascular diseases, but had a similar 1-year mortality. In the absence of heart failure or complete atrioventricular (AV) block, there was no difference in in-hospital mortality of patients with BBB (n = 76) and without BBB (n = 786) (2.6 vs. 3.9%). Compared with existing BBB (n = 113), BBB of new appearance (n = 64) was more often accompanied by complete AV block and heart failure and higher in-hospital and 1-year mortality rates. Only BBB of new appearance was an independent predictor of mortality: in-hospital (odds ratio [OR] 2.3, 95% confidence interval [CI] 1.1-4.7) and 1-year mortality (OR 3.2, 95% CI, 1.7-9.1). CONCLUSIONS: In patients with AMI, the classification of BBB according not only to location but also to time of appearance is of practical interest. New BBB is an independent predictor of short- and long-term mortality.     

Right bundle-branch block unmasking a myocardial infarction

A patient with an acute anteroseptal myocardial infarction and intermittent right bundle-branch block is presented. Abnormal Q waves in right precordial leads were only observed during right bundle-branch block. In the absence of right bundle-branch block, depolarization of the right ventricular free wall concealed the abnormal Q waves typical of an anteroseptal infarct. Right bundle-branch block, by preventing early activation of the right ventricular free wall, facilitated the correct diagnosis and localization of the infarction.     

急性心肌梗死合并三度房室传导阻滞的预后及再灌注治疗的意义

目的分析急性心肌梗死合并三度房室传导阻滞(Ⅲ°AVB)患者的临床特征,探讨再灌注治疗对急性心肌梗死合并Ⅲ°AVB预后的意义。方法1992年~2005年连续入院的急性心肌梗死合并Ⅲ°AVB患者51例(Ⅲ°AVB组),每组选择前后相继入院的急性心肌梗死患者2例,共102例构成非Ⅲ°AVB组。比较两组基线临床资料、住院期间死亡率、并发症,以及再灌注治疗的差异。观察Ⅲ°AVB组12h内有效再灌注治疗的病例和未能再灌治疗的病例住院期间的转归。结果(1)与非Ⅲ°AVB组比较,Ⅲ°AVB组发病年龄较大,下壁或右心室梗死比例高,住院期间死亡、心室颤动、KillipⅣ级心功能、心源性休克发生率高,需要起搏治疗的例数多,两组差异有统计学意义。(2)Ⅲ°AVB组排除既往有心肌梗死史及合并其他全身疾病的病例5例,其余46例,17例发病12h内再灌注治疗,住院期间死亡1例,29例未再灌注治疗,死亡12例,P<0.02.。结论急性心肌梗死合并Ⅲ°AVB预后差,住院期间死亡率高。12h内再灌注治疗患者住院期间死亡例数相对较少,这种预后的差异是否有普遍意义,还需进一步研究。     

Correlates of bundle-branch block in patients undergoing primary angioplasty for acute myocardial infarction.

BACKGROUND: Early reperfusion therapy has reduced the infarct size and mortality rate in patients with acute myocardial infarction (AMI). The occurrence of bundle-branch block in AMI is related to the amount of myocardial damage and the insult to the conduction system. HYPOTHESIS: To evaluate the clinical and angiographic factors related to the occurrence of bundle-branch block (BBB) in patients with primary percutaneous transluminal coronary angioplasty (PTCA), we investigated consecutive series of patients with their first Q-wave AMI and successful PTCA. METHODS: Coronary angiogram at the time of admission, electrocardiogram, and echocardiogram were evaluated in 279 patients with their first Q-wave AMI and successful PTCA. RESULTS: Bundle-branch block was detected in 26 patients (9%); 16 patients had transient and 10 patients had persistent block, while 16 patients had bifascicular block and 10 patients had right BBB. The patients with BBB had a significantly larger number of left ventricular asynergic segments, higher incidence of total occlusion of infarct-related artery, angiographic no reflow, and pericardial rub than those without BBB. When the multivariate analysis was performed using five clinical markers of infarct severity, angiographic no reflow (F = 20.2, p < 0.001) and total occlusion of infarct-re-lated artery (F = 4.2, p = 0.04) were found to be the significant variables related to BBB. CONCLUSIONS: Despite successful primary PTCA, absence of antegrade flow in the infarct-related artery at the onset of AMI and/or angiographic no reflow resulted in more severe transmural myocardial damage and, hence, the occurrence of BBB.     

Bundle branch block in acute Q wave inferior wall myocardial infarction: A high risk subgroup of inferior myocardial infarction patients

The aim of this study was to determine the incidence and impactof right and left bundle branch block on the in-hospital, 5-yearand 10-year mortality of patients with acute inferior Q wavemyocardial infarction. A retrospective analysis of clinicalcharacteristics, hospital, 1-, 5-, and 10-year mortality of2215 consecutive patients with acute inferior Q wave myocardialinfarction hospitalized in 13 coronary care units in Israelwas performed Bundle branch block during acute Q wave inferior wall myocardialinfarction was present in 108 patients (4.9%), 85 of whom hadright and 23 left bundle branch block. Patients with bundlebranch block had more in-hospital complications than those without,irrespective of the site and time of appearance of the block.In addition, a trial fibrillation (19%), complete atrioventricularblock (21%) and congestive heart failure (45%) appeared morefrequently in patients with, than in those without, bundle branchblock (11%, 9% and 31%, respectively), and in-hospital and 5-yearmortality were higher in patients with the block (22%, 33%)than in those without it (13% and 23%, respectively). Bundle branch block emerged as an independent predictor of deathonly among patients with new right bundle branch block, andright bundle branch block emerged as an independent predictorfor the development of complete atrioventricular block (oddsratio 2.13; 90% confidence interval 1.39–3.28). However,hospital mortality among patients with inferior myocardial infarctionand complete atrioventricular block was virtually independentof bundle branch block (39% with vs 36% without bundle branchblock, respectively). Patients with inferior Q wave myocardial infarction and bundlebranch block comprise a high risk subgroup of patients witha complicated hospital course and increased hospital and long-termmortality.     

The prognostic importance of creatinine clearance after acute myocardial infarction.

AIMS: The purpose of this study was to assess renal dysfunction as an independent predictor of mortality after acute myocardial infarction. METHODS: The study population was 6252 patients with a myocardial infarction admitted alive from 1990 to 1992. The mortality status was obtained after at least 6 years. RESULTS: Cox proportional-hazards model demonstrated that the unadjusted risk ratio associated with a calculated creatinine clearance < or =40 ml x min(-1) compared to a clearance above 85 ml x min(-1) was 7.1 (95% confidence interval 6.2-8.0). Adjustment for multiple available covariates reduced this risk to 2.0 (1.6-2.4). The unadjusted risk ratio associated with clearance from 41 to 55 ml x min(-1) and from 71 to 85 ml x min(-1) was 3.7 (3.3-4.2) and 1.5 (1.3-1.7) respectively, but after adjustment for all available variables these risks were reduced to 1.4 (1.2-1.6) and 1.1 (0.9-1.3) respectively. CONCLUSION: Renal dysfunction is an important risk factor after acute myocardial infarction. When the risk is adjusted for available competing risk factors only severely reduced renal function is associated with an important and independent risk of mortality after acute myocardial infarction. The risk of a moderate reduction in renal function is almost fully explained by an association with other conditions.     

Abnormal signal-averaged electrocardiograms in patients with incomplete right bundle-branch block

Background and hypothesis: A hypothesis was formulated that regional delayed activation of the right ventricle, as seen in incomplete right bundle-branch (IRBBB) aberrancy, may simulate late potential activity and may be responsible for abnormal signal-averaged electrocardiograms (SAECGs). No previous studies have specifically addressed this issue in this particular group of patients (with IRBBB). Therefore, the aim of the present study was to investigate the incidence of abnormal SAECGs in patients with IRBBB. If this were confirmed, our purpose would further be to investigate ways of reducing the false positive results. Methods: The study group included 53 patients (28 men and 25 women), aged 53 ± 13 years, with no history of previous myocardial infarction or ventricular tachycardia and who had an electrocardiogram (ECG) showing IRBBB. An SAECG was also performed in a control group of 19 age-matched individuals with a normal ECG. Time domain analysis was performed using a band pass filter of 40–250 Hz. The following parameters were considered normal: filtered QRS duration (QRSD) < 114 ms, root mean square of the voltage of the last 40 ms of the QRS complex (RMS) > 20 μV, and the duration of the low amplitude signal (< 40 μV) at the terminal portion of the QRS (LAS) < 38 ms. An SAECG was considered abnormal if any two of these criteria were abnormal. Results: The mean values of the SAECG parameters were: QRSD 101 ± 11 ms, RMS 32 ± 20 μV, LAS 32 ± 12 ms, and noise 0.29 ± 0.13 μV. Abnormal SAECGs with at least two criteria satisfied were present in 16 of 53 (30%) patients compared with 0 (0%) of 19 individuals in the control group (p = 0.02). Abnormal values included the combination of RMS and LAS in 12 patients and all three parameters in 4 patients. However, if the definition of late potentials were limited to the combination of abnormal QRSD and either RMS or LAS values, the incidence of false positive results (4 patients) (7.5%) would be significantly decreased (p = 0.007). At 21 months of follow-up, no arrhythmic events occurred. Conclusions: Delayed terminal conduction observed in IRBBB may cause a high incidence of false positive late potentials on SAECGs. Based on this study, we propose that this can be largely remedied if the optimal criteria for the presence of late potentials in patients with IRBBB always include the combination of QRSD and either RMS or LAS.     

Prognostic importance of complete atrioventricular block complicating acute myocardial infarction

Third-degree atrioventricular block after acute myocardial infarction is considered to have prognostic importance. However, its importance in conjunction with thrombolytic therapy and its relation to left ventricular function remains uncertain. This report also outlines an important distinction between atrioventricular block in the setting of anterior and inferior wall acute myocardial infarction, with profound clinical and prognostic implications.     

Occurrence of complete heart block associated with acute renal infarction

Complete heart block (CHB) and acute renal infarction (ARI) are both uncommon diseases and seldom encountered in the clinical practice. We describe a rare case of pre‐existing left bundle branch block, presenting simultaneously with CHB and ARI. The possible mechanism depends on prior presence of either CHB or ARI. If ARI occurs first, severe pain and embolism may enhance the vagal tone resulting in decrease in the heart rate and transient intraventricular conduction interruption, which subsequently causes CHB. The opposite scenario, CHB preceding ARI, is also possible. CHB can be physiologic and transient, with higher risk of development in the circumstance of pre‐existing conduction system disturbances. Patients with CHB are predisposed to formation of thrombi and thromboemboli, giving rise to ARI. In conclusion, awareness and timely identification of the clinical manifestations of these two diseases may facilitate early diagnosis and prompt management.     

A complete right bundle-branch block masking Brugada syndrome

A 69-year-old man without structural heart disease was admitted for syncope. His electrocardiogram displayed complete right bundle branch (CRBBB). A coved type ST elevation was observed with transient normalization of CRBBB giving rise to a normal QRS. These findings suggest that Brugada syndrome can be masked by CRBBB.     

急性心肌梗死并发心房颤动/心房扑动的影响因素及预后分析

目的分析急性心肌梗死(AMI)患者合并心房颤动(atrial fibrillation,Af)/心房扑动(atria flutter,AF)的发病率、临床特点、影响因素及其对院内死亡的影响。方法将我院收治的653例AMI患者分为Af/AF组(61例)及无Af/AF组(592例),分析发生Af/AF的相关危险因素;再根据是否在院内死亡分为院内死亡组(64例)及未死亡组(589例),评估Af/AF对AMI患者院内死亡的影响。结果AMI患者初发Af/AF的发生率为9.3%。单因素分析显示,Af/AF组与无Af/AF组在年龄、性别、入院时心率、心肌梗死范围、Killip分级、左心室射血分数、入院时血肌酐水平及血红蛋白水平均有显著性差异(P<0.05)。Af/AF组与无Af/AF组多因素logistic回归分析显示,多部位心肌梗死、女性是影响AMI患者发生Af/AF的最主要独立危险因素;院内死亡组与未死亡组多因素lo-gistic回归分析显示,Af/AF是影响AMI患者院内死亡的独立危险因素。结论Af/AF是AMI患者常见的并发症,合并Af/AF的患者住院期间的预后更差。     

Reverse left septal activation during intermittent left bundle-branch block: Indirect proof for concealed retrograde left bundle-branch activation

Concealed retrograde activation of bundle branch has been often proposed for explaining the persistence of functional rate-dependent bundle-branch block, but direct proof of such a mechanism in man has rarely been demonstrated. We report intracardiac recordings compatible with a reversal of activation of the left basal interventricular septum during intermittent left bundle-branch block. In our case, however, retrograde activation into the left bundle-branch cannot be recordable, probably due to the concealment within the muscular septal activation, even if this may explain the perpetuation of bundle-branch block according to the linking phenomenon.     

QTc intervals in acute myocardial infarction: First-year prognostic implications

Corrected QT (QT_c) intervals were measured retrospectively in 160 consecutive survivors of acute myocardial infarction under 66 years of age. Calculations were made the first 2 d in the coronary care unit (CCU), the first post-CCU day, at discharge, and at 1–3, 6, and 12 months after discharge. All patients were in sinus rhythm and without bundle branch block at discharge from the hospital. Sixteen patients died during the first follow-up year. Twenty patients suffered a reinfarction, five of whom died. The highest QT_c values were registered in the CCU and the lowest at the 1-year control. Patients with subendocardial infarcts had longer QT_c intervals than those with transmural infarcts, especially during the acute phase. Patients with inferior infarcts had shorter QT_c intervals during the CCU period. Those who reinfarcted or died a cardiac death (particularly when sudden) during the follow-up year had longer QT_c intervals during the post-CCU phase. A multivariate analysis of risk factors revealed that the QT_c interval at discharge was of significant independent value for predicting major cardiac events after discharge from the hospital. It is concluded that repeated measurements of QT_c may be of value when assessing prognosis after acute myocardial infarction.     

急性下壁心肌梗塞中右室心肌梗塞与房室传导阻滞的关系

目的 探讨急性下壁心肌梗塞(MI)并发右室MI与发生房室传导阻滞的关系.方法 共有120例确诊急性下壁MI的住院患者,根据是否发生房室传导阻滞分为房室传导阻滞组(AVB)和非房室传导阻滞(NAVB)组;是否合并右室MI,则分为右室MI(RVI)组和非右室MI(NRVI)组.结果 急性下壁MI并发AVB组住院死亡率明显高于NAVB组(P<0.05);合并RVI患者,其AVB的发生率明显高于NRVI病人(P<0.01).合并RVI及高血压组患者,其AVB的发生率最高,明显高于RVI组(P<0.05).结论 右室心肌MI是急性下壁心肌MI发生AVB的重要原因之一.     

再灌注治疗对急性心肌梗死合并Ⅲ度房室传导阻滞患者预后的影响

目的对比研究不同再灌注治疗对急性心肌梗死（AMI）合并Ⅲ度房室传导阻滞（Ⅲ。AVB）患者预后的影响。方法2007年1月至2012年1月住院的AMI合并111。AVB患者69例,分为对照组、溶栓组和介入组,比较三组患者心源性休克、恶性心律失常、心衰等发生率和总死亡率。于再灌注治疗后6个月对存活者行心脏超声检查,测定左室射血分数（LVEF）和左室舒张末期内径（LVD）。结果①介人组再灌注治疗后心源性休克、恶性心律失常、心衰等发生率和总死亡率均明显低于溶栓组及对照组,溶栓组亦明显低于对照组,差异均有统计学意义（P〈0．05）。②6个月后三组存活者行心脏超声心动图检查,介入组LVEF明显高于溶栓组及对照组（P〈0．05）,LVD明显低于溶栓组及对照组（P〈0．05）。结论AMI合并Ⅲ。AVB预后差,住院期问心源性休克、恶性心律失常、心衰等发生率和死亡率高。AMI后行急诊再灌注能改善左心功能和预后,行急诊冠脉介入治疗较静脉溶栓治疗效果更为突出。     

Delay time in suspected acute myocardial infarction and the importance of its modification

This paper summarizes the present knowledge of delay time in suspected acute myocardial infarction. More than 50% of deaths in acute myocardial infarction occur outside of the hospital setting. Recent experiences indicate that early and even late mortality can be dramatically reduced by intervention in the early phase. This points up the importance of bringing patients with suspected acute myocardial infarction to the hospital as early in the course of MI as possible. The predominating cause of delay is the time it takes for the patient to decide to go to hospital regardless of a previous history of cardiovascular disease. Patients arriving in hospital in later stages of MI are at a very high risk of mortality. Therefore one of the most important problems to be resolved is how to reduce delay time in suspected acute myocardial infarction. Such efforts have been surprisingly few. Limited experiences indicate that public education can reduce delay time dramatically.     

急性心肌梗死并发房室传导阻滞的临床分析

目的探讨急性心肌梗死(AMI)患者发生房室传导阻滞(AVB)的临床特点。方法采用非创伤性心电监测法监测122例心肌梗死患者AVB的发生率及其对药物治疗反应、演变过程和最终预后。结果 122例AMI患者中20例发生AVB(16.4%)。17例发生于下/后心肌梗死者,3例发生于前壁/广泛前壁心肌梗死者。按AVB发生的不同时期分为早发组(发病8 h内,n=8)和晚发组(发病8 h后,n=12),晚发组并发症显著高于早发组(25﹪vs 83.3﹪,P<0.05);早发组对阿托品或山莨菪碱治疗反应较好(P<0.05);早发组Ⅲ度AVB 7例、Ⅱ度AVB 1例,持续时间短。晚发组Ⅰ度AVB 5例、Ⅱ度AVB 6例、Ⅲ度AVB 1例,持续时间长;早发组住院期间死亡1例、晚发组死亡5例,有显著差异(P<0.05)。结论 AMI病人中下/后壁心肌梗死易并发AVB;8 h之内发生的AVB以Ⅲ度AVB为主,早期发生的AVB患者预后好。     

Prognostic importance of previous myocardial infarction in patients receiving thrombolytic therapy for acute infarction

This study evaluated the prognostic significance of reinfarction location by considering the previous site or type of myocardial infarction (MI) among 1601 patients with a history of previous MI who took part in the International (non-Italian) tPA/STK trial and/or the Israeli GUSTO study population. These patients were accordingly divided and hospital mortality was compared by six location groups as follows: acute inferior with previous inferior (8.1% hospital mortality), acute inferior with previous anterior (12.8%), acute anterior with previous inferior (13.3%), acute anterior with previous anterior (11.1%), acute inferior with previous non-Q-wave MI (7.6%), and acute anterior with previous non-Q-wave MI (11.2%) (p = 0.17 for comparison between the six groups). Hospital mortality tended to increase among patients with an anterior reinfarction compared with those with an inferior one (12.1% vs. 9.5%, p = 0.12). Among patients with a reinfarction at a different ECG location from the previous event, mortality tended to be higher compared with patients with two MIs at the same location (13.1% vs. 9.7%, p = 0.07). Recurrent MI following a previous Q-wave MI did not cause a higher mortality compared with a previous non-Q-wave type of MI (11.5% vs. 9.5%, p = 0.24). Among patients sustaining reinfarction, overall mortality did not differ between STK- and tPA-treated patients (11.0% vs. 11.4%, p = NS). In conclusion, the current study identified trends for higher mortality rates in patients with anterior compared with inferior reinfarction, with remote compared with the same ECG location of the two infarctions but not following a previous non-Q-wave compared with Q-wave MI. However, no particular combination of successive MIs location was significantly associated with a higher risk for hospital mortality.     

完全性房室阻滞在急性下壁心肌梗死合并及不合并右室梗死病人的预后意义

目的　确定完全性房室阻滞（ＣＡＶＢ）对急性下壁心肌梗死（ＡＩＭＩ）伴有或不伴有右室梗死（ＲＶＩ）病人预后的影响。方法　分析２６５ 例ＡＩＭＩ病人临床资料,２２２ 例无合并ＲＶＩ的病人（Ⅰ组）,４３例合并ＲＶＩ病人（Ⅱ组）,根据住院期间有无合并ＣＡＶＢ再将其分为两个亚组（无合并ＣＡＶＢ组（Ⅰａ、Ⅱａ组）及合并ＣＡＶＢ组（Ⅰｂ、Ⅱｂ 组））。选择临床及实验室资料进行比较。结果　（１）ＡＩＭＩ合并ＣＡＶＢ明显增加心脏并发症的发生率,Ｐ＜ ０．０１;ＡＭＩ合并ＲＶＩ虽有增高趋势,但无显著性差异;（２）溶栓治疗显著降低ＡＩＭＩ住院期间死亡率,特别是ＡＩＭＩ同时合并ＲＶＩ和ＣＡＶＢ的病人,Ｐ＜ ０．０５;（３）与ＣＡＶＢ、ＲＶＩ并存的ＡＩＭＩ以心脏合并症及ＣＫ峰值居高,住院死亡率显著为特点。结论　ＡＩＭＩ合并ＣＡＶＢ及ＲＶＩ表现出极高的心脏合并症发生率及住院死亡率可能是梗面积较大的结果,但是ＲＶＩ及ＣＡＶＢ的协同作用可能是影响ＡＩＭＩ预后的另外因素。