Prognostic value of ischemia monitoring with on-line vectorcardiography in patients with unstable coronary artery disease

AIM: The aim of this study was to determine whether on-line vectorcardiography (VCG) gives independent prognostic information, regarding death, myocardial infarction (MI), and revascularization in patients with unstable coronary artery disease, i.e. unstable angina or non-Q-wave MI. METHODS AND RESULTS: One hundred and fifty patients (mean age 69 +/- 10), participating in a randomized study of low-molecular-weight heparin in unstable coronary artery disease, were studied with on-line VCG recordings for 24 h. During a 5-6-month follow-up, 11 patients died, 14 suffered a nonfatal MI and 31 were revascularized. Univariate predictors of death were diabetes mellitus (p < 0.01), maximum ST vector magnitude (ST-VM; p < 0.001), maximum ST change vector magnitude (STC-VM; p < 0.001), number of ST-VM (p < 0.01) and STC-VM episodes (p < 0.001). In multivariate analysis, the number of STC-VM episodes (p < 0.01) and diabetes mellitus (p < 0.02) each gave independent prognostic information regarding death. When all cardiovascular events were combined, the inability to perform an exercise test (p < 0.05), maximum value of ST-VM (p < 0.01) and STC-VM (p < 0.001), the number of episodes of STC-VM (p < 0.001) and ST-VM (p < 0.001) all gave prognostic information. In multivariate analysis, the inability to perform an exercise test and the number of STC-VM episodes were independent predictors. CONCLUSION: VCG monitoring during the first 24 h of hospitalization for unstable coronary artery disease gives independent prognostic information.     

Ischemia monitoring with on-line vectorcardiography compared with results from a predischarge exercise test in patients with acute ischemic heart disease

Information from 24-hour monitoring with on-line vectorcardiography, starting immediately after admission, was compared with results from a predischarge exercise test 3–13 days after admission. A total of 169 patients with acute myocardial infarction and 73 patients with unstable angina pectoris were investigated. Patients were followed for 487 ± 135 days. During the follow-up period, 19 patients (8%) died from cardiac causes and 34 (14%) were hospitalized for a myocardial infarction. The QRS vector difference (QRS-VD), ST change vector magnitude (STC-VM), ST vector magnitude (ST-VM), and ST vector leads X, Y, Z were monitored. Patients with ST depression on the exercise test showed higher occurrence of transient, supposedly ischemic, episodes of QRS-VD, STC-VM, and ST-VM than patients without ST depression. The sensitivity and specificity of identifying patients with ST depression at the exercise test were respectively, 71 and 47% for QRS-VD episodes, 58 and 56% for ST-VM episodes, and 55 and 65% for STC-VM episodes. The maximum ST depression at the exercise test was related to the maximum ST depression in vector lead X (r = .44, P < .001) and the number of STC-VM (r = .40, P < .001), ST-VM (r = .37, P < .001), and QRS-VD (r = .33, P < .001) episodes on the VCG. In multivariate analysis, maximum ST depression in vector lead X and STC-VM episodes were the best determinants for ST depression at the exercise test. In a Cox regression model, the optimal combination of exercise test data in patients who died from cardiac causes exhibited a global chi-square value of 20.0. The combination of these data and the number of STC-VM episodes increased the global chi-square value to 30.6. This study indicates that in patients with acute ischemic heart disease, early continuous vectorcardiographic monitoring may predict the results from a predischarge exercise test and also contributes independent prognostic information beyond that of exercise test data.     

On-line vectorcardiography during elective coronary angioplasty indicates procedure-related myocardial infarction

BACKGROUND: Increased creatine kinase concentrations after elective percutaneous transluminal coronary angioplasty (PTCA) have been shown to be associated with increased late cardiac mortality. OBJECTIVE: To evaluate the potential of continuous on-line vectorcardiography during elective PTCA to identify procedure-related myocardial infarction. METHODS: Patients (n = 192, ages 58 +/- 10 years), treated with elective and initially successful PTCA, were studied using vectorcardiogram (VCG) recordings. VCG monitoring was started 5 min before start of the PTCA and was carried out during the entire procedure, for at least 30 min after the first balloon inflation. ST-segment vector magnitude (ST-VM) and ST-segment change vector magnitude (STC-VM) were monitored. RESULTS: Fifteen (7.8%) procedure-related myocardial infarctions occurred. Indicators of procedure-related myocardial infarction were maximum value of ST-VM (P < 0.001) and STC-VM (P < 0.001), total ischemic time of all ST-VM episodes (P < 0.001) and STC-VM episodes (P < 0.001). The variable most closely related to a procedure-related myocardial infarction was the maximum STC-VM value during the procedure. With an optimized cutoff value, maximum STC-VM predicts a procedure-related myocardial infarction with a sensitivity of 93%, a specificity of 59% and a negative predictive value of 99%. Patients who had a stent implanted had significantly greater VCG values (P < 0.05-P < 0.001) than the group without a stent. There was a trend (P < 0.06) to a relation between increased creatine kinase concentration and stent implantation. In patients both with and without an implanted stent, greater STC-VM values were associated with procedure-related myocardial infarction (P < 0.01). CONCLUSION: Continuous VCG monitoring during elective PTCA is a promising method for immediate detection of patients at increased risk of procedure-related myocardial infarction.     

Prognostic role of on-line vectorcardiography as regards repeat revascularization after successful coronary angioplasty

This study evaluated the prognostic significance of continuous on-line vectorcardiography (VCG) during elective coronary angioplasty (percutaneous transluminal coronary angioplasty, PTCA). Patients (n = 192, mean age 58 +/- 10), treated with elective and initially successful PTCA, were included. VCG monitoring was started before start of the PTCA procedure and was carried out during the entire procedure. ST vector magnitude (ST-VM) was monitored. A 6-month follow-up was obtained. Main outcome measures were the frequency of cardiac events and revascularization during follow-up. During follow-up, 1 patient died, 6 suffered a nonfatal myocardial infarction and 50 were revascularized. Angiography revealed restenosis in 88% of the patients who had a revascularization. In the total patient group, the VCG predictor of revascularization was the total ischemic time of all ST-VM episodes (p = 0.05). Clinical predictors of revascularization were diabetes mellitus (p < 0.01), a more severe type of lesion (type B; p < 0.01), percent post-PTCA stenosis (p < 0.05), nominal balloon size (p < 0.01), maximum balloon pressure (p < 0.05) and no stent implanted (p < 0.001). In a multivariate analysis all the above significant univariate variables of revascularization were entered. Total ischemic time of ST-VM (p < 0.01) was the best variable giving independent prognostic information. In the nonstent group, total ischemic time of ST-VM (p < 0.01) was the only independent predictor of a further revascularization. In conclusion, VCG monitoring during elective PTCA gives on-line information that identifies patients at an increased risk of a revascularization during 6 months after the initial procedure.     

Women react with more myocardial ischemia and angina pectoris during elective percutaneous transluminal coronary angioplasty

BACKGROUND: Women have been considered to be at higher risk of complications relating to percutaneous transluminal coronary angioplasty (PTCA) than are men. One reason for this sex-related difference could be the ischemic response of myocardium during the procedure. OBJECTIVE: To investigate whether there are sex-related differences in ischemic response of myocardium during elective PTCA. METHODS: Consecutive patients (n = 192, of whom 48 were women), were subjected to vectorcardiography during the PTCA procedure. Vectorcardiographic variables, magnitude of ST-segment vector (ST-VM), and magnitude of ST-segment vector change (STC-VM) were studied. RESULTS: Women were older (63 +/- 10 versus 56 +/- 10 years, P< 0.001) than men in our study and more often had diabetes mellitus and hypertension. Women less often had stents implanted (24 versus 50%, P < 0.01) and they were subjected to fewer balloon inflations (P < 0.001), with a total inflation time shorter than that for men (P< 0.001). Maximum STC-VM was 25% greater for women (P < 0.05). Women reported greater maximum pain (P < 0.05) and nitroglycerine was more frequently used for them during PTCA (P < 0.05). Occurrence of episodes of residual ischemic STC-VM (the difference between total number of episodes and number of balloon inflations) was more common for women (3 +/- 5 versus 1 +/- 3, P< 0.01). Duration of residual ischemic STC-VM episodes (the difference between total duration of episodes and duration of balloon inflations) was longer for women than it was for men (242 +/- 275 versus 148 +/- 233 s, P < 0.05). In a stepwise multivariate analysis and for a matched case-control group, episodes of residual STC-VM and duration of residual STC-VM episodes still indicated that there was an independent sex-related difference (P < 0.01 and P < 0.01, respectively). CONCLUSIONS: Women more commonly develop vectorcardiographic signs of severe myocardial ischemia, more frequently experience episodes of ischemia and report more severe angina pectoris during elective PTCA than do men.     

Relative contributions of a single-admission 12-lead electrocardiogram and early 24-hour continuous electrocardiographic monitoring for early risk stratification in patients with unstable coronary artery disease

Patients with unstable coronary syndromes are a heterogeneous group with varying degrees of ischemia and prognosis. The present study compares the prognostic value of a standard electrocardiogram (ECG) obtained at admission to the hospital with the information from 24-hour continuous electrocardiographic monitoring obtained immediately after admission. The admission ECGs and 24 hours of vectorcardiographic (VCG) monitoring from 308 patients admitted with unstable coronary artery disease were analyzed centrally regarding standard electrocardiographic ST-T changes, ST-vector magnitude (ST-VM), and ST change vector magnitude episodes. End points were death, acute myocardial infarction, and refractory angina pectoris within a 30-day follow-up period. ST-VM episodes (> or = 50 microV for > or = 1 minute) during VCG monitoring was the only independent predictor of death or acute myocardial infarction by multivariate analysis. ST-VM episodes during vectorcardiography was associated with a relative risk of 12.7 for having a cardiac event, hypertension was associated with a relative risk of 1.7, and ST depression on the admission ECG was associated with a relative risk of 5.7. Patients with ST depression at admission had an event rate (death or acute myocardial infarction) of 17% at 30-day follow-up. Patients without ST depression could further be risk stratified by 24 hours of VCG monitoring into a subgroup with ST-VM episodes at similar (8%) risk and a subgroup without ST-VM episodes at low (1%) risk (p = 0.00005). Continuous VCG monitoring provides important information for evaluating patients with unstable coronary artery disease. It is recommended that patients not initially estimated at high risk based on the admission ECG are referred for 24 hours of VCG monitoring for further risk stratification.     

Quantitative and temporal relation between the release of myoglobin and creatine kinase and the evolution of vectorcardiographic changes during acute myocardial infarction in man

The relation in time and magnitude between QRS vector changes (QRS-VD), ST vectors (ST-VM), and the cumulated release of myoglobin, total creatine kinase, and creatine kinase isoenzyme MB was studied. Seventy four patients with a first myocardial infarction and a history of symptoms of up to 5 h were included. Blood samples for enzyme analysis were taken every 4-6 h for 72 h and cumulated enzyme release was calculated from a monocompartmental first order model. QRS-VD and ST-VM were determined every 10 min for 24 h by computer analysis of Frank lead vectorcardiograms. Infarct sizes were visually determined from the different enzymatic and vectorcardiographic evolution curves. Eight patients were excluded from the analysis because they had a QRS width greater than or equal to 120 ms or ill defined plateaus of the release curves. The relation between infarct sizes estimated from QRS-VD and total creatine kinase was r = 0.62; QRS-VD and myoglobin release r = 0.57; total creatine kinase and myoglobin release r = 0.72, showing that these variables are good and complementary indices for estimating myocardial infarct size. Median infarct evolution curves were computed after the individual curves were normalised to 100%. ST-VM fell rapidly during the first 7 h to 40% of the initial values. QRS-VD and myoglobin release were closely associated and completed their development on average 15 h after the onset of symptoms.(ABSTRACT TRUNCATED AT 250 WORDS)     

Evolution of vectorcardiographic QRS changes during myocardial infarction in dogs and their relation to infarct size

The ability of vectorcardiographic QRS changes to quantify myocardial ischaemia and necrosis in dogs was studied. Myocardial infarction was produced in 21 anaesthetised dogs by inflating a balloon inserted into the right, left anterior descending, or left circumflex coronary artery. A Frank vectorcardiogram was recorded before and every 15-30 minutes for 10 hours after the occlusion. ST vector magnitude (ST-VM), QRS summation vectors, and QRS integral differences (QRS-VD) between the preocclusion recording and subsequent recordings were computed. Twenty four hours after occlusion two vectorcardiograms were obtained, the hearts removed, and the infarcts cut out and weighed. Four dogs were excluded from the study because of persistent arrhythmias, major conduction defects, or sudden death. In the remaining 17 dogs the QRS summation vectors rotated maximally towards the site of infarction 7 minutes after occlusion corresponding to a median minimum QRS-VD of -19 (range -2 to -29) microVs. This coincided with the maximum ST-VM, median 0.43 (range 0.12-0.68) mV. The QRS summation vectors subsequently rotated away from the infarct producing a median maximum QRS-VD of 20 (range 6-28) microVs. The maximum QRS-VD correlated significantly with the percentage of infarcted myocardium (r = 0.82). The correlation between the early minimum QRS-VD and the maximum ST-VM was r = 0.83. The QRS-VD was recomputed with a reference taken 2 or 4 hours after occlusion. The relation between maximum QRS-VD and infarct percentage was not significantly changed with the reference at 2 hours, but with the reference at 4 hours the ability to predict infarct size was lost.(ABSTRACT TRUNCATED AT 250 WORDS)     

Positional changes of spatial QRS- and ST-segment variables in normal subjects: implications for continuous vectorcardiography monitoring during myocardial ischemia

Electrocardiographic QRS- and ST-segment changes are to be expected during changes in body posture. We prospectively analyzed the influence of changes in body position on continuous vectorcardiography monitoring of QRS-vector difference (QRS-VD) and ST change-vector magnitude (STC-VM) according to the currently used criteria of myocardial ischemia in 21 normal subjects. Fifteen (71%) and 6 (29%) subjects had significant positional QRS-VD and STC-VM changes, respectively. Vectorcardiography changes were most frequent and pronounced in the left lateral position. An alternative to the existing criterion of ischemia is proposed to improve the specificity of STC-VM. Subjects with positional QRS-VD changes had higher mean STC-VM values as compared with those without such changes. Otherwise no characteristics among those with positional vectorcardiography changes could be identified. There was no statistically significant association between positional QRS-VD and STC-VM changes (R = .13, P = .57). We conclude that the clinical use of QRS-VD in its present form for continuous vectorcardiography monitoring of myocardial ischemia seems to be of limited practical value, because of the presence of frequent "pseudo-ischemic" changes. STC-VM seems to have a significant potential of continuous vectorcardiography monitoring. However, an indicator of body position change or even an algorithm enabling on-line correction for positional vectorcardiography changes seems to be essential to improve the accuracy of this technique in identifying myocardial ischemia.     

Assessment of left ventricular hypertrophy by ECG and VCG in patients with inferior and posterior myocardial infarction. A comparison with echocardiographic data

Electrocardiographic (ECG) and vectorcardiographic (VCG) QRS voltage criteria have been analyzed in 26 patients with inferior and 17 with posterior myocardial infarction (MI) in comparison with left ventricular (LV) mass and global and regional wall motion as assessed by M-mode and two-dimensional (2D) echocardiography. Transverse plane QRS maximal vector correlated significantly with LV mass in patients with both inferior and posterior MI (r = 0.65 and 0.87, respectively, p less than 0.01). A transverse plane QRS maximal vector greater than 1.5 mV correctly recognized 12 of 15 (80%) and 9 of 12 (75%) patients with respectively inferior and posterior MI and LV mass greater than 221 gm. Of the ECG measurements, S V1-2 + R V5-6 correlated moderately with LV mass in patients with inferior MI (r = 0.47), and R V1-2 + R V5-6 correlated moderately with LV mass in those with posterior MI (r = 0.67). ECG and VCG QRS voltage data did not correlate with global and regional LV function as assessed by M-mode and 2D echocardiography. We conclude that: ECG and VCG QRS voltage parameters can be utilized for assessing non-invasively LV enlargement in patients with postero-inferior MI; ECG and VCG QRS voltage parameters should be utilized with caution for analyzing LV function or MI size in postero-inferior MI.     

ST-segment monitoring with continuous 12-lead ECG improves early risk stratification in patients with chest pain and ECG nondiagnostic of acute myocardial infarction.

OBJECTIVES: The purpose of this study was to evaluate the prognostic importance of ischemic episodes detected by ST-segment monitoring with continuous 12-lead electrocardiography (ECG) in a nonselected coronary care unit (CCU) population with chest pain and ECG nondiagnostic of acute myocardial infarction (AMI). BACKGROUND: Patients with chest pain and ECG nondiagnostic of AMI constitute a heterogeneous group concerning both diagnosis and prognosis. Continuous 12-lead ECG is a rather new method not thoroughly studied in this population. METHODS: The ST-segment monitoring with continuous 12-lead ECG was performed for 12 h in 630 consecutive patients admitted to CCU due to chest pain and a nondiagnostic ECG, i.e., no ST-segment elevations. An ST-episode was defined as a transient ST-segment depression or elevation of at least 0.10 mV. The median follow-up time was six months. RESULTS: A total of 176 ST-episodes occurred in 100 (15.9%) patients. The median duration and maximal ST-segment deviation in patients with ST-episodes were 80 min and 0.20 mV, respectively. Presence of ST-episodes predicted worse outcome concerning cardiac death and cardiac death or myocardial infarction (MI) (log-rank p < 0.001). At 30 day follow-up procedure, 10% versus 1.5% died from cardiac causes or had an MI in the group with and without ST-episodes, respectively. In a multivariate analysis, only troponin T > or = 0.10 microg/l and the presence of ST-episodes came out as independent predictors of cardiac death or MI. CONCLUSIONS: Continuous 12-lead ECG monitoring provides prognostic information on-line and considerably improves early risk stratification in patients with ECG nondiagnostic of AMI and symptoms suggestive of acute coronary syndrome.     

Coronary collateral circulation is less developed when ischaemic heart disease coexists with diabetes

BACKGROUND: The extent of myocardial ischaemia and the magnitude of systolic function impairment following myocardial infarction (MI) depend to a large degree on the performance of coronary collateral circulation. Endothelial function is altered in several disorders, including diabetes. An impaired development of coronary collateral circulation may be a factor responsible for post-MI complications in patients with diabetes. AIM: To compare the degree of coronary collateral circulation development between patients with advanced ischaemic heart disease (IHD), with or without diabetes. METHODS: The study group consisted of 70 consecutive patients with diabetes who underwent coronary angiography between September 1998 and December 1999 and had total occlusion of at least one of the main coronary vessels. The control group consisted of 70 age-, gender, and MI history-matched non-diabetic patients. Coronary collateral circulation was assessed using the collateral score (CS). RESULTS: Patients with diabetes had less developed coronary collateral circulation than the patients without diabetes which was reflected by a significantly lower CS value - 1.47+/-1.56 vs 2.03+/-1.81; p < 0.05. No significant relationship was found between CS and age, gender, body mass index, history of MI or the presence of IHD risk factors. There was a significant association between the number of vessels with lesions and CS: r=0.40, p=0.0006 in the control group and r=0.42, p=0.0003 in patients with diabetes. The CS values in patients with single-, two- or three-vessel disease were 1.27+/-1.34, 2.38+/-1.85 and 2.98+/-2.07 in the control group, and 0.70+/-0.90, 1.10+/-1.30 and 2.23+/-1.76 in patients with diabetes, respectively. A multivariate analysis revealed that the presence of diabetes (t=-3.04, p=0.003) and the number of affected vessels (t=5.23, p=0.0001) were independently related to the CS values. CONCLUSIONS: Patients with IHD and diabetes have less developed coronary collateral circulation than IHD patients without diabetes, regardless of the extent of coronary lesions. Patients with diabetes who undergo coronary angiography, have more advanced coronary atherosclerotic lesions than patients without diabetes.     

Three-dimensional vectorcardiography (3-D VCG) by computer graphics in old myocardial infarction

By using computer graphics we rotated the vector loop and three coordinate axes to find the viewpoint where the infarctional changes are maximally exposed and demonstrated the advantage of the "3-D VCG" over the conventional VCG by defining the quantitative "MI index." The orthogonal electrocardiogram recorded by the Frank lead system was digitally measured and processed by a microcomputer. The loops and axes were rotated about the X axis (X-rot) and the Y axis (Y-rot). The spatial vector loop and orthogonal coordinates can be presented as viewed from any spheric direction. Eight quadrants were illustrated with four colors and red circles. The subjects consisted of 30 patients with old anterior myocardial infarction (MI) and 15 patients with old inferior MI. We measured the area of "Bite" in anterior MI and superior displacement in inferior MI. The MI index was defined and averaged in 361 directions. In anterior MI, the maximum mean index was obtained when X-rot is +90 degrees and Y-rot -40 degrees, viewed from upward and leftward, whereas in inferior MI it was obtained when X-rot is -50 degrees and Y-rot -80 degrees, viewed from downward and leftward. These values were significantly higher than those in conventional VCG projections, substantiating superior diagnostic sensitivity of 3-D VCG.     

Clinical usefulness of a functional test of neutralising streptokinase antibodies for the prediction of the thrombolytic effect of streptokinase in acute myocardial infarction

We investigated whether the occurrence of neutralising streptokinase (SK) antibodies, as assessed by a new bedside test, was related to the effect of SK in acute myocardial infarction (AMI), assessed with continuous vectorcardiography (VCG). Twenty-eight patients with ST elevation, admitted 相似文献   

A prospective, placebo-controlled, randomized trial of intravenous streptokinase and angioplasty versus lone angioplasty therapy of acute myocardial infarction.

BACKGROUND. The value of routine administration of intravenous thrombolytic agents during percutaneous transluminal coronary angioplasty (PTCA) therapy of acute myocardial infarction (MI) has not been determined. Therefore, we prospectively randomized 122 patients with evolving MI to PTCA therapy with or without adjunctive intravenous streptokinase therapy. METHODS AND RESULTS. Patients with ECG ST segment elevation who presented within 4 hours of symptom onset, had no contraindication to thrombolytic therapy, and were not in cardiogenic shock were enrolled. They were treated immediately with intravenous heparin (10,000 units) and oral aspirin (325 mg) and randomized to treatment with placebo or streptokinase (1.5 M units) administered intravenously over 30 minutes. Patients then were taken immediately to the catheterization laboratory, and those with suitable coronary anatomy underwent immediate PTCA. Subsequent clinical course, serial radionuclide ventriculography, and 6-month repeat angiography were analyzed. A total of 106 patients were treated with PTCA. Use of PTCA was similar for placebo (92%) and streptokinase (83%) groups. Angioplasty was successful in 95% of patients, with no difference in placebo (93%) and streptokinase (98%) groups. Serial radionuclide ventriculography demonstrated no difference in 24-hour (52 +/- 12% versus 50 +/- 12%) or 6-week (51 +/- 12% versus 51 +/- 13%) ejection fraction values for placebo and streptokinase groups, respectively. Contrast ventriculography demonstrated improvement in immediate (54 +/- 12%) versus 6-month (60 +/- 15%, p < 0.05) values for the overall group. No differences in 6-month values were present (58 +/- 15% versus 62 +/- 15%, p = NS) for placebo and streptokinase groups, respectively. Coronary angiography was performed in 75% of the 90 patients eligible for restudy. Arterial patency was 87% at 6 months, and coronary restenosis was present in 38% of patients. No differences in chronic patency or restenosis were detected for the two treatment groups. Although adjunctive intravenous streptokinase therapy did not improve outcome, it did complicate the hospital course. Hospitalization was longer (9.3 +/- 5.0 versus 7.7 +/- 4.4 days, p = 0.046) and more costly ($25,191 +/- 15,368 versus $19,643 +/- 7,250, p < 0.02). Transfusion rate was higher (39% versus 8%, p = 0.0001) and need for emergency coronary bypass surgery was greater (10.3% versus 1.6%, p = 0.03) for the streptokinase-treated patients. CONCLUSIONS. Adjunctive intravenous streptokinase therapy does not enhance early preservation of ventricular function, improve arterial patency rates, or lower restenosis rates after PTCA therapy of acute MI. Hospital course is longer, more expensive, and more complicated. For these reasons, PTCA therapy of acute MI should not be routinely performed with adjunctive intravenous streptokinase therapy.     

Chest pain in acute myocardial infarction: a descriptive study according to subjective assessment and morphine requirement

In 722 patients with suspected acute myocardial infarction (MI) we have tried to describe the course of chest pain according to their own assessment and morphine requirement. Patients were asked to score pain from 0-10 every second hour after arrival in the coronary care unit (CCU) and also to score their maximal pain at home. A very high intensity of chest pain was observed at home (mean score 7.1). At arrival in the CCU the mean pain score already had declined to 1.8, although 51% still had chest pain. Pain score declined successively during the first 12 hours in the CCU. At 24 hours after arrival, 20% still had some chest discomfort. In one quarter of the series a score of more than 0 was observed later than 24 hours after arrival in CCU. Patients developing definite MI had, as expected, a longer duration of pain and a much higher requirement of morphine compared with those with no MI. The difference between MI and no MI patients regarding subjective assessment of the initial intensity of pain at home and in hospital was, however, surprisingly low.     

Blood viscosity in ischemic heart disease

Through a capillary viscometer we measured venous and arterial blood viscosity (BV) in 25 patients with the diagnosis of ischemic heart disease (IHD); 10 of them with unstable angor pectoris (UA) and 15 with acute myocardial infarction (MI). The control group consisted of 100 normal individuals in whom the normal values were 2.70 +/- 0.10 centipoises, where as in patients with AU the values were 4.03 +/- 1.40 centipoises and in the group with MI was 3.65 +/- 1.20 centipoises. Statistically, we correlated the BV obtained in both groups with the following parameters: coronary risk factors, cell blood count; serum glucose, cholesterol and triglycerides as well as the number of coronary arteries involved. The levels of venous and arterial BV were elevated in both groups of patients in comparison with the control group. We concluded that arterial and venous BV is elevated in patients with IHD independently of the hematocrit. This suggest the probability of some other factors such as plasmatic viscosity and platelets aggregation could play a role in the BV elevation of this group of patients.     

Transthoracic Doppler echocardiography assessment of left anterior descending artery flow in patients with previous anterior myocardial infarction.

AIM: We tested the hypothesis that shortening of diastolic pressure half time (PHT) of left anterior descending (LAD) coronary flow in patients with old reperfused anterior myocardial infarction (MI) is related to the presence of permanent myocardial damage of the reperfused area. METHODS AND RESULTS: We studied 49 patients divided into: group A: 15 patients with previous anterior MI and evidence of myocardial scar; group B: 10 patients with previous anterior MI and no evidence of myocardial scar and group C: 24 patients without anterior MI. All patients underwent coronary angiography at least 6 months after an index event and any reperfusion procedure. Group A patients had lower PHT (199 +/- 62 ms) than group C (377 +/- 103 ms, p = 0.0001) and group B (316 +/- 154 ms, p = 0.029) patients. No other LAD flow velocity parameter differed among the 3 groups. A PHT value of 265 ms discriminated patients with scarred anterior wall with a sensitivity of 79% and a specificity of 94% (0.88, p < 0.001). CONCLUSION: Shortening of the LAD flow diastolic PHT in patients with remote, reperfused anterior MI reflects scarred myocardial tissue in the anteroapical wall while patients who maintain diastolic wall thickness after an acute coronary syndrome have PHT similar to patients without anterior MI.     

Early assessment of long-term risk with continuous ST-segment monitoring among patients with unstable coronary syndromes. Results from 1-year follow-up in the TRIM study

A total of 323 patients who took part in the TRIM trial underwent an initial 24 h continuous electrocardiogram ST-segment monitoring. A ST vector magnitude (ST-VM) maximum > or = 144 microV predicted death or myocardial infarction within 1 year with a 78% specificity and a 52% sensitivity, an area under the ST-VM trend curve > or = 162 mu with a 86% specificity and a 42% sensitivity and presence of ST-VM episodes with a 70% specificity and a 68% sensitivity. Patients who had neither ST-VM episodes nor a ST-maximum > or = 144 microV had only a 4.5% incidence of death or myocardial infarction within one year as compared to 18% among those patients who met any of these criteria. ST-segment monitoring with continuous vectorcardiography is feasible for risk stratification at least up to 1 year after an episode of unstable coronary artery disease and several vectorcardiographic parameters may be used.