aVR T波形态在评估急性冠状动脉综合征三支病变患者左心功能中的意义

目的 研究急性冠状动脉综合征(ACS)三支病变患者心电图aVR导联T波形态预测左心功能变化的意义.方法 160名冠状动脉造影明确的ACS三支病变患者按照入院心电图aVR导联T波形态分为T波直立组(72例)和T波倒置组(88例),比较两组一般资料、左心功能、冠状动脉病变及临床结局情况.结果 与T波倒置组比较,T波直立组左...     

Identification of anatomically extensive coronary artery disease by the exercise ECG ST segment/heart rate slope

To assess the ability of the ST segment/heart rate (ST/HR) slope to identify three-vessel coronary disease and the relationship between the ST/HR slope and the anatomic extent of disease as determined by the Gensini and Duke jeopardy scores, the exercise ECGs of 128 patients with stable angina were compared with findings at coronary cineangiography. A ST/HR slope greater than or equal to 6 microV/beat/min identified three-vessel coronary disease with a sensitivity of 93% compared with sensitivities of only 50% for early positive standard test responses (p less than 0.001) and 66% for markedly positive standard test responses (p less than 0.01). The negative predictive value of this ST/HR slope partition for three-vessel disease was 94%. Patients with ST/HR slopes greater than or equal to 6 who did not have three-vessel disease had anatomically more extensive obstruction than did patients with lower test values (mean Gensini score 43 +/- 5 vs 22 +/- 3, p less than 0.002 and mean jeopardy score 4.8 +/- 0.4 vs 3.0 +/- 0.3, p less than 0.01). Test performance of the calculated ST/HR slope exceeded that of a simplified index derived by dividing the total change in ST segment depression by the total change in heart rate. These findings demonstrate that a ST/HR slope greater than or equal to 6 is highly sensitive for the identification of three-vessel coronary disease and also identifies patients with anatomically severe obstruction. A ST/HR slope less than 6 makes three-vessel coronary disease or otherwise anatomically extensive coronary obstruction unlikely.     

New coronary artery disease index based on exercise-induced QRS changes

Exercise-induced changes in Q, R, and S wave amplitudes have been reported to detect coronary artery disease but with low specificity, low sensitivity, or both; it was hypothesized that their incorporation into a composite index (Athens QRS score) might improve specificity and sensitivity. For this purpose 246 patients were analyzed retrospectively and 160 prospectively. All patients underwent maximal exercise testing with a standard Bruce protocol and coronary arteriography as part of the diagnostic evaluation for possible or definite coronary artery disease. The Athens QRS score was decreased as the number of obstructed coronary arteries increased (normal coronary arteries = 7.85 +/- 5.23 mm, one-vessel disease = 5.2 +/- 5.3 mm, two-vessel disease = -0.85 +/- 5.4 mm, three-vessel disease = -3.5 +/- 5.8 mm; p less than 0.0001); the score was unrelated to exercise-induced ST segment depression, and negative (less than 0) scores were always associated with coronary artery disease. An Athens QRS score of 5 mm predicted coronary artery disease with sensitivity ranging from 75% to 86% and a specificity ranging from 73% to 79%, values higher than those of the Q wave (75% and 50%, respectively), R wave (65% and 55%), and S wave (70% and 10%) and of the ST segment depression (62% and 70%). It is concluded that exercise-induced changes in the QRS complex provide a useful index not only for the diagnosis but also for the assessment of severity of coronary artery disease.     

Evaluation of the exercise test in patients with angiographically documented coronary artery disease

100 male patients with at least 75% obstruction of one or more coronary arteries were subjected to submaximal exercise tests. Among the 73 subjects who had positive tests, 92% of those with one-vessel obstruction had an ST depression of 1 mm, none having more than 2 mm; by contrast, 44% of those with three-vessel disease had an ST depression of more than 2 mm and only 27% on ST depression of 1 mm. Left-ventricular end-diastolic pressure exceeded 15 mm Hg in 86% of the patients who had an ST depression of more than 2 mm but only in 33% of those with a depression of 1 mm; impaired contractility was found in 81% of the former and in 36% of the latter. 92% of those with one-vessel obstruction were able to perform work of 75 and 100 W/min while only 25% of those with three-vessel disease were able to perform the same amount of work. The peak exercise heart rate and systolic blood pressure also decreased with the increase in the number of affected vessels.     

Post-myocardial infarction exercise testing. Non-Q wave versus Q wave correlation with coronary angiography and long-term prognosis

BACKGROUND. The presence or absence of baseline diagnostic Q waves has been believed to compromise the accuracy of standard exercise electrocardiography in identifying severe coronary artery disease (three-vessel and/or left main disease); therefore, a retrospective analysis was performed using a personal computer data base of exercise test responses and cardiac catheterization results to evaluate this premise, and follow-up was performed to observe how Q waves and/or severe coronary disease impacted on survival. METHODS AND RESULTS. Two hundred fifty-three male patients who had survived a myocardial infarction were studied. Patients on digitalis, those with left bundle branch block or left ventricular hypertrophy on their baseline electrocardiogram, those with previous revascularization procedures, and those with significant valvular or congenital heart disease were excluded. All patients performed either a low-level predischarge or a sign/symptom limited exercise test and underwent diagnostic coronary angiography within 32 days of each test (range, 0-90 days). Long-term follow-up on patients was performed for an average of 45 months (+/- 17 months). Group NQMI comprised 103 post-myocardial infarction patients lacking Q waves at the time of exercise testing and group QMI comprised 150 patients who developed Q waves with their myocardial infarction. The cut points of greater than or equal to 1 mm (chi 2 = 14.39, p less than 0.001) and greater than or equal to 2 mm (chi 2 = 26.11, p less than 0.001) of exercise-induced ST segment depression were reliable markers of severe coronary disease in Q wave infarct survivors. This was also true for non-Q wave infarct survivors as greater than or equal to 1 mm (chi 2 = 6.02, p = 0.01) and greater than or equal to 2 mm (chi 2 = 4.37, p = 0.04) of ST segment depression were reliable markers of severe coronary disease. Receiver operating characteristic curve analysis revealed that exercise-induced ST segment depression had discriminating power for the identification of severe coronary artery disease in both the Q wave myocardial infarction patients (area = 0.735, z = 4.47, p less than 0.001) and the non-Q wave infarct patients (area = 0.700, z = 3.20, p less than 0.001). After 4.4 years of cumulative follow-up, patients with severe coronary disease had an infarct-free survival rate of 72% (95%, CI, 50.0-86.0%), whereas those without severe disease had an 86% (95% CI, 76.5-91.5%) infarct-free survival rate (Cox chi 2 = 4.00, p = 0.045). Non-Q wave patients had an infarct-free survival rate of 81% (95% CI, 66.0-89.5%), whereas those with Q waves had an infarct-free survival rate of 85% (95% CI, 73.9-91.3%) (Cox chi 2 = 0.0005, p = NS). CONCLUSIONS. The presence or absence of diagnostic Q waves has no significant effect on the ability of the exercise electrocardiogram to identify severe coronary artery disease in survivors of myocardial infarction. Long-term infarct-free survival of patients with myocardial infarction is more related to the presence of severe coronary disease rather than if they suffered a non-Q wave or Q wave infarction.     

Correlation between the ST/heart rate slope and the severity of coronary disease in inferior infarcts. A new criterion of positivity of the ergometric test

We reviewed a group of 80 patients who had bicycle exercise stress testing and cardiac catheterization: 60 patients with known coronary artery disease (CAD) had a remote myocardial infarction, anterior, inferior, Q and no Q wave (post MI), 20 patients evaluated for suspected CAD resulted to have normal coronary arteries or lesions less than 50%. Patients were divided into three groups according to the extent of CAD. Group I with anatomically or functionally high risk CAD: left main (LM) stenosis greater than or equal to 50%, 3 vessels CAD greater than or equal to 70%, proximal left anterior descending stenosis (PLAD) greater than or equal to 90% with another vessel CAD; group II with one or two vessels CAD greater than or equal to 70%; group III with no or insignificant CAD. Linear regression analysis of the heart rate (HR)--related change in ST segment depression (ST/HR slope) was compared with six conventional electrocardiographic exercise test criteria to evaluate whether ST/HR slope can identify with improved accuracy group I. When all 80 patients are assessed together, ST/HR slope greater than or equal to 60 mm/beat/min 10(3) compared with standard electrocardiographic criteria failed to discriminate significantly between high-risk CAD (group I) and less extensive (group II) or insignificant CAD (group III). When only Q wave inferior post MI are considered, ST/HR slope greater than or equal to 60 mm/beat/min. 10(3) compared with ST segment depression greater than or equal to 1 mm identifies group I with 90% +/- 4 versus 75% +/- 6 overall predictive accuracy (p less than 0.01).(ABSTRACT TRUNCATED AT 250 WORDS)     

Effects of atrial pacing on QT dispersion in patients with coronary artery disease without angina pectoris and ST segment depression.

The aim of this study was to investigate QT dispersion during atrial pacing in patients with coronary artery disease (CAD) without clinical ischemia, such as angina pectoris and ST segment depression. Thirteen patients with normal coronary arteries and 42 patients with CAD (12 with single-vessel, 16 with two-vessel and 14 with three-vessel disease) having no angina pectoris or ST segment depression during atrial pacing with maximum rate of 120/minute were enrolled in the study. Twelve-lead surface ECGs were recorded at 100 mm/second paper speed before pacing, at maximum pacing rate, and during the recovery period for measurement of QT interval parameters. Corrected QTd (QTcd) increased from 43.4 +/- 8.1 to 49.3 +/- 9.5 ms (p < 0.05) in the control group, from 46.1 +/- 8.1 to 74.3 +/- 7.7 ms (p < 0.0001) in the single-vessel disease group, from 48.5 +/- 10.4 to 93.8 +/- 22.1 ms in the two-vessel disease group (p < 0.0001), and from 49.7 +/- 13.6 to 128.5 +/- 31 ms (p < 0.0001) in the three-vessel disease group at peak atrial pacing period. A positive correlation was found between the severity of CAD and QTcd (r = 0.49, p < 0.0001). It was found that pacing-induced QTc dispersion identifies coronary disease extent, even when there is no ST depression or T wave inversion during pacing.     

Noninvasive assessment of left ventricular performance following transluminal coronary angioplasty

We studied 36 patients with successful transluminal coronary angioplasty (group 1) noninvasively using exercise electrocardiography, exercise T1-201 myocardial scintigraphy and equilibrium radionuclide ventriculography before and 3-5 days after the procedure. Six patients who underwent aortocoronary-bypass surgery (group 2) and 10 patients with stable angina pectoris (group 3) served as controls. All patients had arteriographically documented coronary artery disease at least in one major coronary vessel (stenosis greater than or equal to 70%). In group 1, average coronary stenosis was 81.1 +/- 8.4% before dilatation and 44 +/- 13.7% after the procedure (P less than 0.001). Ischemia score in the exercise electrocardiography decreased from 2.4 +/- 2.7 before dilatation to 0.4 +/- 0.8 after the procedure (P less than 0.001). Myocardial perfusion in computerized T1-201 myocardial scintigraphy 5-10 min after exercise expressed as vitality index (the ratio of T1-201 uptake in the ischemic region to the region of maximal uptake in the same image analyzed carefully in the same view in 2 studies) increased from 72.9 +/- 8.4% before dilatation to 79.9 +/- 11.7% after the procedure (P less than 0.001). Ejection fraction at rest increased from 47.2 +/- 9.2% to 51.0 +/- 9.7% (P less than 0.001) and during exercise from 39.9 +/- 10.5% to 49.4 +/- 10.9% (P less than 0.001) before and after the procedure. In group 2, noninvasive studies showed a tendency to improvement after surgery. In group 3 no significant changes were noted. We conclude that transluminal coronary angioplasty improves both coronary perfusion to ischemic areas supplied by critical coronary artery stenoses and left ventricular function, especially during exercise, if luminal diameter is dilated by greater than 20%.     

The treadmill exercise score revisited: coronary arteriographic and thallium perfusion correlates.

The treadmill exercise score has been used to stratify patients into low-, moderate-, and high-risk groups. This score is derived from ST segment depression, angina, and exercise duration. To determine the coronary arteriographic and exercise thallium perfusion correlates of the score, we examined the extent of coronary artery disease and exercise single photon emission computed thallium-201 results in 834 patients for whom cardiac catheterization data were available. Of those, 174 had no coronary artery disease, 195 had one-vessel, 246 had two-vessel, and 219 had three-vessel disease. Based on the treadmill exercise score, 369 were in the low-risk, 384 in the moderate-risk, and 81 in the high-risk group. The extent of coronary artery disease was 2.1 +/- 1 diseased vessels in the high-risk, 1.7 +/- 1 in the moderate, and 1.4 +/- 1.1 in the low-risk group (p < 0.01). The extent of the thallium abnormality (maximum number of abnormal segments 120/patient) was 10 +/- 6 in the high-risk, 7 +/- 6 in the moderate, and 6 +/- 5 in the low-risk group (p < 0.05). Based on the extent of coronary artery disease and results of thallium imaging, patients were reclassified into three groups: group 1 had three-vessel disease and/or > or = 10 abnormal segments (n = 387), group 3 had no coronary artery disease or one-vessel disease and less than five abnormal segments (n = 212), and the remaining patients were in group 2 (n = 235).(ABSTRACT TRUNCATED AT 250 WORDS)     

Dopamine: its potential for inducing ischemic left ventricular dysfunction

As an agent potentially capable of inducing ischemia in patients with coronary artery disease, dopamine administered intravenously was evaluated as a pharmacologic stress agent by supine radionuclide angiography, and the results were compared with ergometer exercise. In a preliminary group of 11 subjects (4 normal subjects and 7 patients with coronary disease), dopamine alone was administered in increments of 2.5 micrograms/kg per min to a maximum of 15 micrograms/kg per min. There were significant differences between exercise and dopamine in maximal stress heart rates, 129.3 +/- 30.0 versus 88.0 +/- 35.8 beats/min (p less than 0.05) in normal subjects and 118.9 +/- 21.1 versus 87.6 +/- 22.6 beats/min (p less than 0.05) in patients with coronary disease, as well as in maximal stress rate-pressure products, 213.3 +/- 51.4 versus 155.0 +/- 52.5 mm Hg/min X 10(2) (p less than 0.02) in normal subjects and 216.0 +/- 45.6 versus 161.0 +/- 48.6 mm Hg/min X 10(2) (p less than 0.003) in patients with coronary disease. As a result, in these patients the ejection fraction response was significantly different: -3.3 +/- 4.5% with exercise versus + 6.3 +/- 4.6% with dopamine (p less than 0.05). In a second group of 41 subjects (9 normal subjects and 32 patients with coronary disease), atropine (0.6 mg) was administered intravenously before and after every second dopamine dose increment. This produced statistically similar maximal stress heart rates as compared with exercise in all subjects, rate-pressure products in normal subjects and slightly higher values with dopamine in patients with coronary disease: 200.3 +/- 47.2 versus 183.1 +/- 43.0 (p less than 0.05).(ABSTRACT TRUNCATED AT 250 WORDS)     

R wave amplitude changes during stress testing. Comparison with ST segment depression and angiographic correlation

One-hundred and seven exercise stress tests and coronary angiograms were reviewed retrospectively, in order to evaluate the usefulness of R wave amplitude changes (ΔR) during exercise compared with ST segment depression in the screening of patients with coronary artery disease (CAD).We also attempted to correlate ΔR with the severity of CAD as expressed by coronary arteriography and left ventriculography.Thirty-six patients showed no coronary artery narrowing (0-V); the remaining 71 patients with stenosis of 70% of at least one of the major coronary arteries were divided into three groups.Sixteen patients had single vessel disease (1-V); five (31%) in this group showed abnormal left ventricular wall motion. Thirty-one patients had two-vessel disease (2-V); 22 (71%) of the 31 demonstrated abnormal left ventricular wall motion. Twenty-four patients had three-vessel disease (3-V); 20 (83%) of the 24 showed abnormal left ventricular wall motion.We considered ΔR values ≥ 0 and ST segment depression ≥ 1 mm. significant for diagnosis of CAD.The sensitivity of the ΔR method in predicting CAD was superior to the method based upon ST segment depression; however, the latter was significantly (P < .02) more specific than the former. The predictive accuracy of these two criteria was similar.We found ΔR values ≥ 0 more frequently in the 2-V and 3-V groups as compared with the 1-V group. Patients of the 2-V and 3-V groups had a significantly higher incidence of abnormal left ventricular wall motion (P < .01, P < .0002, respectively) in comparison with 1-V patients. Thus, ΔR values ≥ 0 during exercise stress testing are very likely related to left ventricular impairment.Even though the accuracy of the ΔR method was greater in more severe CAD, it seems to be offset by a concomitant decrease in specificity.     

Dobutamine stress echocardiography: initial experience of a Canadian centre.

OBJECTIVE: To investigate the diagnostic accuracy, electrocardiogram and hemodynamic effects and safety of dobutamine stress echocardiography. SUBJECTS: Sixty-one patients with suspected coronary artery disease. All patients underwent coronary arteriography. MAIN RESULTS: The sensitivity of dobutamine stress echocardiography in diagnosis of coronary artery disease in the whole group was 91%. In patients with left anterior descending it was 97%; right 85%; circumflex 76%; three vessel 100%; two vessel 95%; single vessel 77%. Specificity, positive predictive value and accuracy of dobutamine stress echocardiography in diagnosis of coronary disease (whole group) was 57, 94 and 87%, respectively. ST depression of more than 1 mm occurred in 11 patients, ST elevation of more than 1 mm in three patients, T wave inversion in one and T normalization in nine. Significant differences of the effects of beta-blockers were noted on the peak effects of dobutamine as follows: heart rate increase of 46 +/- 22 versus 20 +/- 13 beats/min (P less than 0.0001); systolic pressure increase of 4 +/- 26 versus 22 +/- 19 mmHg (P less than 0.01); diastolic pressure decrease of 18 +/- 16 versus 10 +/- 12 mmHg (P less than 0.03) for patients without or with beta-blockers, respectively. Unifocal ventricular premature beats were noted in 10 patients, atrial premature beats in five and ventricular couplets in one. Angina occurred in 11 patients. Atypical chest pain occurred in seven patients, tingling in 11 and nausea in four. Thirty-six patients were totally asymptomatic. CONCLUSIONS: In this population with high prevalence (85%) of coronary artery disease, dobutamine stress echocardiography had high sensitivity and positive predictive value for coronary disease detection particularly in patients with left anterior descending or three vessel disease. The specificity and accuracy were not as good, but this may reflect the small number of normal patients. Dobutamine was well tolerated and conveniently administered.     

Diagnostic value of amplitude variations of the Q wave during computerized stress electrocardiogram

Variations in the amplitude of the Q wave in lead CM5 during computerised exercise stress testing were studied in 220 patients and compared with the results of coronary angiography. The average amplitude of the Q wave increases during exercise in athletes (n = 30) from 3 +/- 2.75 mm to 4.72 +/- 2.35 mm (p less than 0.01), and in subjects without coronary artery disease (n = 49) from 0.92 +/- 1.05 mm to 1.75 +/- 1.62 mm (p less than 0.01). The Q wave did not vary significantly during exercise in patients with coronary disease but without previous infarction (n = 88) (0.70 +/- 0.91 mm to 0.62 +/- 0.85 mm). The amplitude of the Q wave did tend to decrease in patients with previous myocardial infarction (n = 83) from 1.96 +/- 2.05 mm to 1.35 +/- 1.26 mm (p less than 0.05). It is therefore possible to define a new diagnostic criterion of coronary disease: "the exercise stress test is said to be positive (delta q+) when the Q wave tends to decrease or remains stable during exercise, and negative (delta q-) when the Q wave amplitude increases during exercise". This criterion was tested in 49 normal and 83 coronary patients without infarction. The sensitivity (Se) was 79 p. 100 and the specificity (Sp) 65 p. 100, so correctly classifying 74 p. 100 of patients.(ABSTRACT TRUNCATED AT 250 WORDS)     

Variations in the amplitude of the Q wave at V5 during computerized exercise test. Value in the diagnosis of coronary insufficiency

The aim of this study was to evaluate the diagnostic value of changes in Q wave amplitude in the V5 chest lead in coronary artery disease, especially for the detection of significant (greater than or equal to 75% narrowing) left interior descending disease. The stress tests of 227 patients were reviewed and confronted with the results of coronary angiography in 93 patients with angiographically normal arteries, and 134 patients with left anterior descending disease of the latter, 37 had single vessel disease, 38 had double vessel disease and 59, triple vessel disease. The average values of the Q wave amplitude in V5 at the peak of effort were 0.97 +/- 1.04 mm in the control group; 0.53 +/- 0.65 mm (p less than 0.01) in the group with single vessel disease; 0.46 +/- 0.66 mm (p less than 0.01) in the group with double vessel disease and 0.64 +/- 0.9 mm (p = 0.04) in the group with triple vessel disease. The mean variations of the amplitude of the Q wave in lead V5 on effort in the same group of patients were: +0.55 +/- 0.73 mm (p less than 0.001); + 0.11 +/- 0.66 mm (NS); + 0.02 +/- 0.5 mm (NS) and + 0.05 +/- 0.53 mm (NS), respectively. The Q wave in lead V5 was generally deeper on effort in the control group and the average variation in its amplitude was statistically significant only in this group. In the coronary patients, the Q wave in lead V5 was generally smaller and its amplitude did not change significantly on effort.(ABSTRACT TRUNCATED AT 250 WORDS)     

Changes in amplitude of the R wave in V5 during a computerized exercise test: value in the diagnosis of coronary insufficiency

In order to determine the real value of the amplitude variations of the R wave V5 during a stress test, in the recognition of coronary insufficiency, the stress tests of 227 patients were reviewed and compared to the results of coronary angiography. This permitted to find 93 patients with healthy coronaries and 134 patients presenting an involvement of the anterior inter-ventricular artery (AIVA); 37 have a one-vessel disease, 38 have a two-vessel disease, 59 a tri-vessel disease. Quantitative analysis of the modifications of the R wave in V5 during stress, finds mean values of amplitude variations of 1.46 +/- 2.65 mm (p less than 10(-7)) in the reference group; + 1.36 +/- 3.03 mm (p less than 0.01) in patients with a one-vessel disease; +/- 2.02 +/- 2.73 mm (p less than 10(-5)) in patients with two-vessel disease; +/- 1.77 +/- 2.82 mm (p less than 10(-6)) in patients with three-vessel disease. Mean variations are not significantly different from one group to the other and do not permit to individualize a specific evolutive profile in favor of a coronary disease. Considering the absence of alterations or the increase of the amplitude of R in V5 during stress as a pathological response to a coronary insufficiency.(ABSTRACT TRUNCATED AT 250 WORDS)     

Fractional diastolic and systolic pressure in the ascending aorta are related to the extent of coronary artery disease

BACKGROUND: Ascending aortic fractional pulse pressure and fractional systolic pressure (FSP) were demonstrated to differentiate patients with and without coronary artery disease. However, no study so far has analyzed the relationship between FSP and fractional diastolic pressure (FDP) and the extent of coronary artery disease. Therefore, we investigated the relationship between ascending aortic FSP and FDP and the extent of coronary atherosclerosis in unselected patients with angiographically confirmed coronary artery disease. METHODS: The study group consisted of 445 patients (350 men and 95 women, mean age 58.5 +/- 9.7 years) with angiographically confirmed coronary artery disease and ejection fraction > 55%. Invasive ascending aortic blood pressure during catheterization and conventional sphygmomanometer measurements were taken. RESULTS: Pulse pressure (PP), FSP, and FDP derived from intraaortic measurements differentiated patients with one-, two-, and three-vessel coronary artery disease (PP, 62.8 +/- 15.8 v 64.8 +/- 17.9 v 71.7 +/- 19.1 [P < .0001]; FSP, 1.45 +/- 0.09 v 1.46 +/- 0.10 v 1.51 +/- 0.12 [P < .0001]; FDP 0.77 +/- 0.05 v 0.77 +/- 0.05 v 0.75 +/-0.06 [P < .0001]). After multivariate stepwise adjustment, the odds ratio (OR) and confidence interval (CI) of having three-vessel disease was as follows: PP per 10 mm Hg, OR = 1.15, 95% CI = 1.01 to 1.30; FSP per 0.1, OR = 1.28, 95% CI = 1.03 to 1.60; and FDP per 0.1, OR = 0.61, 95% CI = 0.39 to 0.95. None of the brachial pressure indices was independently related to the extent of coronary atherosclerosis. CONCLUSIONS: Pulse pressure (PP), FSP, and FDP of the ascending aorta are related to the risk of three-vessel disease in patients with coronary artery disease and preserved left ventricular function.     

Effect of age on left ventricular function during exercise in patients with coronary artery disease

The purpose of this study was to assess the effect of age on left ventricular performance during exercise in 79 patients with coronary artery disease (greater than or equal to 50% narrowing of one or more major coronary arteries). Fifty patients under the age of 60 years (group I) and 29 patients 60 years or older (group II) were studied. Radionuclide angiograms were obtained at rest and during symptom-limited upright bicycle exercise. The history of hypertension, angina or Q wave myocardial infarction was similar in both groups. Multivessel coronary artery disease was present in 30 patients (60%) in group I and in 19 patients (66%) in group II (p = not significant). There were no significant differences between the two groups in the hemodynamic variables (at rest or during exercise) of left ventricular ejection fraction, end-diastolic volume, end-systolic volume and cardiac index. Exercise tolerance was higher in group I than in group II (7.8 +/- 0.4 versus 5.7 +/- 0.4 minutes, p = 0.009), although the exercise heart rate and rate-pressure product were not significantly different between the groups. There was poor correlation between age and ejection fraction, end-diastolic volume and end-systolic volume at rest and during exercise. Abnormal left ventricular function at rest or an abnormal response to exercise was noted in 42 patients (84%) in group I and in 25 patients (86%) in group II (p = not significant). Thus, in patients with coronary artery disease, age does not influence left ventricular function at rest or response to exercise. Older patients with coronary artery disease show changes in left ventricular function similar to those in younger patients with corresponding severity of coronary artery disease.     

Clinical significance of simple heart rate-adjusted ST segment depression in supine leg exercise in the diagnosis of coronary artery disease

To evaluate the clinical significance of simple heart rate-adjusted ST segment depression (delta ST/delta HR) in the diagnosis of coronary artery disease, 42 patients with stable exertional angina underwent supine leg exercise testing and cardiac catheterization. During exercise, heart rate, a multilead electrocardiogram, and pulmonary artery wedge pressure were recorded. The sensitivity and accuracy of the delta ST/delta HR criteria (greater than or equal to 3.0 microV/beat/min) were significantly greater than the conventional analysis of ST segment depression criteria (greater than or equal to 0.2 mV) for detecting three-vessel coronary artery disease at a matched specificity of 72% (100% versus 46%, 81% versus 64%, p less than 0.01). A significant linear correlation was found between maximum pulmonary artery wedge pressure increments during exercise (delta PAWP) or Gensini score and the delta ST/delta HR (delta PAWP: r = 0.51, p less than 0.001; Gensini score: r = 0.47, p less than 0.001). There were no statistically significant differences in the delta PAWP or Gensini score between patients with three-vessel disease who had delta ST/delta HR greater than or equal to 3.0 microV/beat/min and those with one- or two-vessel disease who had delta ST/delta HR greater than or equal to 3.0 microV/beat/min (delta PAWP: 18.1 +/- 2.0 versus 21.9 +/- 3.3, p = NS; Gensini score: 68.5 +/- 6.6 versus 66.3 +/- 11.3, p = NS). These findings demonstrate that delta ST/delta HR is more useful than a conventional analysis of ST segment depression for identifying not only anatomically severe coronary artery disease but also functionally severe coronary artery disease.     

ST depression in ECG at entry indicates severe coronary lesions and large benefits of an early invasive treatment strategy in unstable coronary artery disease; the FRISC II ECG substudy. The Fast Revascularisation during InStability in Coronary artery disease.

BACKGROUND: In unstable coronary artery disease, ST-segment depression indicates a poor prognosis. We evaluated whether the effect of early revascularization and the extent of coronary lesions were related to ST-segment and T wave changes on admission. METHODS AND RESULTS: 2457 patients with unstable coronary artery disease were randomized to an early invasive strategy with coronary angiography/revascularization within 7 days or to a non-invasive strategy with coronary procedures only when symptoms or severe ischaemia recurred. ST depression was present in 1114 (45.5%) patients. In the invasive group, 45% of the patients with ST depression had three-vessel disease or left main stenosis compared with 22% if no ST-segment depression was present, PP=0.004 while mortality was changed from 5.8 to 3.3%, P=0.050. In patients without ST-segment depression the corresponding rates concerning death/myocardial infarction were 10.4 and 8.9, and for mortality 2.0 and 1.2% (non-significant). CONCLUSIONS: In unstable coronary artery disease, ST-segment depression is associated with a 100% increase in the occurrence of three-vessel/left main disease and to an increased risk of subsequent cardiac events. In these patients an early invasive strategy substantially decreases death/myocardial infarction.     

Significance of exercise induced ST elevation in patient without a history of previous myocardial infarct

Between 1980 and 1995, we observed twenty-five patients (22 males, 3 females) at the mean age of 50.6 +/- 13 years, without previous myocardial infarction who presented exercise induced ST elevation on a bicycle stress test. METHODS: Significant ST elevation was defined as a > or = 1 mm change present in > or = 1 lead measured 0.08 sec after the J point and in 3 consecutive beats. All patients have undergone coronary angiography in the days following the exercise test. RESULTS: Most of patients (56%) presented a history of typical angina that was either purely exertional (8 pts) or also occurred at rest (6 pts). Others (36%) had non typical angina or no angina (8%); 78% of pts were smokers. Sixteen patients (group I) had ST elevation during exercise (exercise duration: 7.6 +/- 4 min; peak heart rate: 135.5 +/- 29 batt/min; ST = 3.5 +/- 1.5 mm) and nine (group II) during the recovery phase (exercise duration 16.3 +/- 1.6 min; p < 0.05; peak heart rate 168 +/- 22 batt/min; p < 0.05; ST: 5.8 +/- 3 mm; p < 0.05). In group I, 1 patient had no vessel disease, 12 had one vessel disease, 3 had multivessel disease with 6 cases of hypersevere coronary stenose (> 90%). In group II, 4 patients had normal coronary arteries, there was one vessel coronary artery disease in 4 patients and multivessel in one subject, without hypersevere coronary stenosis. Correlation between anatomic location of stenosis and electrocardiographic ST elevation was excellent, particularly in case of single vessel disease (100%). All patients underwent one or more new exercise tests after therapeutic intervention (surgery n = 3; angioplasty n = 7; medical treatment n = 15), only 2 patients had persistent exercise induced ST elevation. During follow-up (5 +/- 3 years), 3 patients died (2 cardiac deaths) and 3 had recurrent angina controlled by new treatment. CONCLUSION: Exercise-induced ST elevation is a rare phenomenon in patients without prior myocardial infarction. When occurring purely during exercise, coronary lesions are frequent and often servere, in the other hand ST elevation of the recovery phase is frequently associate with normal arteries or less severe lesions. In most cases, revascularisation or medical therapy can abolish clinical and electrocardiographic abnormalities.