Dipyridamole thallium-201 scintigraphy for improved detection of left anterior descending coronary artery stenosis in patients with left bundle branch block

In patients with left bundle branch block (LBBB) undergoingthallium-201 exercise scintigraphy septal perfusion defectsare frequently observed irrespective of the presence or absenceof coronary artery disease. Consequently, in these patientsthe specificity for detecting stenoses in the left anteriordescending coronary artery (LAD) by thallium-201 scintigraphyis relatively low. It has been hypothesized that pharmacologicalvasodilation would result in higher specificity than conventionalexercise thallium-201 scintigraphy because of a more uniformexploitation of coronary flow reserve. Twenty-five consecutive patients with LBBB underwent dipyridamolethallium-201 imaging and coronary arteriography within 3 months.The prevalence of coronary artery disease was estimated at 48±19%.Sensitivity for detection of LAD lesions was 100% and specificitywas 88%. The positive predictive accuracy and the negative predictiveaccuracy were 80% and 100% respectively. The ‘false positive’septal defects were of the non-reversible type. The appearanceof septal perfusion defects was not dependent on changes inheart rate during dipyridamole infusion. This study indicatesthe value of dipyridamole thallium-201 imaging for non-invasivedetection of LAD stenosis in patients with LBBB.     

完全性左束支阻滞和右束支阻滞心电图结果分析

目的 了解完全性左束支阻滞和右束支阻滞不同性别、不同年龄的发生率情况.方法 分析108 610例常规心电图检测结果,分别统计完全性左束支阻滞和右束支阻滞不同性别、不同年龄的发生率情况.结果 108 610例门诊及住院患者资料,完全性左束支阻滞19例,占0.18％;右束支阻滞3 794例,占3.49％;完全性左束支阻滞发生率在不同性别之间差异无统计学意义（Х^2=1.707,P=0.191）,不同年龄之间比较差异有统计学意义（Х^2=209.874,P＜0.05）;右束支阻滞发生率在不同性别之间、不同年龄之间比较,差异均有统计学意义（Х^2=986.046,P＜0.05;Х^2=1 483.286,P＜0.05）.结论 60岁以上老年人的完全性左束支阻滞和右束支阻滞发生率较高,应定期进行常规心电图检查,及时发现异常情况并进行相应的处理.     

Recurrent extensive anterior myocardial infarction with left and right bundle branch block

The diagnosis of myocardial infarction with left bundle branch block is difficult. We report a case of 56‐year‐old man with old extensive anterior myocardial infarction and left bundle branch block (masked each other). The recurrent myocardial infarction indicated right bundle branch block and first‐degree atrioventricular block, making a clear diagnosis of complicated and interesting ECG.     

完全性左束支阻滞81例临床分析

目的分析完全性左束支阻滞(CLBBB)病例的临床特点。方法回顾性分析81例完全性左束支阻滞患者的病因、动态心电图、超声心动图、冠状动脉造影结果。结果60岁以上男性43例,占53%。病因以冠心病、高血压、心功能不全多见。本组冠脉造影的28例完全性左束支阻滞患者中确诊为冠心病者16例,占57.14%。超声心动图结果:55%患者心房、心室增大或心房心室同时增大。左室射血分数(LVEF)<50%者22例,占33.8%。动态心电图检查可见左束支阻滞常合并各种类型心律失常。结论完全性左束支阻滞常发生在老年男性患者,常见于器质性心脏病,尤其是冠心病、高血压、扩张型心肌病。完全性左束支阻滞可导致不良的心脏血流动力学效应,导致左心室功能受损。     

Usefulness and limitations of dobutamine-atropine stress echocardiography for the diagnosis of coronary artery disease in patients with left bundle branch block. A multicentre study.

BACKGROUND: Patients with left bundle branch block exhibit abnormal septal motion which may limit the interpretation of stress echocardiograms. This study sought to assess the diagnostic value of dobutamine-atropine stress echocardiography in left bundle branch block patients. METHODS AND RESULTS: Sixty-four left bundle branch block patients (mean age 59 years, 24 men) with suspected coronary artery disease underwent dobutamine-atropine stress echocardiography and coronary arteriography. Myocardial ischaemia was defined as new or worsening wall thickening abnormalities. Coronary artery disease was quantitatively defined as a diameter stenosis >/=50% in a major epicardial artery. Rest septal motion was normal (apart from the early systolic septal notch) in 34 patients (53%) and abnormal in 30 patients (47%). Rest septal thickening was normal in 32 patients (50%) and abnormal in 32 patients (50%). All seven patients with a QRS duration >/=160 ms and an abnormal QRS axis had abnormal rest septal motion and thickening. Inter-observer agreement for ischaemia was 88%. In all but one patient disagreement was in the septum. For the anterior and posterior circulation, respectively, sensitivity was 60% (9/15) and 67% (8/12), specificity was 94% (46/49) and 98% (51/52), and accuracy was 86% (55/64) and 92% (59/64). Sensitivity for the anterior circulation tended to be better in patients with normal rest septal thickening (83% vs 44%). CONCLUSIONS: Dobutamine-atropine stress echocardiography has excellent diagnostic specificity in left bundle branch block patients with suspected coronary artery disease. In patients with abnormal rest septal thickening, however, dobutamine-atropine stress echocardiography may lack good sensitivity for detection of coronary artery disease in the anterior circulation. Left bundle branch block patients who potentially most benefit from dobutamine-atropine stress echocardiography may initially be selected by their resting electrocardiogram.     

Left bundle branch block: a hemodynamic and angiographic study

Coronary angiography, left ventriculography, and hemodynamicdata were evaluated in 34 patients with coronary artery diseaseand left bundle branch block. Left axis deviation (mean frontalaxis greater than —30°) was correlated with hemodynamicand angiographic findings. The patients with left bundle branchblock and coronary artery disease were compared with 98 subjectswith ischemic heart disease without conduction disturbances. Left axis deviation, which is common in subjects with coronaryartery disease and left bundle branch block, had no prognostichemodynamic significance. Left bundle branch block associatedwith coronary artery disease did not imply more severe or moreextensive coronary atherosclerosis, even though it revealeda higher frequency of lesions of the left main coronary arteryand more severe myocardial dysfunction, with asynergy especiallyinvolving the anterior areas of the left ventricle.     

左束支传导阻滞的核素心肌显像

目的探讨左束支传导阻滞的核素心肌显像并对照冠状动脉造影诊断冠心病的临床意义。方法15例左束支传导阻滞患者与10例正常人对照,先行多巴酚丁胺负荷试验再静脉注射201TI和99mTc-MIBI双核素心肌显像并与9例冠状动脉造影者进行比较,分析诊断冠心病的可靠性。在核素心肌显像中,分别对图像的中间短轴断层面进行定量分析,画感兴趣区(ROI)测定间壁/侧壁比值(S/LR)。结果①15例左束支传导阻滞201TI和99mTc-MIBI的S/LR分别为0.65±0.09和0.46±0.10,明显低于对照组(0.89±0.08和0.88±0.09)(P<0.01)。②5例多谱勒超声心动描记术显示前间壁、前壁收缩运动减弱。③9例冠状动脉造影者2例正常,7例显示冠状动脉狭窄>50%。结论①15例左束支传导阻滞显示间壁201TI和99mTc-MIBI摄取的显著不匹配(99mTc-MIBI>201TI)。②冠状动脉造影提示有冠状动脉狭窄的表现。因此,左束支传导阻滞行核素心肌显像是明确有无冠心病的有效检测方法之一。     

Prognostic value of thallium-201 myocardial scintigraphy after atrial transoesophageal pacing in patients with suspected coronary artery disease

Fifty-five patients with suspected coronary artery disease underwentplanar thallium-201 myocardial scintigraphy after atrial transoesophagealpacing. Coronary angiography was carried out in all patients.Eighteen patients had no myocardial infarction, but a greaterthan 50% narrowing of at least one main vessel: initial hypoperfusionwith redistribution at 4 h occurred in 16 patients (sensitivity89%). Twenty-one patients had had a previous myocardial infarction:a reversible thallium defect was observed in 12 patients andan irreversible defect in the nine remaining patients. Sixteenpatients had normal coronary arteries: a reversible thalliumdefect was observed in three patients (specflcity 81%). Aftera mean follow-up of 22±13 months (range 6 to 40), 23cardiac events occurred: cardiac death in one patient, unstableangina in three, and revascularization procedures for recurrentangina despite medical therapy in 19 (coronary artery bypasssurgery in 7 and coronary angioplasty in 12). By univariateanalysis, the predictors of future cardiac events were a historyof previous myocardial infarction (odds ratio 55, P<0.02)multivessel coronary artery disease (odds ratio 9.6, P<0.0002),angina during atrial pacing (odds ratio 5.1, P<0.05), abnormalscintigraphy (odds ratio 17.1, P<0.001) and reversible perfusiondefect after pacing (odds ratio 7.9, P<0.002). By multivariateanalysis, multivessel disease (P<0.004) and reversible perfusiondefect after pacing (P<0.02) were the only independent predictorsof future cardiac events. In conclusion, thallium-201 myocardial scintigraphy after transoesophagealatrial pacing is accurate for the diagnosis and prognosis ofpatients with suspected coronary artery disease, and may beundertaken in patients unable to perform exercise stress testing.     

完全性左束支传导阻滞733例临床分析

目的探讨完全性左束支传导阻滞（CLBBB）合并冠心病患者的临床特点。方法回顾性分析2002年1月至2008年1月733例CLBBB住院患者资料,对比合并冠心病和不合并冠心病患者的临床特点,通过回归分析找出CLBBB患者中与冠心病相关的独立预测因素。结果733例左束支传导阻滞患者中合并高血压、冠心病和扩张型心肌病者分别占49.4%、44.1%和26.5%。合并心脏扩大或心功能不全者58%,合并其他心律失常者19.9%。多元回归分析结果：性别（P〈0.01,B=1.991,95%CI：1.375～2.882）、年龄≥65岁（P〈0.01,B=2.793,95%CI：1.948～4.005）、高血压（P=0.022,B=1.522,95%CI：1.062～1.640）、糖尿病（P〈0.001,B=2.459,95%CI：1.540～3.926）、高血脂（P=0.803,B=1.057,95%CI：0.682～2.180）与冠心病发生正相关,而扩张型心肌病（P〈0.001,B=0.072,95%CI：0.045～0.127）、心脏瓣膜病（P=0.027,B=0.253,95%CI：0.075～0.853）、房颤或房扑（P=0.024,B=0.564,95%CI：0.343～0.927）、其他传导阻滞（P〈0.001,B=0.418,95%CI：0.263～0.665）与冠心病发生呈负相关。结论CLBBB患者中年龄≥65岁、男性、高血压、糖尿病患者容易合并冠心病;而扩张型心肌病、房颤或房扑、合并其他类型传导阻滞、心脏扩大或心功能不全在未合并冠心病的CLBBB患者中更常见。     

Myocardial bridging of the left anterior descending artery: Evaluation using exercise thallium-201 myocardial scintigraphy

Seven patients with myocardial bridging of the left anterior descending coronary artery were evaluated by means of thallium-201 exercise scintigraphy. The degree of systolic narrowing was 60–70% in five patients and 75–80% in two patients. All patients had presented with chest pain. The resting electrocardiogram was normal in six patients; there were ST segment and T-wave abnormalities in one patient. No patient complained of chest pain during exercise. The exercise electrocardiogram was negative in six patients and inconclusive in one patient. Exercise myocardial scans were negative in all seven patients. We conclude that no evidence of ischemia was demonstrated in patients with myocardial bridging of the left anterior descending coronary artery as determined by exercise electrocardiography and stress thallium-201 scintigraphy.     

Long-term (10 years) prognostic value of a normal thallium-201 myocardial exercise scintigraphy in patients with coronary artery disease documented by angiography

In order to assess the prognostic significance of normal exercisethallium-210 myocardial scintigraphy in patients with documentedcoronary artery disease, we studied the incidence of cardiacdeath and non-fatal myocardial infarction in 69 symptomaticpatients without prior Q wave myocardial infarction, who demonstratedone or more significant coronary lesions (stenosis 70%) on anangiogram performed within 3 months of scintigraphy (Group 1).These patients were compared to a second group of 136 patientswith an abnormal exercise scintigram, defined by the presenceof reversible defect(s) and angiographically proven coronaryartery disease (Group 2), and to a third group of 102 patientswith normal exercise scintigraphy without significant coronarylesions (stenosis 30%) or with normal coronary angiography (Group3). In contrast to coronary lesions observed in Group 2, patientsin Group I presented more frequently with single- vessel disease(83% vs 35%, P>0·0001) and with more distal lesions(55% vs 23%, P>0·0001). Over a mean follow-up periodof 8·6 years, one fatal and eight non-fatal cases ofmyocardial infarction were observed in Group 1. The majorityof patients in Group 1 were treated medically: only 24 (35%)underwent myocardial revascularization, usually by coronaryangioplasty. There was no significant difference in the incidenceof combined major cardiac events (cardiac death, non-fatal myocardialinfarction) in patients with normal exercise scintigraphy, withor without documented coronary artery disease (Groups 1 and3), while the incidence was higher in Group 2. However, whilethe mortality remained very low in Group 1, the incidence ofnon-fatal myocardial infraction was not different from thatof Group 2, where most patients underwent revascularizationprocedures. In conclusion, patients with coronary artery disease and a normalexercise thallium-201 myocardial scintigram usually have mildcoronary lesions (single-vessel disease, distal location) andgood long-term prognosis, with a low incidence of cardiac death.     

Recovery of complete left bundle branch block following heart failure improvement by left bundle branch pacing in a patient

A 57‐year‐old male presented with symptomatic systolic heart failure and complete left bundle branch block (LBBB). Left bundle branch pacing corrected LBBB at a low capture threshold (0.5V @0.4ms) with right bundle branch conduction delay and paced QRS morphology changed to near‐normal by adjusting AV delay with diminished RBBD. At 1‐year follow‐up, the patient had a significant improvement in heart failure and LBBB automatically resolved with a rate‐dependent pattern. LBBP may be an alternative to conventional cardiac resynchronization therapy with the likelihood of recovery of LBBB. More research is needed to evaluate the potential use of this pacing strategy in patients with LBBB and heart failure.     

Left bundle branch block associated with propoxyphene hydrochloride poisoning

Described is the case of a patient who developed left bundle branch block following acute propoxyphene hydrochloride overdosage. The left bundle branch block was transient and associated with no permanent sequelae. Previously documented cardiac abnormalities, specific narcotic antagonist therapy, and animal studies correlating cardiac toxicity of propoxyphene hydrochloride with its potent local anesthetic action are discussed.     

右束支传导阻滞在急性心肌梗死中的临床意义

目的　评价伴随急性心肌梗死 (AMI)出现的右束支传导阻滞 (RBBB)的临床意义。方法　 2 94例 AMI分为RBBB组和非 RBBB组 ,比较两组患者的年龄、梗死部位、血清磷酸肌酸激酶 (CK)及其同工酶 (CK- MB)水平、心功能状态、严重并发症及住院死亡率。结果　 RBBB组血清 CK、CK- MB平均峰值为 (2 2 82 .0± 6 74.3) u/ L、(2 5 2 .6±137.3) u/ L ,明显高于非 RBBB组的 (192 0 .4± 5 6 9.2 ) u/ L、(114.8± 5 6 .7) u/ L (P<0 .0 0 5和 P<0 .0 1)。 RBBB组killip平均级别为 2 .33± 0 .5 4级 ,非 RBBB组为 1.46± 0 .6 3级 (P<0 .0 5 ) ,RBBB左心室舒张期末内径 (5 3.2± 9.6 m m )大于非 RBBB组 (4 5 .8± 8.2 m m,P<0 .0 5 ) ,左心室射血分数 [(4 8.9± 7.6 ) %]小于非 RBBB组 [(6 7.0± 3.7) %,P<0 .0 1]。 RBBB组心脏并发症发生率和住院死亡率高于非 RBBB组 (分别为 70 .8%和 39.0 %,P<0 .0 1;43.8%和 14.6 %,P<0 .0 1)。结论　 AMI并 RBBB患者梗死面积大 ,严重心脏并发症发生率和住院死亡率高。     

完全性左束支阻滞的发生率及心电图特点

目的 观察受检者完全性左束支阻滞的发生率及心电图特点.方法 记录和分析86621例常规12导联同步心电图,分别统计完全性左束支阻滞(CLBBB)及右束支阻滞(RBBB)的发生情况及心电图特点.结果 检出完全性左束支阻滞(CLBBB) 170例,占0.19％;检出RBBB3243例(男2252例,年龄4～98岁;女991...     

Remarkable response to cardiac resynchronization therapy via left bundle branch pacing in patients with true left bundle branch block

BackgroundLeft bundle branch pacing (LBBP) has been suggested as an alternative means to deliver cardiac resynchronization therapy (CRT).HypothesisLBBP may deliver resynchronization therapy along with an advantage over traditional biventricular (BiV) pacing in clinical outcomes.MethodsHeart failure patients who presented LBBB morphology according to Strauss''s criteria and received successful CRT procedure were enrolled in the present study. Propensity score matching was applied to match patients into LBBP‐CRT group and BiV‐CRT group. Then, the electrographic data, the echocardiographic data and New York heart association (NYHA) class were compared between the groups.ResultsTwenty‐one patients with successful LBBP procedure and another 21 matched patients with successful BiV‐CRT procedure were finally enrolled in the study. The QRS duration (QRSd) was narrowed from 167.7 ± 14.9 ms to 111.7 ± 12.3 ms (P < .0001) in the LBBP‐CRT group and from 163.6 ± 13.8 ms to 130.1 ± 14.0 ms (P < .0001) in the BiV‐CRT group. A trend toward better left ventricular ejection fraction (LVEF) was recorded in the LBBP‐CRT group (50.9 ± 10.7% vs 44.4 ± 13.3%, P = .12) compared to that in the BiV‐CRT group at the 6‐month follow‐up. A trend toward better echocardiographic response was documented in patients receiving LBBP‐CRT procedure (90.5% vs 80.9%, P = .43) and more super CRT response was documented in the LBBP‐CRT group (80.9% vs 57.1%, P = .09) compared to that in the BiV‐CRT group.ConclusionsLBBP‐CRT can dramatically improve the electrical synchrony in heart failure patients with LBBB. Meanwhile, compared with the traditional BiV‐CRT, it has a tendency to significantly improve LVEF and enhance the NYHA cardiac function scores.