Role of coronary spasm for a positive noninvasive stress test result in angina pectoris patients without hemodynamically significant coronary artery disease

BACKGROUND: A positive noninvasive stress test result is often considered as a false-positive indicator of coronary artery disease (CAD) when coronary angiography reveals no hemodynamically significant CAD. METHODS: From January 2001 through December 2004, 5474 patients scheduled to undergo exercise electrocardiogram (ECG) [exercise ECG without imaging or exercise ECG with thallium-201 (201Tl) single photon emission tomography (SPECT)] or dipyridamole 201Tl tomography at our outpatient clinic because of chest oppressive sensation were included in this prospective study. Coronary angiography was performed when a noninvasive test result was positive for ischemia or when ischemic chest pain was suspected. Intracoronary methylergonovine testing was performed when spastic angina was suspected and coronary angiography showed no hemodynamically significant CAD. RESULTS: Noninvasive stress testing was positive in 113 (67%) patients with coronary spasm. Of the 53 patients who had positive exercise ECG (exercise ECG with or without imaging), ST depression was found in 50 patients and ST elevationin in 3 patients. Multivessel spasm was found in 6 (15%), 6 (15%), and 7 (21%) of the patients with a positive result on exercise ECG without imaging, exercise ECG with 201Tl SPECT, and dipyridamole 201Tl SPECT, respectively. There was no significant difference in the results of noninvasive stress testing and the number of vessels with coronary spasm (1-vessel spasm versus multivessel spasm) among these 3 noninvasive stress testing groups. CONCLUSION: Intracoronary ergonovine testing induced coronary spasm in over 50% of patients who had suspected ischemic chest pain, a positive noninvasive stress test, and no hemodynamically significant CAD.     

Significant sex differences in the correlation of electrocardiographic exercise testing and coronary arteriograms.

Two hundred fifty-one patients (195 male and 56 females) referred for evaluation of chest pain were studied by multistage submaximal stress testing and selective coronary arteriography. In men with positive exercise tests the incidence rate of true positive exercise test results--that is, positive tests associated with 75 percent of greater coronary stenosis--was 89 percent in contrast to a 33 percent incidence rate of true positive exercise test results in women. The incidence rate of false positive excercise test results--that is, positive tests associated with no coronary stenosis or less than 50 percent stenosis--was 8 percent in men in contrast to 67 percent in women. Conversely, the incidence rate of false negative exercise test results (that is, negative exercise tests associated with 75 percent or greater coronary stenosis) was higher in men (37 percent) than in women (12 percent). It is concluded that in men a positive multistage stress test is useful in predicting the presence of significant coronary artery disease although a negative stress test cannot be relied upon to rule out the presence of significant disease. In women, a positive exercise test is of little value in predicting the presence of significant coronary artery disease, whereas a negative test is quite useful in ruling out the presence of significant disease. New criteria should be developed for stress testing of women.     

Exercise Testing in the Detection of Severe Coronary Artery Disease

Summary: The clinical value of exercise testing in the detection of severe coronary artery disease remains undefined. This question was examined in 289 men and 45 women. The diagnosis of coronary artery disease could be reliably made without exercise testing in patients with angina pectoris which markedly restricted walking or which was accompanied by pathological Q waves on the ECG. Such patients usually had coronary artery disease involving two or three major vessels. Exercise testing was an aid to diagnosis in patients with a normal standard ECG and chest pain suspicious of myocardial ischaemia, either mild angina or atypical. When exercise testing resulted in both angina and ST segment depression in men, coronary artery disease was present in 38 of 41 (93%) of cases. On the other hand, three vessel disease was found in only six of 100 (6%) of men whose exercise test did not evoke angina and ST segment change. A normal exercise test in a woman with suspicious chest pain and a normal ECG was associated with normal coronary arteries in 14 of 15 (93%) of cases. It may be concluded that exercise testing is of most diagnostic value in the assessment of patients with a normal standard ECG and a differential diagnosis of mild angina pectoris and atypical chest pain.     

Exercise-induced left bundle branch block and its relation to coronary artery disease

The records of 2,584 consecutive patients who underwent both treadmill exercise testing and coronary cineangiography were reviewed to determine the relation between exercise-induced, acceleration-dependent left bundle branch block (LBBB) and the presence of coronary artery disease (CAD). Rate-dependent LBBB during exercise was identified in 28 patients (1.1%), who were categorized according to their presenting symptoms: classic angina pectoris, atypical chest pain, symptomatic cardiac arrhythmia and asymptomatic. Asymptomatic patients underwent a screening exercise test. CAD was present in 7 of 10 patients who presented with classic angina pectoris, but 12 of 13 patients presenting with atypical chest pain had normal coronary arteries. All 10 patients in whom LBBB developed at a heart rate of 125 beats/min or higher were free of CAD, whereas 9 of 18 patients in whom LBBB developed at a heart rate of less than 125 beats/min had CAD. Normal coronary arteries were present in 3 patients who presented with angina and in whom both chest pain and LBBB developed during exercise. It is concluded that patients who present with atypical chest pain in whom rate-dependent LBBB develops on the treadmill are significantly less likely to have CAD than patients who present with classic angina; the onset of LBBB at a heart rate of 125 beats/min or higher is highly correlated with the presence of normal coronary arteries, regardless of patient presentation; and patients with angina in whom both chest pain and LBBB develop during exercise may have normal coronary arteries.     

Exercise Testing in the Detection of Severe Coronary Artery Disease

Summary: The clinical value of exercise testing in the detection of severe coronary artery disease remains undefined. This question was examined in 289 men and 45 women. The diagnosis of coronary artery disease could be reliably made without exercise testing in patients with angina pectoris which markedly restricted walking or which was accompanied by pathological Q waves on the ECG. Such patients usually had coronary artery disease involving two or three major vessels.
Exercise testing was an aid to diagnosis in patients with a normal standard ECG and chest pain suspicious of myocardial ischaemia, either mild angina or atypical. When exercise testing resulted in both angina and ST segment depression in men, coronary artery disease was present in 38 of 41 (93%) of cases. On the other hand, three vessel disease was found in only six of 100 (6%) of men whose exercise test did not evoke angina and ST segment change. A normal exercise test in a woman with suspicious chest pain and a normal ECG was associated with normal coronary arteries in 14 of 15 (93%) of cases. It may be concluded that exercise testing is of most diagnostic value in the assessment of patients with a normal standard ECG and a differential diagnosis of mild angina pectoris and atypical chest pain.     

Sex differences in investigation results and treatment in subjects referred for investigation of chest pain

OBJECTIVE—To evaluate differences in investigation results and treatment between men and women referred for diagnostic treadmill exercise testing and coronary arteriography.
DESIGN—Cohort study.
SETTING—Tertiary cardiology centre.
SUBJECTS—1522 subjects referred by primary care physicians to an open access chest pain clinic for initial investigation of chest pain, of whom 485 were subsequently referred for coronary arteriography; and a similar cohort of 107 subjects referred directly by secondary care physicians for diagnostic coronary arteriography.
MAIN OUTCOME MEASURES—Rates of positive exercise tests and rates for referral for arteriography and revascularisation according to sex.
RESULTS—Overall, women were less likely to be referred for arteriography and revascularisation than men. However, men were more likely to have positive exercise tests, and for various exercise test diagnostic end points men were also more likely to have significant coronary artery disease. After taking this into account, there was no sex difference in referral rates for arteriography or revascularisation.
CONCLUSIONS—There was no evidence of a sex bias resulting in inappropriate underinvestigation or undertreatment of women. However, the positive predictive value of treadmill exercise testing is low for women and further research is needed into how best to investigate women with chest pain.


Keywords: sex differences; exercise test; chest pain     

Clinical, psychological and thallium stress studies in patients with chest pain and normal coronary arteries.

The clinical and psychological profiles of 36 consecutive patients with chest pain and normal coronary arteries (study group) were compared to those of 34 patients with chest pain and significant coronary arterial disease (control group). All 70 patients were hospitalized for chest pain at least once prior to coronary angiography. The features of a typical episode of chest pain were similar in the normal coronary arteries and coronary arterial disease groups, but the female patients with normal coronary arteries had a shorter duration of a typical episode of chest pain, and the male patients with normal coronary arteries had a lower frequency of positive effort tests. Psychological testing showed the women with normal coronary arteries to have a tendency to increased somatization, anxiety, and a lower ability to identify origin of difficulties. The patients in the normal coronary and coronary arterial disease groups had psychological profiles typical of patients with chronic somatic disease. A psychiatric interview demonstrated an increased frequency of depressive trait (score 0-2) in the normal women (0.6 +/- 0.8 vs 0, P less than 0.05), and a tendency to increased somatization, anxiety, and sleeping disorders. Increased somatization was found in the normal coronary men (1.1 +/- 0.7 vs 0.5 +/- 0.7, P less than 0.05). Twenty-five patients of the normal coronary group underwent quantitative thallium stress studies, and 13 patients (52%) had evidence of stress-induced myocardial perfusion defect. There were no differences in the clinical and psychological profiles of the patients with normal and those with pathological thallium stress tests.(ABSTRACT TRUNCATED AT 250 WORDS)     

Incremental value of clinical assessment, supine exercise electrocardiography, and biplane exercise radionuclide ventriculography in the prediction of coronary artery disease in men with chest pain

The incremental value of clinical assessment, exercise electrocardiography (ECG) and biplane radionuclide ventriculography (RVG) in the prediction of coronary artery disease (CAD) was assessed in 105 men without myocardial infarction who were undergoing coronary angiography for investigation of chest pain. Independent clinical assessment of chest pain was made prospectively by 2 physicians. Graded supine bicycle exercise testing was symptom-limited. Right anterior oblique ECG-gated first-pass RVG and left anterior oblique ECG-gated equilibrium RVG were performed at rest and exercise. Regional wall motion abnormalities were defined by agreement of 2 of 3 blinded observers. A combined strongly positive exercise ECG response was defined as greater than or equal to 2 mm ST depression or 1.0 to 1.9 mm ST depression with exercise-induced chest pain. A multivariate logistic regression model for the preexercise prediction of CAD was derived from the clinical data and selected 2 variables: chest pain class and cholesterol level. A second model assessed the incremental value of the exercise test in prediction of CAD and found 2 exercise variables that improved prediction: RVG wall motion abnormalities, and a combined strongly positive ECG response. Applying the derived predictive models, 37 of the 58 patients (64%) with preexercise probabilities of 10 to 90% crossed either below the 10% probability threshold or above the 90% threshold and 28 (48%) also moved across the 5 and 95% thresholds. Supine exercise testing with ECG and biplane RVG together, but neither test alone, effectively adds to clinical prediction of CAD. It is most useful in men with atypical chest pain and when the ECG and RVG results are concordant.     

The pacing stress test: a reexamination of the relation between coronary artery disease and pacing-induced electrocardiographic changes

Electrocardiographic (ECG) changes during graded pacing-induced tachycardia have been considered unreliable as a test for the presence of coronary artery disease (CAD) because of poor sensitivity and specificity. As a result, atrial pacing has not been widely used as an alternative to exercise testing. However, the limited value of the pacing stress test may be related to technical aspects, such as the duration of pacing and ECG monitoring. To study this problem, 22 patients undergoing coronary cineangiography underwent standard exercise stress testing and graded tachycardia induced by atrial pacing. A 12-lead ECG recorder was used for both tests. Pacing tachycardia was terminated when 85% of maximal predicted heart rate had been achieved or when significant ischemic chest pain accompanied by diagnostic ECG changes occurred. The ECG was considered positive if at least 1 mm of horizontal or downsloping ST-segment depression was present. Six patients with normal or minimally diseased coronary arteries were compared to 16 patients with significant CAD. Of the patients without significant CAD, 5 (83%) had a negative electrocardiogram during both exercise and pacing. Of 16 patients with CAD, the electrocardiogram was positive for ischemia in 10 patients (63%) during exercise, in 15 (94%) during atrial pacing and in 12 (80%) after pacing. When the presence or absence of ECG changes was compared between the exercise and the pacing tests, there was a concordance of 90% (Fisher p less than 0.0015). Two patients without significant CAD (33%) had chest pain during both exercise and pacing. Among patients with CAD, 7 (44%) had chest pain during exercise and 8 (50%) had chest pain during atrial pacing.(ABSTRACT TRUNCATED AT 250 WORDS)     

Cost-effectiveness of diagnostic strategies for patients with chest pain.

BACKGROUND: Many noninvasive tests exist to determine whether patients should undergo coronary angiography. The routine use of coronary angiography without previous noninvasive testing is typically not advocated. OBJECTIVE: To determine the cost-effectiveness of diagnostic strategies for patients with chest pain. DESIGN: Cost-effectiveness analysis. DATA SOURCES: Published data. TARGET POPULATION: Patients who present with chest pain, have no history of myocardial infarction, and are able to perform an exercise stress test. TIME HORIZON: Lifetime. PERSPECTIVE: Societal. INTERVENTIONS: No testing, exercise electrocardiography, exercise echocardiography, exercise single-photon emission computed tomography (SPECT), and coronary angiography alone. OUTCOME MEASURES: Quality-adjusted life expectancy, lifetime cost, and incremental cost-effectiveness. RESULTS OF BASE-CASE ANALYSIS: The incremental cost-effectiveness ratio of routine coronary angiography compared with exercise echocardiography was $36,400 per quality-adjusted life-year (QALY) saved for 55-year-old men with typical angina. For 55-year-old men with atypical angina, exercise echocardiography compared with exercise electrocardiography cost $41,900 per QALY saved. If adequate exercise echocardiography was not available, exercise SPECT cost $54,800 per QALY saved compared with exercise electrocardiography for these patients. For 55-year-old men with nonspecific chest pain, the incremental cost-effectiveness ratio of exercise electrocardiography compared with no testing was $57,700 per QALY saved. RESULTS OF SENSITIVITY ANALYSIS: On the basis of a probabilistic sensitivity analysis, there is a 75% chance that exercise echocardiography costs less than $50,900 per QALY saved for 55-year-old men with atypical angina. CONCLUSIONS: Exercise electrocardiography or exercise echocardiography resulted in reasonable cost-effectiveness ratios for patients at mild to moderate risk for coronary artery disease in terms of age, sex, and type of chest pain. Coronary angiography without previous noninvasive testing resulted in reasonable cost-effectiveness ratios for patients with a high pretest probability of coronary artery disease.     

高血压和非高血压冠脉造影正常患者胸痛的临床特点分析

目的 分析高血压和非高血压冠脉造影正常但临床有胸痛表现患者的特点.方法 本组共160例,高血压组71例,非高血压组89例.均因胸痛胸痛怀疑冠心病而行心电图及冠状动脉造影检查,部分病人作了运动试验,心得安试验及超声心动图指标.结果 两组相比,高血压组的胸痛多为典型的劳累型心绞痛(与非高血压组相比P<0.01),β阻滞剂为主的抗心绞痛治疗常有效;静息心电图表现为左室劳损及冠状T波,运动试验多阳性(P<0.01);左室舒张末期内径、室间隔厚度及左室后壁厚度与非高血压组有明显的差别(与非高血压组相比p均<0.05);冠状动脉迂曲、僵硬.结论(1)高血压伴心绞痛的患者中有相当一部分无造影可见的冠状动脉狭窄;(2)高血压而无冠脉狭窄病变病人的胸痛以典型的劳累型心绞痛多见,可出现冠状T波,运动试验多阳性,心室肥厚,冠脉迂曲、僵硬,易发生冠脉痉挛,以及对β阻滞剂为主的抗心绞痛治疗反应较好;(3)相对于非高血压的病人,高血压患者在发生胸痛时更需要用冠状动脉造影来鉴别其是否有真正的冠状动脉粥样硬化性心脏病.     

Assessment of Diagnostic Value of Dipyridamole Testing in Angina Pectoris

Summary: In order to assess the diagnostic value of dipyridamole (D) testing, we studied the responses of 34 patients with chest pain and 10 normal subjects. Blood pressure and 12-lead ECG were recorded during and after intravenous infusion of 0.6 mg/kg dipyridamole for 10 minutes. Coronary arteriography and maximal or symptom-limited exercise tests were performed in the 34 patients with chest pain. During infusion 13 patients presented ischemic ST changes and 5 with anginal pain only. The latter group had normal coronary arteries. Among the 13 patients with ischemic ST changes, 7 had at least two critical coronary stenoses and the remaining 6 had no coronary lesions. Dipyridamole tests showed poor sensitivity (44%) and specificity (39%) with respect to coronary arteriography. The relatively high number of positive responses in subjects with normal coronary arteries indicates that the coronary steal phenomenon is not the sole cause of “ischemic” response to the drug. Indirect indexes of myocardial oxygen consumption were higher in patients with a positive response to drug infusion than in those with a negative response; however the value of rate-pressure product at infusion end never reached that observed at ischemic threshold during exercise testing in the same patient. This suggests that neither can oxygen consumption increase be considered as entirely responsible for ischemic response to dipyridamole. In conclusion dipyridamole test cannot be proposed for predicting critical coronary stenoses.     

Long-term outcome in patients with angina-like chest pain and normal coronary angiograms

BACKGROUND: Short-term prognosis of patients with chest pain and angiographically smooth coronary arteries is good in terms of development of coronary events (fatal or nonfatal myocardial infarction, coronary death, new coronary heart disease), but long-term studies are rare. PATIENTS AND METHODS: 185 consecutive patients (mean age 54 +7.8 years, 59% male)with typical angina pectoris or atypical chest pain who underwent coronary angiography between 1980 and 1989 and had completely normal coronary arteries and left ventricular function (mean ejection fraction 68%) were followed over a period of 12.0 +/- 2.9 years. Exercise tests showed ischemia in 51 patients (ECG) and 21 patients (myocardial scintigraphy), respectively. 173 patients could be recruited for follow-up. RESULTS: One patient died from acute myocardial infarction (0.05% per year). Nine patients died potentially from cardiac causes (0.51% per year) and seven from extracardial diseases. No nonfatal myocardial infarctions were documented. Six patients developed an angiographically documented coronary heart disease with significant stenoses after a mean follow-up of 12.7 years (0.3% per year). These patients had significantly more coronary risk factors than patients without coronary heart disease (2.8 vs. 1.8; p < 0.05) but not more often pathologic findings in rest-ECG (28% vs. 36%; not significant [n.s.]) and exercise test-ing (14% vs. 32%; n.s.). Frequency and intensity of chest pain remained unchanged in 34% of the patients. Symptoms regressed in more patients with an initially negative exercise test compared to patients who had a positive exercise test (78% vs. 54%;p < 0.05). The decrease in patients taking nitrates did not differ significantly between both groups (-42% vs. -27%; n.s.). CONCLUSION: Patients suffering from angina-like chest pain with normal coronary angiograms have a good long-term prognosis which does not differ from the general population of the same age. Patients with positive stress tests will have less relief from their symptoms than patients with a negative stress test over many years.     

The predictive value of anginal chest pain as an indicator of coronary disease during exercise testing

To determine the significance of anginal chest pain during exercise testing, a series of 302 patients undergoing coronary arteriography with exercise testing was reviewed. Of the 302 patients, 85 had ischemic ECG changes and chest pain (Group I); 87 patients had ischemic ECG changes but no chest pain (Group II); 25 patients had chest pain but no ischemic ECG changes (Group III); 105 patients had neither chest pain nor ischemic ECG changes (Group IV). Coronary artery disease was present in 95 per cent of Group I, 75 per cent of Group II, 72 per cent of Group III, and 28 per cent of Group IV. Of those patients with coronary disease, multiple vessels were involved in 94 per cent of Group I, 51 per cent of Group II, 67 per cent of Group III, and 21 per cent of Group IV. The predictive value for presence and extent of coronary disease showed Group I > Groups II and III > Group IV (p < 0.025). We conclude that (1) anginal chest pain during exercise testing predicts the presence and extent of coronary disease more accurately than its absence; (2) the presence of chest pain even without an ischemic ECG response during exercise testing appears to be as predictive of coronary disease as an ischemic ECG response alone; and (3) the combination of anginal chest pain during exercise testing and an ischemic ECG response is highly predictive of multivessel coronary artery disease.     

Correlation between exercise electrocardiography test and coronary flow reserve in patients without organic coronary artery stenosis

OBJECTIVES: The exercise electrocardiography (ECG) test is frequently positive in patients without organic coronary artery stenosis. Although the reason for this false positive ST depression is not fully understood, one possibility may be related to coronary microvascular abnormality. The present study investigated the relationship between the exercise ECG test and coronary flow reserve (CFR) in patients with angiographically normal coronary arteries, but with positive ECG ST depression. METHODS: This study included 67 patients, 32 with chest pain syndrome, and 35 with vasospasm. The exercise ECG test was performed without drug administration in all patients, and the CFR was determined after diagnostic cardiac catheterization. RESULTS: Although a significant correlation was recognized between ST depression and CFR in patients with chest pain syndrome (p < 0.05), there was no correlation in patients with epicardial coronary vasospasm. CONCLUSIONS: In patients with chest pain syndrome, ST depression detected by the exercise ECG test may suggest coronary microvascular dysfunction. However, in patients with coronary vasospasm, ST depression may occur without decreased CFR, suggesting that coronary spasm or other mechanism (s) relating to ST changes are present during the exercise ECG test, and careful interpretation is needed.     

Changes in regional wall contractility induced by effort in women with normal coronary angiography --report of a clinical case]

The diagnosis of coronary artery disease in women has been thought to be more difficult than in men, owing to the lower overall prevalence of disease in women, as well as more subtle clinical presentations and unspecific changes in ST segment. The authors report a clinical case of a 61-year old woman, with low cardiovascular risk and history of atypical chest pain and a positive treadmill exercise test on the inferior leads. She did an exercise echocardiogram that revealed severe hypokinesis on the anterior wall and septum with late normalization. The patient was submitted to a coronary angiography that revealed normal arteries. An echocardiogram with hyperventilation was later performed and showed the same ischemic changes as exercise did, on the inferior leads but no regional wall motions abnormalities occurred. The patient is currently asymptomatic under calcium antagonist treatment.     

运动平板试验对青年冠状动脉粥样硬化性心脏病的诊断价值

目的评估运动平板试验对青年冠状动脉粥样硬化性心脏病（冠心病）患者的诊断意义。方法选择有典型胸痛症状的青年男、女患者各200例行运动平板试验,择期进行冠状动脉造影,对其结果进行对照分析。结果男性患者冠状动脉造影结果阳性142例中运动平板试验阳性136例,阴性6例;男性患者冠状动脉造影结果阴性58例中运动平板试验阳性10例,阴性48例。女性患者冠状动脉造影结果阳性90例中运动平板试验阳性84例,阴性6例;女性患者冠状动脉造影结果阴性110例中运动平板试验阳性56例,阴性54例。运动平板试验诊断男性青年冠心病的特异性和准确性高于女性,差异有统计学意义（82．8％vs．46．5％,P〈0．01：93．0％弧60．0％,P〈0．01）。结论运动平板试验对男性青年冠心病的诊断符合率高于女性。     

Exercise echocardiographic detection of coronary artery disease in women

The utility of exercise echocardiography for the diagnosis of coronary artery disease has been demonstrated in populations consisting largely of men with a high prevalence of disease. To determine the diagnostic value of exercise echocardiography in women, 57 women who presented with chest pain were studied with coronary cineangiography and echocardiography combined with either treadmill (n = 38) or bicycle exercise (n = 19). Significant coronary artery disease (greater than or equal to 50% reduction in luminal diameter) was present in 28 (49%) of 57 patients, including 16 (84%) of 19 who had typical angina, and 12 (32%) of 38 who had atypical chest pain. The overall sensitivity and specificity of echocardiography were both 86%. Exercise echocardiography correctly determined the presence or absence of coronary artery disease in 32 (84%) of 38 patients who had atypical chest pain and in 17 (89%) of 19 who had typical angina (p = NS). The exercise electrocardiogram (ECG) was nondiagnostic in 17 patients (30%) who had rest ST segment depression or ST depression with exercise that could also be induced by hyperventilation or changes in position. The correct diagnosis was made by echocardiography in 14 (82%) of 17 patients with a nondiagnostic exercise ECG. In conclusion, exercise echocardiography has a clinically useful level of sensitivity and specificity for the detection of coronary artery disease in women. The technique provides diagnostic information in women presenting with atypical chest pain and in those who have a nondiagnostic exercise ECG.     

Lack of evidence for alpha-adrenergic receptor-mediated mechanisms in the genesis of ischemia in syndrome X

Patients with syndrome X (typical angina pectoris, positive exercise tests [greater than or equal to 1 mm of ST-segment depression], no evidence of coronary spasm and angiographically normal coronary arteries) have a reduced coronary flow reserve due to inappropriate dilatation of small resistive vessels. To assess whether alpha-adrenergic mechanisms play a role in the genesis of ST-ischemic changes in syndrome X, 12 patients with this syndrome (2 men and 10 women, mean age 50 +/- 6 years) underwent exercise testing and 24-hour ambulatory electrocardiographic monitoring. They were done off treatment and after alpha blockade with prazosin and clonidine on 2 separate weeks. Despite treatment, all exercise tests remained positive and patients were stopped because of progressive angina pain. Compared to the off-treatment tests, exercise duration and heart rate-blood pressure product at 1 mm of ST-segment depression did not change significantly after prazosin (617 +/- 203 vs 663 +/- 203 seconds and 23,857 +/- 6,125 vs 22,098 +/- 4,816 beats/min X mm Hg, respectively) and clonidine (684 +/- 148 vs 649 +/- 80 seconds and 25,514 +/- 2,386 vs 24,567 +/- 2,001 beats/min X mm Hg, respectively). Ambulatory monitoring showed similar results regarding number of episodes of ST-segment depression greater than or equal to 0.1 mV during control and after prazosin (39 vs 38) or clonidine (26 vs 23) treatment. None of the 8 patients who also underwent provocative testing with phenylephrine had ischemic electrocardiographic changes; only 2 experienced chest pain during the test.(ABSTRACT TRUNCATED AT 250 WORDS)     

Implication of probability analysis for diagnosis of stable coronary diseases. Comparison of non-invasive diagnostic tests

A prospective collection of clinical (history), electrocardiography (ECG), exercise electrocardiography (EE), dobutamine stress echocardiography (SE) and catheterization data was performed in 551 patients with chest pain regarded as definite or probable stable angina pectoris. All patients (65% male) without prior history of myocardial infarction undergone clinical evaluation: chest pain classification according to Diamond, ECG, EE (regarded as positive on the basis of > or = 1 mm ST-depression), SE (ischemia was defined as new or worsening wall motion abnormalities using a 16-segment model) and coronary angiography (CA):CAD was defined as > or = 50% narrowing of at least one major vessel. Sensitivity and specificity of ECG, EE, SE was calculated: and results are as follows respectively: 23% and 87%, 93% and 21%, 85% and 69%. On the basis of these results with implication of probability analysis two algorithms were developed by computer program. They incorporated pretest variables: age, gender, chest pain classification, ECG and results of one or two non-invasive tests: EE and (or) SE. The sensitivity and specificity of the algorithm is 96% and 44%. CONCLUSIONS: 1. Chest pain characteristics remains an effective tool for estimating probability of CAD. 2. The diagnostic value of resting electrocardiography in stable CAD is low. 3. SE has comparably sensitivity but significantly higher specificity than EE. 4. We demonstrated that when the likelihood of CAD is high on the basis of initial evaluation, diagnostic non-invasive testing is not indicated before CA. 5. When the probability is intermediate or low, implementation of first choice test should be different in women (SE) and men (EE).