112例左束支传导阻滞患者冠状动脉造影结果及临床特点分析

目的探讨左束支传导阻滞(LBBB)患者冠状动脉造影结果及临床特点。方法分析112例具有冠状动脉造影结果的LBBB患者的临床资料,冠状动脉至少1支主要分支管腔狭窄>50%为冠心病的诊断标准。结果 112例患者中,46例符合冠心病诊断标准(41.1%),其中24例为冠状动脉单支病变(52.2%),14例为冠状动脉2支病变(30.4%),8例为左主干病变或者3支病变(17.4%)。LVEF>40%的92例患者中,有左主干病变或者3支病变的仅为5例(5.4%);20例LVEF≤40%的患者中,则有3例(15.0%)为左主干病变或者3支病变。结论冠心病为LBBB的第1位病因,依次为高血压、糖尿病、扩张型心肌病及单纯LBBB;诊断为冠心病的LBBB患者中以冠状动脉单支病变为主,因此,冠心病的严重程度与LBBB没有直接关系。LBBB伴有左心室收缩功能不全的患者中左主干或者3支病变的发生率明显高于不伴有左心室收缩功能不全的患者。     

Left ventricular performance during exercise in patients with left bundle branch block: evaluation by gated radionuclide ventriculography

To investigate changes in left ventricular (LV) function during exercise in patients with left bundle branch block (LBBB), 22 patients without a history or physical findings of previous myocardial infarction or LV dysfunction were studied by gated radionuclide ventriculography (GRNV) at rest and during bicycle exercise. Coronary arteriography demonstrated greater than 75% diameter narrowing of at least one coronary artery in nine patients. Of the remaining 13 patients, GRNV demonstrated wall motion abnormalities in seven patients either at rest or with exercise. During exercise, mean ejection fraction (EF) did not increase in patients without coronary artery disease (CAD). Patients with CAD had a 12-point fall in mean EF with exercise. We conclude that LV reserve, as demonstrated by ability to increase EF with exercise, is impaired in patients with LBBB even in the absence of CAD or other underlying cardiac disease and that standard GRNV criteria to exclude the presence of CAD (a greater than five-point increase in EF with exercise and normal wall motion) are not strictly applicable in screening patients with LBBB.     

Cardiomyocyte apoptosis in cocaine-induced myocarditis with involvement of bundle of His and left bundle branch

Non-invasive diagnosis of coronary artery disease (CAD) in patients with left ventricular (LV) dysfunction and left bundle branch block (LBBB) remains challenging, and there is no consensus on the role of myocardial sesta-MIBI perfusion scintigraphy with pharmacological stress (dip-MIBI) or dipiridamole echocardiography (dip-ECHO). We thus performed a prospective study to test the diagnostic accuracy of such non-invasive tests. 27 consecutive patients with both LV dysfunction and LBBB undergoing diagnostic work-up for CAD were studied simultaneously with dip-ECHO and dip-MIBI. The sensitivity for CAD for dip-ECHO and dip-MIBI was respectively 42% and 67%, with specificity 93% and 53%, and likelihood ratio (LR)-positive 6.3 and LR-negative 0.6 for both. Given the low accuracy of both dip-ECHO and dip-MIBI in detecting CAD in patients with concomitant LV dysfunction and LBBB, coronary angiography should be performed as the default diagnostic strategy in such patients.     

踝臂指数与老老年患者冠状动脉狭窄程度的相关性研究

目的探讨老老年冠心病患者踝臂指数(ABI)与冠状动脉狭窄严重程度的相关性,评价ABI对冠状动脉狭窄严重程度的预测价值。方法连续入选78例冠状动脉造影的老老年患者(年龄≥80岁)进行研究,根据冠状动脉造影结果分为无病变者(8例)、单支病变患者(10例)、2支病变患者(14例)、3支或左主干病变患者(46例)。对所有患者进行ABI测量、病史采集及血液生化检测。结果 ABI与Gensini评分呈负相关;冠状动脉3支或左主干病变患者ABI显著降低,差异有统计学意义(P0.001),而无病变、单支病变、2支病变患者ABI差异无统计学意义;ABI对3支或左主干病变预测价值的ROC曲线下面积为(0.79±0.04,95% CI:0.69～0.85,P0.001);ABI≤0.9作为截断值预测3支或左主干病变具有较高的特异性(89.5%)和敏感性(53.6%)。结论老老年冠心病患者ABI与冠状动脉狭窄严重程度呈负相关,ARI≤0.9对预测冠状动脉3支和左主干病变具有较高的特异性和敏感性。     

Influence of underlying coronary artery disease on the natural history and prognosis of exercise-induced left bundle branch block

The long-term prognosis of exercise-induced left bundle branch block (BBB) in patients with and without underlying coronary artery disease (CAD) was examined by following 15 patients (7 with normal coronary arteries and 8 with CAD) for an average of 6.6 years (range 2.2 to 11.2). Over the follow-up interval, permanent left BBB developed in 8 of the 15 patients. Seven of these 8 had underlying CAD, compared to 0 of 6 patients with normal coronary arteries and normal left ventricular function (p less than 0.002). In 1 patient with normal coronary arteries and a left ventricular ejection fraction of 0.34, permanent left BBB developed. During follow-up, 4 patients died; 3 had significant CAD and 1 had depressed left ventricular function. In no patient did high-grade atrioventricular block develop and no patient required pacing. Thus, development of permanent left BBB in patients with exercise-induced left BBB is related to presence or absence of underlying CAD or myocardial disease. When left BBB is found in the absence of underlying heart disease, there does not tend to be progression of the conduction disturbance and the prognosis is excellent.     

Prognostic and predictive value of exertional hypotension in suspected coronary heart disease

The prognostic and predictive value of exertional hypotension was assessed in 1,241 patients having treadmill maximal exercise testing, coronary arteriography, and follow-up averaging 5.4 years. Medically treated patients with coronary artery disease (CAD) with exertional hypotension had poorer survival than did those without such hypotension; however, maximum systolic pressure during exercise was a more powerful predictor of survival. Patients with exertional hypotension had more extensive CAD and more left ventricular (LV) dysfunction than did patients who had an increase in blood pressure with exertion; these findings probably account for the impaired survival. However, exertional hypotension, was an insensitive indicator of significant left main coronary artery stenosis, 3-vessel disease, or severe resting LV dysfunction.     

Relationship between the degree of coronary artery disease and of left ventricular function and the duration of the QT-interval in ECG

Advanced coronary artery disease (CAD), impaired left ventricular function and prolongation of the QT-interval are considered risk factors for sudden cardiac death in CAD-patients. So far, however, there are no studies investigating in detail whether there is a correlation between the QT-interval and changes in coronary anatomy or changes in left ventricular function. Therefore, coronary angiographic data were related to QT-intervals in 304 patients, who were catheterized because of suspected coronary artery disease. QT-intervals were expressed as QTc = QT/square root RR (Bazett's correction for heart rate), left ventricular function was assessed by the ejection fraction of the ventricular angiogram, and coronary angiograms were classified according to the Gensini score as well as into 1-, 2- and 3-vessel disease (stenoses greater than or equal to 50%). A multidimensional linear regression model was employed to eliminate the effects of varying mean rates still present after application of Bazett's formula. In patients with 1-, 2- and 3-vessel disease, significant changes of QTc were observed only in patients with impaired left ventricular function (EF less than 60%). In these patients the QTc-interval increased significantly from 1- to 3-vessel disease. If the critical degree of coronary stenosis was changed from greater than or equal to 50% to greater than or equal to 90% further prolongations of QTc were noted. In patients with 1-, 2- and 3-vessel disease the QTc-duration difference was further enhanced if either the proximal part of the descending branch of the left coronary artery (LAD) or the left main stem were affected (stenoses greater than or equal to 50%). The data reveal that prolongation in the duration of electrical systole correlates with known cardiac risk factors for sudden death, i.e. 3-vessel-disease, proximal LAD or left main stem stenosis and impaired left ventricular function. In the individual patient, however, the prognostic value of a single QTc-determination is limited because of a large interindividual variation of the data.     

Usefulness of the Agatston score = 0 to exclude ischemic cardiomyopathy in patients with heart failure

Quantification of coronary artery calcium has prognostic value and is commonly used in asymptomatic patients. Routine clinical use of coronary artery calcium in other populations remains uncertain. We sought to understand the potential application of the Agatston score in patients with heart failure (HF). For this purpose, 3 populations were identified: (1) patients with an Agatston score equal to 0, (2) patients with high-risk coronary artery disease (CAD) defined as 3-vessel, left main, or 2-vessel disease involving the proximal left anterior descending coronary artery, and (3) patients with HF symptoms and left ventricular (LV) ejection fraction <50%. Excluding patients with HF or LV dysfunction, 738 patients (mean age 52 ± 10 years, 43% men) had an Agatston score equal to 0. Of these, 18 (2%) had obstructive CAD (diameter stenosis ≥50%), 8 (1%) had diameter stenoses ≥70%, and none had high-risk CAD. The 74 patients with high-risk CAD without LV dysfunction had high Agatston scores (mean 895 ± 734, median 716, range 50 to 3,210). In total 153 patients with a history of HF and abnormal ejection fraction were identified. All 13 patients with ischemic cardiomyopathy had Agatston scores >0, whereas 46 of 140 patients (30.1%) with nonischemic causes had an Agatston score equal to 0. An Agatston score equal to 0 identified nonischemic causes with a specificity of 100% (confidence interval 90 to 100) and positive predictive value of 100% (confidence interval 90 to 100). Agatston score equal to 0 had incremental value to pretest probability for CAD. In conclusion, an Agatston score equal to 0 confers a very low likelihood of obstructive CAD, appears to rule out high-risk CAD, and thus may be used to rule out ischemic cardiomyopathy in patients with HF.     

Correlation of the exercise ST/HR slope with anatomic and radionuclide cineangiographic findings in stable angina pectoris

A rate-related change in ST-segment depression with exercise (ST/HR slope) of 6.0 microV/beat/min or more has been proposed as an accurate predictor of 3-vessel coronary artery disease (CAD). To further assess the accuracy and functional correlates of this method, exercise electrocardiograms were compared with radionuclide rest and exercise left ventricular (LV) ejection fraction (EF) and angiography in 35 patients with stable angina. The ST/HR slope was significantly increased in patients with 3-vessel CAD. An ST/HR slope of 6.0 or more identified 3-vessel CAD with a sensitivity of 89% and specificity of 88%. The predictive value for 3-vessel CAD was 73% owing to the presence of 3 false-positive slopes. The patients from whom these slopes were derived had functionally severe 2-vessel CAD, with an average decrease in exercise LVEF of 13%. Two of these 3 had additional left main CAD and the third has unsuspected additional aortic regurgitation. For the entire group, the exercise ST/HR slope was linearly related to the exercise change in LVEF (r = -0.55, p less than 0.001). Mean exercise change in LVEF for stable angina patients with ST/HR slopes of 4.5 or more was significantly different from that for patients with lower ST/HR slopes (-12 +/- 1% vs + 2 +/- 2%, p less than 0.0001). Thus, the ST/HR slope is both sensitive and specific for the identification of 3-vessel CAD, and high ST/HR slopes in patients with less extensive anatomic disease may predict functionally severe ischemia.     

Diagnostic value of exercise tomoscintigraphy with thallium 201 in patients with complete left branch block

Eighteen patients with rate-dependent (n = 5) or chronic (n = 13) left bundle branch block underwent thallium 201 exercise SPECT and selective coronary arteriography. 15 patients showed significant septal or anteroseptal perfusion defects on the exercise scintigrams, but in only 4 of them did the coronary disease involve the left anterior descending artery (LAD) (n = 3) or the left main coronary artery (n = 1). Among patients with normal scintigrams, one had right coronary artery stenosis. Test performance in detecting individual coronary artery stenosis greater than 70 p. 100 was: sensitivity 80 p. 100 (4/5) and specificity 15 p. 100. In patients with left bundle branch block, T1 201 SPECT was indeterminate for LAD disease due to reversible septal perfusion defect. We conclude that the usefulness of stress thallium 201 SPECT in patients with left bundle branch block is very limited.     

Risk stratification of single or double vessel coronary artery disease and impaired left ventricular function using exercise radionuclide angiography

Patients with 3-vessel coronary artery disease (CAD) and normal left ventricular (LV) function have a worse prognosis if they manifest ischemia during exercise testing. The present study determines if exercise radionuclide angiography can aid in the risk stratification of patients with 1- or 2-vessel CAD and impaired LV function (ejection fraction less than 50%). Sixty-five consecutive patients with these findings were followed for a median duration of 24 months (range 12 to 49). Eleven of the 65 patients (17%) had severely ischemic exercise radionuclide angiograms, defined as: a decrease in ejection fraction with exercise; greater than or equal to 1.0 mm of ST-segment depression; and peak exercise workload less than or equal to 600 kg-m/min. During follow-up 11 patients had initial significant cardiac events: 4 cardiac deaths, 1 cardiac arrest, 4 myocardial infarctions and 2 bypass or angioplasty procedures for unstable angina greater than or equal to 3 months after the exercise study. Four of 11 patients (36%) with severely ischemic exercise radionuclide angiograms had events, compared to 7 of 54 patients (13%) without ischemic radionuclide angiograms. Event-free survival at 18 months was 73% for patients with severe exercise ischemia versus 92% for those without ischemia (p less than 0.05). Univariate analysis showed that severe ischemia on radionuclide angiography was the only variable of several tested that significantly predicted future cardiac events (chi-square = 8.16, p less than 0.005). Among patients with 1- or 2-vessel CAD and impaired resting LV function, severe ischemia on exercise radionuclide angiography identifies a subgroup at high risk for future cardiac events.     

Value of exercise testing in determining the risk classification and the response to coronary artery bypass grafting in three-vessel coronary artery disease: a report from the Coronary Artery Surgery Study (CASS) registry

To determine whether exercise testing can identify higher risk patients with 3-vessel coronary artery disease (CAD) whose survival might be prolonged by coronary artery bypass grafting (CABG), the results of CABG were compared with those of medical therapy in 1,249 nonrandomized patients with 3-vessel CAD from the Coronary Artery Surgery Study (CASS) registry who underwent exercise testing. Analysis of 28 variables by Cox's regression model for survival revealed an independent effect of the left ventricular (LV) score, the final exercise stage, and treatment received on survival. Seven-year survival rates between medical and surgical therapy were compared among subsets of patients according to the LV function and the results of exercise testing. Among patients with normal LV function, those with at least 1 mm of ischemic ST-segment depression or low exercise capacity had better 7-year survival if treated by surgical rather than medical therapy (p less than 0.05). Survival was not different between the medical and surgical groups in patients without ischemic ST depression or with good exercise capacity. Among patients with impaired LV function, surgery improved survival in most subsets of patients with the exception of patients with a preserved exercise capacity. These results support the use of exercise testing in the risk stratification of patients with 3-vessel CAD.     

"Left main equivalent" coronary artery disease: its clinical presentation and prognostic significance with nonsurgical therapy

The clinical characteristics and nonsurgical prognosis of 55 patients with "left main (LM) equivalent" coronary artery disease (CAD) were evaluated and defined as: (1) greater than or equal to 75% diameter reduction of the left anterior descending coronary artery (LAD) before the takeoff of any large septal perforator or anterolateral (diagonal) branches; (2) greater than or equal to 75% diameter reduction of the left circumflex artery (LC) before the takeoff of any large marginal branch; and (3) absence of greater than or equal to 50% stenosis of the LM coronary artery. Compared with nonsurgically treated patients with greater than or equal to 75% stenosis of the LM artery, patients with LM equivalent CAD had a shorter duration of symptoms (median of 51 months vs 66 months) and more often had a Q wave on the electrocardiogram (60 vs 39%). Survival in patients with LM equivalent CAD (78% at 1 year and 55% at 5 years) was better than that in patients with LM disease with nonsurgical therapy (65% at 1 year and 40% at 5 years) (p = 0.02), although the rate of freedom from cardiovascular events was not significantly different. Compared with other nonsurgically treated patients with 2- or 3-vessel CAD involving the LAD and LC (28 and 42%, respectively, with progressive angina), patients with LM equivalent CAD had more severe anginal symptoms (55% with progressive angina) and a longer duration of symptoms (medians of 20 months in 2-vessel CAD, 36 months in 3-vessel CAD and 51 months in LM equivalent CAD).(ABSTRACT TRUNCATED AT 250 WORDS)     

Cardiokymography during exercise testing: A new device for the detection of coronary artery disease and left ventricular wall motion abnormalities

The cardiokymograph (CKG) is a device that has been shown to reflect left ventricular (LV) wall motion abnormalities. Its accuracy in detecting coronary artery disease (CAD) during treadmill exercise testing was assessed in 204 consecutive patients undergoing coronary arteriography. Of the 188 patients with a technically adequate CKG, 146 (78%) had significant CAD. The sensitivity and specificity were similar for both the exercise electrocardiogram (ECG) (66% and 86%, respectively) and the exercise CKG (73% and 95%, respectively). An abnormal exercise CKG was significantly more common In patients with 3-vessel CAD than in those with 1-vessel disease (97% versus 52%, respectively;p < 0.001) and in patients with left anterior descending disease than in those without (85% versus 26%, respectively; p < 0.001). Seventy patients showed both an abnormal exercise ECG and CKG; all had CAD and 86% had multivessel CAD. Forty-eight patients demonstrated a normal exercise ECG and CKG; 29% had CAD but only 6% had multivessel CAD. Among 55 patients who had simultaneous exercise radionuclide ventriculography, new septal or apical wall motion abnormalities were found in 79% (23 of 29) of patients with an abnormal CKG compared with 19% (5 of 26) of patients with a normal CKG (p < 0.001). Thus, the CKG during exercise testing accurately reflects LV wall motion abnormalities and can be used to improve the diagnostic accuracy of exercise testing as an additional marker of myocardial ischemia.     

Prognostic implications of symptomatic versus asymptomatic (silent) myocardial ischemia induced by exercise in mildly symptomatic and in asymptomatic patients with angiographically documented coronary artery disease

Patients with coronary artery disease (CAD) may undergo periods of reversible myocardial ischemia without experiencing angina. To study the prognostic implications of "silent" myocardial ischemia induced by exercise, exercise electrocardiography and radionuclide angiography were performed in 131 consecutive patients with CAD, preserved left ventricular (LV) function at rest and mild or no symptoms during medical therapy. All patients who died during medical therapy were in the subgroup of patients with 3-vessel CAD in whom exercise-induced ischemia developed, which was characterized by both a decrease in LV ejection fraction and ST-segment depression. Patients in whom angina pectoris developed during exercise (54% of all patients) had a greater prevalence of this combined ischemic response to exercise than patients without angina (61% vs 27%, p less than 0.001) and also a greater prevalence of left main or 3-vessel CAD (59% vs 25%, p less than 0.001). However, when inducible ischemia was demonstrated, risk stratification and prognosis were the same whether the ischemic episode was symptomatic or silent. Among patients having both a reduction in ejection fraction and a positive ST-segment response, the likelihood of significant left main narrowing (13% vs 26%), 3-vessel CAD (56% vs 51%) and death during subsequent medical therapy (16% vs 9%) was similar in patients with silent compared to those with symptomatic ischemia. These data indicate that patients in whom angina develops during exercise have a greater prevalence of high-risk coronary anatomy and of inducible ischemia than patients without angina. However, once inducible ischemia is documented, the symptomatic response to exercise appears irrelevant for prognostic or risk stratification considerations.     

Bundle branch block in patients with chronic coronary artery disease: angiographic correlates and prognostic significance

The onset of bundle branch block during acute myocardial infarction is indicative of ischemia in the distribution of the left anterior descending coronary artery. However, whether patients with chronic coronary artery disease and bundle branch block have a predominance of left anterior descending artery lesions is not known. Similarly, the prognostic implications of bundle branch block have been studied primarily in the setting of acute myocardial infarction, and the independent prognostic implications of bundle branch block in patients with chronic coronary artery disease are not known. The electrocardiograms (ECGs) of 15,609 patients with chronic coronary artery disease who underwent coronary and left ventricular angiography as part of the Coronary Artery Surgery Study (CASS) were reviewed, and 522 patients with bundle branch block were identified. Patients with bundle branch block had both more extensive coronary artery disease and worse left ventricular function than did patients without bundle branch block. However, no particular location of coronary artery stenosis or left ventricular wall motion abnormality predominated in patients with bundle branch block. During a follow-up period of 4.9 +/- 1.3 years, 2,386 patients died. Actuarial probability of mortality at 2 years in patients with left bundle branch block was more than five times that in patients without bundle branch block (p less than 0.0001), and in patients with right bundle branch block the mortality rate was approximately twice that in patients without bundle branch block (p less than 0.0001). Stepwise Cox regression analysis showed that left bundle branch block, but not right bundle branch block, was a strong predictor of mortality, independent of degree of heart failure, extent of coronary disease and other variables (p less than 0.0001).(ABSTRACT TRUNCATED AT 250 WORDS)     

Risk of developing an acute myocardial infarction or sudden coronary death in patients with exercise-induced silent myocardial ischemia. A report from the Coronary Artery Surgery Study (CASS) registry

To evaluate whether patients with silent myocardial ischemia during exercise testing are at increased risk for developing a subsequent acute myocardial infarction or sudden death, the data on 424 such patients with proven coronary artery disease (CAD) from the Coronary Artery Surgery Study (CASS) registry were analyzed. These patients (group 1) were compared with 456 other patients with CAD (group 2) who had both ischemic ST depression and angina pectoris during exercise testing and with 1,019 control patients without CAD. The probability of remaining free of a subsequent acute myocardial infarction or sudden death at 7 years was 80 and 91%, respectively, for group 1, 82 and 93%, respectively, for group 2 (difference not significant, compared with group 1), and 98 and 99%, respectively, for the control patients (p less than 0.001), compared with group 1 or 2). Among patients in group 1, the probability of remaining free of myocardial infarction and sudden death at 7 years was related to the severity of CAD and presence of left ventricular (LV) dysfunction, and ranged from 90% for patients with 1-vessel CAD and preserved LV function to 38% for patients with 3-vessel CAD and abnormal LV function (p less than 0.001). Thus, patients with either silent or symptomatic ischemia during exercise testing have a similar risk of developing an acute myocardial infarction or sudden death--except in the 3-vessel CAD subgroup, where the risk is greater in silent ischemia. The risk of patients with silent myocardial ischemia is based primarily on angiographic variables.     

Comparison of presence and extent of coronary narrowing in patients with left bundle branch block without diabetes mellitus to patients with and without left bundle branch block but with diabetes mellitus

We prospectively analyzed the clinical, echocardiographic, and coronary arteriographic data of 51 patients with type 2 diabetes mellitus with left bundle branch block (LBBB), 51 patients with type 2 diabetes mellitus without LBBB, and 51 patients with isolated LBBB matched for age and gender. Extent of coronary artery disease (CAD) was classified according to the standard method into 1-, 2-, or 3-vessel disease and was estimated by calculation of the Gensini score. The left ventricular ejection fraction was analyzed by echocardiography. Age, gender, and percentage of patients with a smoking habit or family history of CAD did not differ among the groups. The rates of hypertension and levels of serum creatinine, cholesterol, and triglycerides were statistically higher in group I compared with the other 2 groups. Patients with diabetes and LBBB (group I) had significantly higher scores for the severity (Gensini score) of CAD (p <0.001) and more 3-vessel disease (p <0.001). After adjustment for hypertension, hypertriglyceridemia, and hypercholesterolemia with covariance analysis, the presence of LBBB was also associated with a higher Gensini score in patients with diabetes compared with those with diabetes but without LBBB and those with isolated LBBB (p <0.001). The present study, for the first time, has shown that patients with type 2 diabetes mellitus and concomitant LBBB have more severe and extensive CAD and advanced left ventricular dysfunction compared with those with diabetes but without LBBB and those with isolated LBBB.     

Influence of the angiocardiographic severity of ischemic heart disease on QTc duration

The influence of severity of coronary artery disease (CAD) on the duration of corrected electrical systole (QTc) and the prognostic value to predict sudden death of this index were retrospectively evaluated in 123 non-consecutive patients with history of stable angina who underwent cardiac catheterization. Fifteen patients had no angiographic evidence of CAD (O-V group). The 108 patients with a greater than or equal to 70% luminal diameter narrowing of a major coronary artery were further subdivided: 23 patients had 1-vessel (1-V group), 40 patients had 2-vessel (2-V group) and 45 had 3-vessel (3-V group) coronary artery disease; 26 patients showed normal left ventricular (LV) wall motion (A group), 57 patients showed asynergic contraction of 1 or 2 LV areas (B group) and 25 patients showed 3 or more areas of asynergy and/or aneurysm. Sixty-one patients had a previous myocardial infarction (MI). QT interval, calculated in the lead where it was longer, on 12-lead resting electrocardiograms recorded at a paper speed of 25 mm/sec, was corrected by the formula: QTc = QT/square root R-R. The follow-up was performed by telephone. At the time of angiography there was no significant difference in QTc duration between the different groups according to the severity of CAD (O-V, 1-V, 2-V and 3-V groups). Patients showing three or more areas of abnormal segmental wall motion and/or aneurysm (C group) had a significantly longer QTc (p less than 0.05) than patients with normal LV wall motion (A group).(ABSTRACT TRUNCATED AT 250 WORDS)     

Histopathologic correlates of left posterior fascicular block.

Thirteen hearts from subjects (10 male, 3 female; mean age 65 years) with left posterior fascicular block were studied. Left posterior fascicular block was associated with right bundle branch block in nine cases and alternated with left anterior fascicular block in three. In nine of the patients, the conduction disorders were observed during an episode of acute myocardial infarction. Of these nine patients, four showed interruptive lesions at the level of the posterior radiation of the left bundle or of the posterior portion of the main left bundle branch. Two were found to have severe alterations scattered throughout the left bundle branch system: One of them had alternating left anterior and left posterior fascicular block; and the other manifested complete heart block in the course of her illness. No interruptive changes of the posterior fibers were found in three cases in which the heart was obtained early after death. All 9 patients had severe coronary artery disease (six had triple vessel disease and three of the six had a left main coronary arterial stenosis or obstruction; two patients had double vessel disease). Among the four patients with chronic left posterior block, three were found to have heavy calcifications of the left side of the cardiac skeleton; the remaining one had diphtheritic myocarditis. All had major alterations of the left-sided conduction system that were consistently maximal at the level of the posterior fibers or posterior portion of the main left bundle branch. In two of these patients scattered lesions were found throughout the left bundle branch fibers; one had alternating left anterior and left posterior fascicular block and the other had complete heart block. In general, the alterations underlying left posterior fascicular block were less widely spread than in left anterior fascicular block; however, they were more severe and more proximally located.