QT interval dispersion: non-invasive marker of ischemic injury in patients with unstable angina pectoris?

Prognostic assessment of unstable angina pectoris is a common clinical problem for physicians. Markers of myocardial cell injury, serial electrocardiographic findings and ST segment monitoring are mainly studied for prognosis. We investigated the relation between myocardial injury and the value of cardiac troponin T and QT interval dispersion in hospitalized unstable angina patients. This is a prospective study that includes adult patients admitted to an emergency department with Braunwald class IIIB unstable angina pectoris. Eighty-six patients were enrolled in the study (mean age of 57 +/- 12 years, 63 males and 23 females). Cardiac troponin T was assayed and QT dispersion calculated from surface ECG. Fifty-eight patients with troponin T < 0.1 ng/ml and 28 patients with troponin T levels > or = 0.1 formed group 1 and group 2, respectively. There were no significant differences in sex, age, history of coronary revascularization or ECG findings such as ST depression and T inversions between the two groups. The QT dispersion was significantly greater in patients with elevated cardiac troponin T levels (77 +/- 18 msec vs 38 +/- 13 mse; p < 0.014). Because QT interval dispersion exhibited an association with cardiac troponin T levels, it may be used as a non-invasive marker of ischemic injury in patients with unstable angina.     

QR in V1--an ECG sign associated with right ventricular strain and adverse clinical outcome in pulmonary embolism.

AIMS: To test the hypothesis that Qr in V(1)is a predictor of pulmonary embolism, right ventricular strain, and adverse clinical outcome. METHODS AND RESULTS: ECG's from 151 patients with suspected pulmonary embolism were blindly interpreted by two observers. Echocardiography, troponin I, and pro-brain natriuretic peptide levels were obtained in 75 patients with pulmonary embolism. Qr in V(1)(14 vs 0 in controls; p<0.0001) and ST elevation in V(1)> or =1 mV (15 vs 1 in controls; p=0.0002) were more frequently present in patients with pulmonary embolism. Sensitivity and specificity of Qr in V(1)and T wave inversion in V(2)for predicting right ventricular dysfunction were 31/97% and 45/94%, respectively. Three of five patients who died in-hospital and 11 of 20 patients with a complicated course, presented with Qr in V(1). After adjustment for right ventricular strain including ECG, echocardiography, pro-brain natriuretic peptide and troponin I levels, Qr in V(1)(OR 8.7, 95%CI 1.4-56.7; p=0.02) remained an independent predictor of adverse outcome. CONCLUSIONS: Among the ECG signs seen in patients with acute pulmonary embolism, Qr in V(1)is closely related to the presence of right ventricular dysfunction, and is an independent predictor of adverse clinical outcome.     

Right ventricle injury during acute pulmonary embolism leads to its remodeling

Right ventricular (RV) overload and hypoxia in acute pulmonary embolism (APE) may lead to RV myocardium injury reflected by elevated cardiac troponin levels. We studied 26 patients aged 57.2+/-17.8 years with first episode of APE. On admission troponin T (TnT) was measured. Transthoracic echocardiography was performed after 6 months of anticoagulation. Myocardial injury (TnT > or =0.03 ng/ml) was observed in 8 (30.8%) patients at the diagnosis. At follow up RV diastolic area tended to be larger in group with myocardial injury (25.0 (20.8-38.6) vs 18.4 (17.7-23.3) cm(2), p=0.06). Tricuspid annulus systolic velocity at tissue Doppler was lower in group with myocardial injury (0.12 (0.11-0.13) vs 0.15 (0.13-0.21) m/s, p=0.04), while no such a relationship was found for mitral annulus systolic velocity. TnT concentration correlated with RV diastolic area (r=0.61) and tricuspid annulus systolic velocity (r=-0.58) although not significantly (p=0.08 and p=0.09. respectively). Our data suggest that RV injury in acute phase of PE may lead to its remodeling.     

冠状动脉旁路移植术后ST-T改变的临床意义及评价

目的:探讨冠状动脉旁路移植术(CABG)后ST-T改变的临床意义. 方法:对2001年12月～2002年7月500例CABG患者术后进行心电图检测,每天1次,连续3天.如果有心电图改变,则每天两次,连续3天,并记录出院时的心电图.术后4～6小时,术后第1天上午7点,检查心肌酶谱和肌钙蛋白T(cTnT),如果有不正常,则连续检查3天,每天1次.结果:在500例患者中心电图出现ST-T改变有37例,同时cTnT阳性有10例.ST段抬高合并QRS波群改变5例中4例有cTnT阳性,ST段抬高合并高尖T波8例,2例cTnT阳性.右束支阻滞2例,都有cTnT阳性改变,ST段下移1例,广泛ST段抬高1例.肌酸激酶MB同工酶高于正常3倍只有5例,其中ST段抬高合并QRS波群改变3例,ST段下移1例,右束支阻滞1例.异常T波8例,单纯ST段抬高都不合并cTnT改变.ST段抬高合并QRS波群改变5例中3例进行了再次手术并应用了主动脉球囊反搏(IABP),这3例出院时心电图表现为陈旧性心肌梗死.广泛ST段抬高2例证实有急性心包积液,在出院时,ST段恢复到基线.结论:CABG后ST-T改变需综合分析,心电图的动态表现和心肌坏死的血清心肌标记物浓度的动态变化可诊断围手术期心肌梗死.     

肌钙蛋白T与N端B型尿钠肽前体对急性肺栓塞患者危险分层的意义

目的探讨联合检测生化标记物肌钙蛋白T（cTnT）和N端B型尿钠肽前体（NT—proBNP）水平对急性肺栓塞（APE）患者进行危险分层及预后判断的临床意义。方法根据血浆cTnT和NT—proBNP水平将59例APE患者分为3组：1组（14例）,cTnT〈0．1ng／ml,NT—proBNP〈100pg／ml;2组（28例）,cTnT≥0．1ng／ml或NT—proBNP≥100pg／ml;3组（17例）,cTnT≥0．1ng／ml且NT-proBNP≥100pg／ml,分析cTnT和（或）NT—proBNP升高对APE患者危险分层与临床预后的关系。结果三组间动脉血PaO2、P（A—a）O2比较差异有统计学意义（P〈0．01）。进行两两比较,1、3组动脉血PaO2、P（A—a）O2分别与其他各组相比差异有统计学意义（P〈0．01）。1组、2组、3组预后不良者分别为0（0％）、7例（25．0％）、9例（52．9％）,差异有统计学意义（P〈0．01）。59例APE患者中临床不良事件发生组与无临床不良事件组比较,PaO2、cTnT、NT—proBNP水平差异均有统计学意义（P〈0．01）。结论联合检测cTnT和NT—proBNP在APE患者早期危险分层、指导临床决策及预后判断中具有重要价值。     

Troponin T and quantitative ST-segment depression offer complementary prognostic information in the risk stratification of acute coronary syndrome patients

OBJECTIVES: Our primary objective was to examine the prognostic relationship between baseline quantitative ST-segment depression (ST) and cardiac troponin T (cTnT) elevation. The secondary objectives were to: 1) examine whether ST provided additional insight into therapeutic efficacy of glycoprotein IIb/IIIa therapy similar to that demonstrated by cTnT; and 2) explore whether the time to evaluation impacted on each marker's relative prognostic utility. BACKGROUND: The relationship between the baseline electrocardiogram (ECG) and cTnT measurements in risk-stratifying patients presenting with acute coronary syndromes (ACS) has not been evaluated comprehensively. METHODS: The study population consisted of 959 patients enrolled in the cTnT substudy of the Platelet IIb/IIIa Antagonism for the Reduction of Acute coronary syndrome events in a Global Organization Network (PARAGON)-B trial. Patients were classified as having no ST (n = 387), 1 mm ST (n = 433), and ST > or =2 mm (n = 139). Forty-percent (n = 381) were classified as cTnT-positive based on a definition of > or =0.1 ng/ml. RESULTS: Six-month death/(re)myocardial infarction rates were 8.4% among cTnT-negative patients with no ST and 26.8% among cTnT-positive patients with ST > or =2 mm. On ECGs done after 6 h of symptom onset, ST > or =2 mm was associated with higher risk compared to its presence on ECGs done earlier (odds ratio [OR] 7.3 vs. 2.1). In contrast, the presence of elevated cTnT within 6 h of symptom was associated with a higher risk of adverse events compared with elevations after 6 h (OR 2.4 vs. 1.5). CONCLUSIONS: Quantitative ST and cTnT status are complementary in assessing risk among ACS patients and both should be employed to determine prognosis and assist in medical decision making.     

急性ST段抬高型心肌梗死直接PCI术后ST段回落的临床研究

目的：通过观察急性ST段抬高型心肌梗塞（STEMI）直接经皮冠状动脉介入治疗（PCI）术后,梗塞相关动脉（IRA）达心肌梗塞溶栓（TIMI）血流3级患者心电图ST段回落程度,探讨ST段回落与心肌损伤及心脏收缩功能的关系。方法：选择在发病12h内接受直接PCI治疗后TIMI血流达到3级的STEMI患者115例,PCI术前、术后行心电图检查,观察ST段回落情况,术前、后测定患者肌酸激酶（CK）、肌酸激酶同工酶（CK-MB）及肌钙蛋白T（cTnT）,术后测定左室射血分数（LVEF）;按照ST段回落幅度（∑STR）不同,患者被分为两组：A组：∑STR〈50%,21例,为心肌灌注不良组,B组：∑STD≥50%,94例,为心肌灌注良好组;分析两组患者ST段回落程度与CK、CK-MB、cTnT及LVEF的关系。结果：（1）两组患者IRA部位、病变血管支数,PCI治疗前TIMI血流分级、cTnT水平,发病到PCI时间等差异均无显著性（P〉0.05）;（2）两组患者术前、后CK、CK-MB水平差异无显著性（P〉0.05）;（3）术后A组cTnT水平明显高于B组[（1.30±0.43）μg/L∶（1.0±0.45）μg/L,P〈0.05];（4）术后A组LVEF明显低于B组[（44.13±4.83）%∶（47.93±5.23）%,P〈0.05]。结论：急性ST段抬高型心肌梗塞直接PCI术后,TIMI血流达到3级,ST段回落良好的患者,心肌组织水平灌注程度较好,心肌损伤程度轻,左心收缩功能较好。     

Unstable angina: ST segment depression with positive versus negative T wave deflections--clinical course, ECG evolution, and angiographic correlation

Thirty-two consecutive patients who initially had horizontal or downward-sloping ST segment depression confined to the precordial leads were studied. Patients were divided into two groups: group A included 21 patients with horizontal or downward-sloping ST depression with peaked positive T waves, and group B comprised 11 patients with peaked negative T waves and downward or horizontal ST depression. The incidence of acute myocardial infarction (AMI) was similar (group A 38.1% vs group B 36.4%; p greater than 0.05). In-hospital mortality was much more significant in group B (p = 0.03). Coronary arteriography was performed in 31 patients. Of the 10 patients in group B who were catheterized, seven (70%) had left main occlusion. Of the 21 patients in group A, none had a significant left main lesion (p = 0.001), although eight (38.1%) had single-vessel disease (p = 0.05). Thus the ECG pattern of horizontal or downward-sloping ST depression passing into a peaked negative T wave identifies a subgroup of high-risk patients in whom the prognosis is poor once AMI occurs. Early catheterization is recommended when this ischemic pattern is apparent on the ECG.     

ST segment shifts are poor predictors of subsequent Q wave evolution in acute myocardial infarction. A natural history study of early non-Q wave infarction

Acute ST segment elevation is regarded generally as the sine qua non of evolving Q wave myocardial infarction (MI) because such electrocardiographic (ECG) injury is believed to be a marker of transmural ischemia and a forerunner of transmural necrosis. Alternatively, ST segment depression with or without T wave inversion is viewed as the dominant ECG feature of non-Q wave MI. However, this hypothesis has not been assessed prospectively in an acute MI population. We analyzed 2,304 serial ECGs at study entry (admission), day 2, day 3, and predischarge (mean, 10.2 +/- 2 days) from 576 patients with creatine kinase MB confirmed acute non-Q wave MI to determine what percentage of patients with early ST segment elevation culminated in subsequent Q wave development. Of this group, 187 patients (32%) exhibited 1 mm or greater ST segment elevation in two or more contiguous entry ECG leads. Of those patients whose non-Q wave MI could be localized on the basis of diagnostic admission ST segment shifts, the prevalence of early ST segment elevation was 43% (187 of 439). The sum total mean (+/- SD) peak ST segment elevation by lead group (anterior, inferior, lateral) was 4.0 +/- 2.4, 4.5 +/- 2.4, and 2.5 +/- 0.6 mm, respectively. Despite this, only 20% of patients with ST segment elevation (37 of 187) developed Q waves. Of 252 patients who exhibited early ST segment depression or T wave inversion or both, 39 (15%) evolved subsequent Q waves. Thus, while the prevalence of early ST segment elevation in acute evolving non-Q wave MI was higher than previously reported, 80% of patients with and 85% of patients without ST segment elevation and absent Q waves on the admission ECG did not develop subsequent Q waves during a 2-week period of observation (p = NS). In addition, when patients with ST segment elevation were compared with patients with ST segment depression or T wave inversions or both, there were no between-group differences in log peak creatine kinase (404 vs. 383 IU), reinfarction (6% vs. 8%), postinfarction angina (50% vs. 42%), or early recurrent ischemia (49% vs. 45%), defined as postinfarction angina with transient ECG changes. Thus, in patients who present with initial acute non-Q wave MI, ST segment shifts on admission are unreliable predictors of subsequent Q wave evolution and do not discriminate significant differences in postinfarction outcome. In particular, ST segment elevation during the early hours of evolving infarction is not an invariable harbinger of subsequent Q wave development.     

Predictors and importance of congestive heart failure in patients with acute inferior myocardial infarction

Inferior myocardial infarction (MI) is considered to have a more favorable prognosis than anterior wall MI but includes high risk groups with increased mortality and morbidity. It is well known that congestive heart failure (CHF) complicating acute MI has poor prognosis. In this study we assessed the clinical and prognostic significance of CHF and the predictive value of the baseline demographic and clinical variables for CHF in patients with acute inferior MI. A total of 350 patients with acute inferior MI were included. In group A there were 26 patients (7.4%) with CHF, and in group B there were 324 patients (92.6%) without this complication. Baseline clinical and demographic characteristics and in-hospital complications of the groups were assessed. In group A patients were older (67.6±9.5 vs 53.7±10.9 years, p<0.0001) and there were more female patients (50% vs 15%, p<0.00001) compared to group B. The prevalence of diabetes mellitus (58% vs 16%) and precordial ST segment depression on admission ECG (81% vs 50%) were significantly higher in group A compared to group B (p<0.00001 and p=0.002 consecutively). In group A there was a higher rate of righ ventricular (25% vs 23%), posterior (26% vs 24%) and posterolateral myocardial infarction (19% vs 14%), but the differences were not statistically different. In group A patients had significantly higher rate of second- or third-degree AV block (46% vs 8%, p<0.00001), cardiogenic shock (35% vs 1%, p<0.00001) and mortality (46% vs 3%, p<0.00001) compared to group B. In a multivariate regression analysis diabetes mellitus (p=0.0003) and precordial ST segment depression on admission ECG (p=0.002) were found as the independent predictors of in-hospital CHF in patients with acute inferior MI. CHF and ST segment depression on admission ECG were found as the independent predictors of in-hospital mortality (p<0.00001, p=0.04 consecutively). Patients with CHF complicating acute inferior MI have more unfavorable demographic and clinical characteristics on admission, higher rate of in-hospital complications and mortality. History of diabetes mellitus and precordial ST segment depression on admission ECG have an independent predictive value for CHF in this particular group of patients.     

Does saddle embolism influence short-term prognosis in patients with acute pulmonary embolism?

BACKGROUND: In some patients with acute pulmonary embolism (APE) thrombi may lodge at the levels of the bifurcation of pulmonary trunk and extend into both main pulmonary arteries, forming so-called saddle embolism (SE). AIM: To assess the incidence of SE and whether it is associated with an increased risk of complicated clinical course. METHODS: We studied 150 consecutive patients (94 females, 56 males) aged 63.6+/-16.7 years with APE confirmed with contrast enhanced spiral computed tomography or transesophageal echocardiography. RESULTS: SE was detected in 22 (14.7%) patients. Mean age (SE vs N-SE) was 64.3+/-17.4 vs 63.5+/-16.6 years, heart rate 100.8+/-14.1 beats/min vs 97.8+/-21.1 beats/min, systolic blood pressure 126.2+/-20.1 vs 127.1+/-23.3 mmHg and blood pulsoximetry 92 (68-98) vs 91 (30-98) % (all differences NS). In patients with SE, echocardiographic signs of the right ventricular overload, defined as right to left ventricular end - diastolic ratio >0.6 with right ventricular hypokinesia and/or maximal tricuspid peak systolic gradient >30 mmHg with shortened acceleration time of pulmonary ejection <80 ms, were more frequent (77.3% vs 51.6%, p=0.04), as was the mid-systolic deceleration of pulmonary ejection velocity (77.3% vs 49.2%, p=0.04). Mortality and complicated clinical course rates were similar in patients with SE or N-SE (mortality: 4.5% vs 13.3%, NS, and complicated clinical course: 34.4% vs 25.0%, NS). CONCLUSIONS: Saddle pulmonary embolism is frequent, especially in patients with echocardiographic signs of impaired pulmonary ejection pattern. Saddle embolism does not indicate unfavourable clinical outcome and probably should not influence treatment selection.     

急性肺栓塞不同危险分层与心电变化的关系

目的探究急性肺栓塞不同危险分层与心电变化的关系。方法选取2016年1月至2019年1月急性肺栓塞患者90例,根据危险分层进行分组。其中,低危组35例,中危组30例,高危组25例。均行心电图及动态心电图检查,心电图观察指标为心率、P波、QRS波群、T波、ST段变化,动态心电图观察指标心率变异性及心律失常。结果高危组窦性心动过速、肺型P波、SⅠQⅢTⅢ、ⅢST段抬高、V1ST段抬高、V1~V4T波倒置发生率均高于低危组,高危组ⅢST段抬高、V1ST段抬高、V1~V4T波倒置发生率高于中危组,差异均有统计学意义(均P<0.05)。高危组心率变异性指标正常RR间期标准差(SDNN)、每5min正常RR间期平均值的标准差SDANN均低于中、低危组,差异有统计学意义(均P<0.05)。高危组患者室性心律失常、室上性心律失常、房室传导阻滞及束支传导阻滞阳性率均高于中危组和低危组,差异均有统计学意义(均P<0.05)。结论急性肺栓塞时心电图改变与危险分层相关。     

Prognostic significance of ST segment depression in lateral leads I, aVL, V5 and V6 on the admission electrocardiogram in patients with a first acute myocardial infarction without ST segment elevation

OBJECTIVES

We sought to investigate the short-term prognostic value of the admission electrocardiogram (ECG) in patients with a first acute myocardial infarction (MI) without ST segment elevation.

BACKGROUND

ST segment depression on hospital admission predicts a worse outcome in patients with a first acute MI, but the prognostic information provided by the location of ST segment depression remains unclear.

METHODS

In 432 patients with a first acute MI without Q waves or ≥0.1 mV of ST segment elevation, we evaluated the ability of the initial ECG to predict in-hospital death.

RESULTS

The presence, magnitude and extent of ST segment depression were associated with an increased mortality, but the only electrocardiographic variable that was significant in predicting death after adjusting for baseline predictors was ST segment depression in two or more lateral (I, aVL, V₅, or V₆) leads (odds ratio 3.5, 95% confidence interval 1.2 to 10.6). Patients with lateral ST segment depression (n = 91, 21%) had higher rates of death (14.3% vs. 2.6%, p < 0.001), severe heart failure (14.3% vs. 4.1%, p < 0.001) and angina with electrocardiographic changes (20.0% vs. 11.6%, p = 0.04) than did the remaining patients, even though they had similar peak creatine kinase, MB fraction levels (129 ± 96 vs. 122 ± 92 IU/liter, p = NS). In contrast, ST segment depression not involving the lateral leads did not predict a poor outcome. Among patients who were catheterized, those with lateral ST segment depression had a lower left ventricular ejection fraction (57 ± 12% vs. 66 ± 13%, p = 0.001) and more frequent left main coronary artery or three-vessel disease than did the remaining patients (60% vs. 22%, p < 0.001).

CONCLUSIONS

In patients with a first non–ST segment elevation acute MI, ST segment depression in the lateral leads on hospital admission predicts a poor in-hospital outcome.     

Prognostic significance of ST segment depression in lateral leads I, aVL, V5 and V6 on the admission electrocardiogram in patients with a first acute myocardial infarction without ST segment elevation

OBJECTIVESWe sought to investigate the short-term prognostic value of the admission electrocardiogram (ECG) in patients with a first acute myocardial infarction (MI) without ST segment elevation.BACKGROUNDST segment depression on hospital admission predicts a worse outcome in patients with a first acute MI, but the prognostic information provided by the location of ST segment depression remains unclear.METHODSIn 432 patients with a first acute MI without Q waves or ≥0.1 mV of ST segment elevation, we evaluated the ability of the initial ECG to predict in-hospital death.RESULTSThe presence, magnitude and extent of ST segment depression were associated with an increased mortality, but the only electrocardiographic variable that was significant in predicting death after adjusting for baseline predictors was ST segment depression in two or more lateral (I, aVL, V₅, or V₆) leads (odds ratio 3.5, 95% confidence interval 1.2 to 10.6). Patients with lateral ST segment depression (n = 91, 21%) had higher rates of death (14.3% vs. 2.6%, p < 0.001), severe heart failure (14.3% vs. 4.1%, p < 0.001) and angina with electrocardiographic changes (20.0% vs. 11.6%, p = 0.04) than did the remaining patients, even though they had similar peak creatine kinase, MB fraction levels (129 ± 96 vs. 122 ± 92 IU/liter, p = NS). In contrast, ST segment depression not involving the lateral leads did not predict a poor outcome. Among patients who were catheterized, those with lateral ST segment depression had a lower left ventricular ejection fraction (57 ± 12% vs. 66 ± 13%, p = 0.001) and more frequent left main coronary artery or three-vessel disease than did the remaining patients (60% vs. 22%, p < 0.001).CONCLUSIONSIn patients with a first non–ST segment elevation acute MI, ST segment depression in the lateral leads on hospital admission predicts a poor in-hospital outcome.     

Q-wave evolution of a first acute myocardial infarction without significant ST segment elevation

BACKGROUND: Some patients with acute myocardial infarction presenting without significant ST segment elevation develop a Q-wave infarction. It is unclear whether these patients can be identified from the admission electrocardiogram (ECG) and whether they differ in their in-hospital prognosis from those who retain a non-Q-wave myocardial infarction. METHODS: In 432 consecutive patients admitted to our centre with a first acute myocardial infarction without Q waves and with ST segment amplitudes < or =0.1 mV on admission, we assessed the frequency, the electrocardiographic predictors and the short-term implications of a Q-wave evolution. RESULTS: In 94 patients (22%), a Q-wave myocardial infarction evolved before hospital discharge (14 anterior, 26 inferior, six lateral, and 48 posterior). Minor anterior ST segment elevation was 36% sensitive and 95% specific in predicting anterior Q waves; minor inferior ST segment elevation, 42% and 89%, respectively, for inferior Q waves; and a maximal ST segment depression > or =0.2 mV in leads V2-V3 with upright T waves and without remote ST segment depression, 38% and 97%, respectively, for posterior R waves. Although patients with a Q-wave evolution had a greater creatinkinase MB peak than those retaining a non-Q-wave pattern (191+/-113 vs. 105+/-77 IU/l, respectively, P<0.001), they experienced a benign in-hospital course, with similar risk of severe complications after adjustment for the baseline clinical predictors than non-Q-wave patients. CONCLUSIONS: About one fifth of patients with a first acute myocardial infarction without a significant ST segment elevation develop a Q-wave infarction and the admission ECG can help identify them. This evolution, however, is not associated with a worse in-hospital outcome.     

Early continuous ST segment monitoring in unstable angina: prognostic value additional to the clinical characteristics and the admission electrocardiogram.

BACKGROUND AND OBJECTIVE: In unstable angina, clinical characteristics, resting electrocardiography, and early continuous ST segment monitoring have been individually reported to identify subgroups at increased risk of adverse outcome. It is not known, however, whether continuous ST monitoring provides additional prognostic information in such a setting. DESIGN: Observational study of 212 patients with unstable angina without evidence of acute myocardial infarction admitted to district general hospitals, who had participated in a randomised study comparing heparin and aspirin treatment versus aspirin alone. METHODS: Clinical variables and a 12 lead electrocardiogram (ECG) were recorded at admission, and treatment was standardised to include aspirin, atenolol, diltiazem, and intravenous glyceryl trinitrate, in addition to intravenous heparin (randomised treatment). Continuous ST segment monitoring was performed for 48 h and all inhospital adverse events were recorded. RESULTS: The admission ECG was normal in 61 patients (29%), showed ST depression in 59 (28%) (17 > or = 0.1 mV), and T wave changes in a further 69 (33%). The remaining 23 had Q waves (18), right bundle branch block (four), or ST elevation (one). During 8963 h of continuous ST segment monitoring (mean 42.3 h/patient), 132 episodes of transient myocardial ischaemia (104 silent) were recorded in 32 patients (15%). Forty patients (19%) had an adverse event (cardiac deaths (n = 3), non-fatal myocardial infarction (n = 6) and, emergency revascularisation (n = 31)). Both admission ECG ST depression (P = 0.02), and transient ischaemia (P < 0.001) predicted an increased risk of non-fatal myocardial infarction or death, while no patients with a normal ECG died or had a myocardial infarction. Adverse outcome was predicted by admission ECG ST depression (regardless of severity) (odds ratio (OR) 3.41) (P < 0.001), and maintenance beta blocker treatment (OR 2.95) (P < 0.01). A normal ECG predicted a favourable outcome (OR 0.38) (P = 0.04), while T wave or other ECG changes were not predictive of outcome. Transient ischaemia was the strongest predictor of adverse prognosis (OR 4.61) (P < 0.001), retaining independent predictive value in multivariate analysis (OR 2.94) (P = 0.03), as did maintenance beta blocker treatment (OR 2.85) (P = 0.01) and admission ECG ST depression, which showed a trend towards independent predictive value (OR 2.11) (P = 0.076). CONCLUSIONS: Patients with unstable angina and a normal admission ECG have a good prognosis, while ST segment depression predicts an adverse outcome. Transient myocardial ischaemia detected by continuous ST segment monitoring in such patients receiving optimal medical treatment provides prognostic information additional to that gleaned from the clinical characteristics or the admission ECG.     

急性肺栓塞溶栓疗效及溶栓前后NT-proBNP的变化

目的:观察瑞替普酶对急性肺栓塞(APE)患者溶栓治疗的临床疗效及溶栓前后血浆N端B型尿钠肽前体(NT-proBNP)水平的变化及其临床意义。方法:42例符合溶栓治疗条件的APE患者给予瑞替普酶18mg+18mg静脉溶栓治疗,分别观察溶栓前及溶栓6h后患者临床表现、血浆NT-proBNP、肌钙蛋白T(cTnT)水平,溶栓12～24h复查超声心动图、CT肺动脉成像或核素肺灌注显像,评价临床疗效。结果:血管再通患者37例(88.1%),其NT-proBNP浓度和肺动脉压力均较溶栓前显著下降[(8 672.4±201.7)pg/ml︰(1 559.8±23.5)pg/ml,(52.82±17.34)mmHg︰(38.13±12.32)mmHg,1mmHg=0.133kPa;均P<0.01)],且NT-proBNP浓度下降幅度与肺动脉压下降幅度、右心室/左心室比值密切相关(r分别为0.61、0.54);溶栓前后cTnT水平差异无统计学意义。血管未通患者5例,其溶栓前后NT-proBNP、cTnT及肺动脉压力差异无统计学意义。结论:瑞替普酶对APE患者进行静脉溶栓治疗有较好的临床疗效和安全性,且动态检测NT-proBNP浓度可作为评价溶栓再灌注成功与否的有效指标。     

Admission risk assessment by cardiac troponin T in unstable coronary artery disease: additional prognostic information from continuous ST segment monitoring. TRIM study group. Thrombin Inhibition in Myocardial Ischemia.

OBJECTIVES: We investigated whether the addition of 24 h of continuous vectorcardiography ST segment monitoring (cVST) for an early (within 24 h of the latest episode of angina) determination of cardiac troponin T (cTnT) could provide additional prognostic information in patients with unstable coronary artery disease (UCAD), i.e., unstable angina and non-Q wave myocardial infarction. BACKGROUND: Determination of cTnT at admission and cVST are individually reported to be valuable techniques for the risk assessment of patients with UCAD. METHODS: Two hundred and thirty-two patients suspected of UCAD were studied. Patients were followed for 30 days, and the occurrence of cardiac death or acute myocardial infarction (AMI) were registered. RESULTS: One ST segment episode or more (relative risk [RR] 7.43, p = 0.012), a cTnT level > or = 0.20 microg/liter (RR 3.85, p = 0.036) or prestudy medication with calcium antagonists (RR 3.31, p = 0.041) were found to carry independent prognostic information after multivariate analysis of potential risk variables. By combining a cTnT determination and subsequent cVST for 24 h, subgroups of patients at high (25.8%) (n = 31), intermediate (3.1%) (n = 65) and low risk (1.7%) (n = 117) of death or AMI could be identified. CONCLUSIONS: Twenty-four hours of cVST provides additional prognostic information to that of an early cTnT determination in patients suspected of having UCAD. The combination of biochemical and electrocardiographic methods provides powerful and accurate risk stratification in UCAD.     

Myocardial ischemia during daily activities: the importance of increased myocardial oxygen demand

The role of increased myocardial oxygen demand in the pathophysiology of myocardial ischemia occurring during daily activities was evaluated in 50 patients with coronary artery disease and exercise-induced ST segment depression. Each patient underwent ambulatory electrocardiographic (ECG) monitoring for ST segment shifts during normal daily activities and symptom-limited bicycle exercise testing with continuous ECG monitoring. All 50 patients had ST depression greater than or equal to 0.1 mV during exercise. A total of 241 episodes of ST depression were noted in the ambulatory setting in 31 patients; only 6% of these were accompanied by angina pectoris. Significant (0.1 mV) ST depression during ambulatory monitoring was preceded by a mean increase in heart rate of 27 +/- 12 beats/min. Patients with ischemia during daily activities developed ST depression earlier during exercise (7.9 +/- 4.4 vs. 14.2 +/- 6.4 min, p less than 0.001) and tended to have significant ECG changes at a lower exercise heart rate and rate-pressure product than did those without ST depression during ambulatory monitoring. In the 31 patients with ischemia during daily activities, the mean heart rate associated with ST depression in the ambulatory setting was closely correlated with the heart rate precipitating ECG changes during exercise testing (r = 0.74, p less than 0.001).(ABSTRACT TRUNCATED AT 250 WORDS)     

Electrocardiographic Criteria for ST-Elevation Myocardial Infarction in Patients With Left Ventricular Hypertrophy

Patients with electrocardiographic (ECG) left ventricular hypertrophy (LVH) have repolarization abnormalities of the ST segment that may be confused with an ischemic current of injury. We analyzed the ACTIVATE-SF database, a registry of consecutive emergency department ST-segment elevation (STE) myocardial infarction diagnoses from 2 medical centers. Univariate analysis was performed to identify ECG variables associated with presence of an angiographic culprit lesion. Recursive partitioning was then applied to identify a clinical decision-making rule that maximizes sensitivity and specificity for presence of an angiographic culprit lesion. Seventy-nine patients with ECG LVH underwent emergency cardiac catheterization for primary angioplasty. Patients with a culprit lesion had greater magnitude of STE (3.0 ± 1.8 vs 1.9 ± 1.0 mm, p = 0.005), more leads with STE (3.1 ± 1.6 vs 2.0 ± 1.8 leads, p = 0.002), and a greater ratio of STE to R-S-wave magnitude (median 25% vs 9.2%, p = 0.003). Univariate application of ECG criteria had limited sensitivity and a high false-positive rate for identifying patients with an angiographic culprit lesion. In patients with anterior territory STE, using a ratio of ST segment to R-S-wave magnitude ≥25% as a diagnostic criteria for STE myocardial infarction significantly improved specificity for an angiographic culprit lesion without decreasing sensitivity (c-statistic 0.82), with a net reclassification improvement of 37%. In conclusion, application of an ST segment to R-S-wave magnitude ≥25% rule may augment current criteria for determining which patients with ECG LVH should undergo primary angioplasty.