Hyperventilation test: a noninvasive screening test for coronary vasospasm

3 patients with coronary vasospasms in different clinical situations are presented. One patient had typical Prinzmetal angina but coronary arteries without significant stenosis. One patient without typical angina pectoris showed sudden significant ST elevations on anterior and lateral ECG tracings accompanied by typical ischemic chest pain. At angiography, a 70% LAD stenosis was found without high degree lesions. One patient (aged 30 years) had a documented anterior infarction with angiographically normal coronary arteries. In all these cases coronary vasospasms were recognized as the underlying cause of the symptoms. All the patients were treated with calcium channel blockers and have been asymptomatic since. Currently available data comparing the diagnostic value of hyperventilation with other tests for coronary vasospasms, such as ergonovine or acetylcholine, are discussed. The hyperventilation test can be recommended as the first test in the work up of suspected vasospastic angina pectoris.     

White cell-reduced red cells prepared by filtration: a critical evaluation of current filters and methods for counting residual white cells

Atrial natriuretic peptide (ANP) is reported to dilate a major coronary artery in both experimental animals and humans. Spasm of a major coronary artery is the cause of variant angina pectoris and can be induced by hyperventilation. The effect of the ANP infusion on anginal attack induced by hyperventilation was studied in patients with variant angina pectoris. The study was performed in the early morning on 3 consecutive days in 11 patients with variant angina pectoris in whom the attacks were reproducibly induced by hyperventilation. On days 1 and 3 (saline solution infusion), and day 2 (ANP infusion), hyperventilation was started 14 minutes after beginning infusion of ANP (0.1 microgram/kg/min) or saline solution for 6 minutes. The attacks were induced in all 11 patients by hyperventilation on days 1 and 3. However, the attacks were not induced in any patient on day 2 of the ANP infusion. The plasma ANP level increased from 33 +/- 7 pg/ml to the peak level of 2,973 +/- 479 pg/ml (p < 0.01) at the end of the ANP infusion, and the plasma level of cyclic guanosine monophosphate (cGMP) increased from 5 +/- 1 pmol/ml to the peak level of 58 +/- 6 pmol/ml (p < 0.01) 5 minutes after the ANP infusion. The plasma levels of ANP and cGMP did not change after hyperventilation on days 1 and 3. It is concluded that the ANP infusion suppresses the attacks induced by hyperventilation in patients with variant angina pectoris, and cGMP is related to the mechanisms of suppression of the attacks.     

Long-term effect of alkaline, organic acid, or hot water washes on the microbial profile of refrigerated beef contaminated with bacterial pathogens after washing

One hundred consecutive patients (81 male and 19 female) with unstable angina pectoris undergoing coronary angiography were divided according to Braunwald's clinical classification. Seventeen (17%) patients had new onset angina (class I), 68 (68%) sub-acute angina (class II) and 15 (15%) had acute rest angina (class III). Twenty-seven (27%) patients had secondary unstable angina pectoris (class A), 49 (49%) primary unstable angina (class B) and 24 (24%) had post-infarction unstable angina (class C). ST-T wave changes on ECG were present in 54 (54%) while absent in 46 (46%) patients. On coronary angiography, 26 (26%) patients had single vessel disease, 30 (30%) double vessel disease and 39 (39%) patients had triple vessel disease. Five (5%) patients were found to have normal coronaries. Classification of patients according to Braunwald's clinical classification showed single vessel disease to be higher in class I as compared to class II (47% vs 22%; p = 0.04) and classes III (47% vs 20%; p<0.01). Single vessel disease was found to be higher in class C as compared to class B (41.7% vs 16.4; p = 0.01). Double vessel disease was higher in class B as compared to class A (40.8% vs 18.5%, p = 0.04). Triple vessel disease incidence was not found to be significantly different among different clinical classes. Morphology of coronary artery lesions was classified according to Ambrose's classification. Out of the total of 248 lesions in the whole study group, there were 68 (27.42%) concentric lesions, 55 (22.18%) eccentric type I lesions, 23 (9.27%) eccentric type II lesions, 42 (16.94%) multiple irregularity lesions and 60 (24.19%) totally occluded lesions. Concentric lesions were found to be higher in class C as compared to class B (40% vs 19.8%; p = 0.014). Statistically significant difference was not present in the distribution of other morphological type of lesions among different clinical classes. In the whole study group, intra-luminal thrombus was found to be present in 17 (17%) of patients. Distribution of intra-luminal thrombus according to Braunwald's classification showed that none of the patients in class I had intra-luminal thrombus, while 13 (19.1%) patients in class II and 4(26.7%) in class III had intra-luminal thrombus. The difference in the occurrence of intra-luminal thrombus between class I and class II (p = 0.004) and class I and class III (p = 0 .03 was found to be significant. Thus, majority of patients undergoing coronary angiography had primary sub-acute rest angina. Single vessel disease was higher in new onset angina. Patients with unstable angina pectoris and ST-T changes on ECG had higher number of lesions per patient and higher eccentric type I lesions. Intra-luminal thrombus was more frequently encountered with acute rest angina. However, the distribution of different morphological type of lesions on coronary angiography did not differ significantly in different clinical classes of unstable angina pectoris divided according to Braunwald's classification.     

Coronary obstruction secondary to direct cannulation

Four patients are reported with obstruction of the proximal left main coronary artery that developed following prosthetic replacement of the aortic valve. Angina pectoris and ventricular arrhythmias were the presenting clinical manifestations. Anterior descending coronary artery bypass was used in 3 of the patients and vein patch angioplasty in the fourth. One patient died in the hospital. The 3 survivors achieved reflief from angina and ventricular arrhythmias. One patient died from nephropathy 2 1/2 years later. Two patients remained asymptomatic 1 1/2 and 3 years later, respectively. This review emphasizes the need for prompt coronary angiography in patients experiencing angina pectoris after aortic valve replacement, and it shows that coronary revascularization can be performed with satisfactory results.     

Evaluation of rapid atrial pacing in diagnosis of coronary artery disease. Evaluation of atrial pacing test

Seventeen patients presenting with anginal-type pain were studied by bicycle exercise testing, rapid atrial pacing, and coronary angiography. Ten patients with angina and abnormal pacing tests at rates less than 180/minute were found to have significant coronary artery disease as demonstrated by coronary angiography. Seven patients with pacing-induced chest pain only at rates of 180 and above had normal coronary angiogram. This suggests that patients requiring rates of 180 or more to produce a positive atrial pacing test, following our protocol, do not usually have significant coronary artery disease though confirmation requires a larger study.     

Exercise ECG and case history in the diagnosis of latent coronary heart disease among presumably healthy middle-aged men

Previously undetected coronary heart disease (CHD) was suspected in 152 of 2014 presumably healthy males aged 40-59 yr. 63 had angina pectoris, 100 a positive exercise test and only 13 both angina and a positive exercise test. Coronary angiography was performed in 105 cases of whom 69 had a positive angiogram. A 2:1 proportion of true vs false positive diagnoses of CHD was found regardless of whether the diagnosis was suspected by the exercise test and/or the case history. Exercise test data show that CHD-suspect individuals differ only marginally from normal age counterparts irrespective of angiographic findings. However, of the 12 with a positive exercise ECG and maximal pulse greater than or equal to 2 SD below normal mean, 10 had pathologic angiograms. Of 58 with positive exercise ECGs and pathological angiograms, 43 had work performance below normal mean. By using a target pulse of 150 beats/minute 69% of the positive exercise ECGs had remained undisclosed.     

Criteria of myocardial ischemia in bicycle ergometry of patients with stenosing arteriosclerosis of the cardiac coronary arteries depending on the initial ECG at rest

The sensitivity of various criteria of the physical exercise test in revealing myocardial ischemia was studied in 2 groups of patients with ischemic heart disease: 1st group of 64 patients with normal ECG at rest, 2nd group of 96 patients with cicatricial changes in the myocardium. Selective coronography demonstrated atherosclerotic narrowing (stenosis of more than 70%) of one or more coronary arteries of the heart in all patients. During physical exercise an attack of angina pectoris without "ischemic" changes on the ECG occurred in 36.1% of patients of the 1st group and in 22.4% of patients of the 2nd group. The frequency of other clinical signs of cessation of the exercise (dyspnoea, change of arterial pressure, extrasystole and others) was three and a half times higher in patients with cicatricial changes in the myocardium. It is concluded that the frequency with which signs of myocardial ischemia are revealed during physical exercise depends not only on the pronounced character of the pathological coronary condition and the development of collateral circulation but also by the sensitivity of the separate ECG leads and the presence and localization of cicatricial changes in the myocardium.     

Value of QT dispersion in the interpretation of exercise stress test in women

BACKGROUND: Exercise testing in women is associated with a high incidence of false-positive ECG changes and should be combined with an imaging study. The QT dispersion (QTD), recorded as the difference between maximum and minimum QT intervals on a 12-lead ECG, is sensitive to myocardial ischemia and may improve the accuracy of exercise testing in women. METHODS AND RESULTS: Exercise ECGs were analyzed in 64 women who had undergone exercise ECG and coronary angiography for clinical indications: 20 patients with normal exercise stress test and nonsignificant (< or = 50% diameter narrowing of a major epicardial coronary artery) coronary artery disease (CAD) on angiography (true-negative; TN group), 20 patients with positive exercise stress tests (> or = 1 mm ST-segment depression or reversible perfusion defects) and significant CAD (true-positive; TP group), and 24 patients with positive exercise stress tests but no significant CAD (false-positive; FP group). The exercise QTD was 45+/-15 ms in TN, 80+/-23 ms in TP (P<.0001 versus TP), and 41+/-14 ms in FP (P=NS versus TN and <.0001 versus TP) groups. A stress QTD of > 60 ms had a sensitivity of 70% and specificity of 95% for the diagnosis of significant CAD compared with 55% (P<.05) and 63% (P<.01), respectively, for > or = 1 mm ST-segment depression during stress. When QTD of > 60 ms was added to ST-segment depression as a condition for positive test, the specificity increased to 100%. CONCLUSIONS: Exercise QTD is an easily measurable ECG variable that significantly increases the accuracy of exercise testing in women.     

Adenyl-cyclase activity in rat-hair-cycle

ECG and cinecoronary angiography of two patients with Prinzmetal's variant angina are reported. A pathologic study was performed on both. In one case, a transient luminal obstruction of the left circumflex coronary artery became apparent during selective coronary arteriography. Histologic examination of the corresponding coronary segment revealed a severe concentric atherosclerotic process with a normal-sized muscular layer, so that the angiographic transient occlusion might be attributed to an arterial spasm. In the second case no angiographic narrowings were demonstrated by cinecoronary angiography. Nevertheless, histologic examination revealed significant obstructive atherosclerotic narrowing in some coronary segments. It is suggested that atherosclerotic disease may be present also in cases with variant angina who have apparently normal coronary angiograms.     

The prognostic significance of angina pectoris experienced during the first month following acute myocardial infarction

BACKGROUND: Angina pectoris accompanied by transient ST-segment changes during the in-hospital phase of acute myocardial infarction (AMI) is a well established marker of subsequent cardiac death and reinfarction. HYPOTHESIS: This study was undertaken to record the prognostic significance of angina pectoris experienced during the first month following discharge from AMI. METHODS: In all, 803 patients included in the placebo arm of the Danish Verapamil Infarction Trial II were followed up for 18 months in 20 coronary care units in Denmark. The patients were randomized to placebo and were still on study treatment 1 month after discharge. Of these patients, 311 (39%) reported chest pain during the first month following discharge. RESULTS: Patients with angina pectoris had a significantly increased risk of reinfarction [hazard 1.71; 95%-confidence limit (CL): 1.09, 2.69] and increased mortality risk which, however, only reached borderline statistical significance (hazard 1.52; 95%-CL: 0.96, 2.40). When patients were subdivided according to both angina pectoris and heart failure, those with one or both of these risk markers had significantly increased mortality (p 0.03) and reinfarction (p 0.02) rates compared with patients free of both angina pectoris and heart failure. CONCLUSION: Patients with postinfarction angina pectoris have a significantly increased morbidity risk.     

1998 Annual Meeting of the Society of Orthopedics and Athletic Traumatology (GOTS)

BACKGROUND: Elevation of acute phase proteins [C-reactive protein (CRP) and serum amyloid type A (SAA)] has been demonstrated in unstable angina with an adverse clinical prognosis. HYPOTHESIS: The study was undertaken to determine the effect of angioplasty on the levels of SAA and the correlation with postangioplasty restenosis. METHODS: In a university-affiliated tertiary medical center, a prospective case study was undertaken in 55 patients who underwent successful percutaneous transluminal coronary angioplasty (PTCA) of a single coronary lesion for angina pectoris. Three groups of patients were clinically characterized according to Braunwald's classification of anginal syndrome: Group A: class III; Group B: class I; Group C: stable angina. Serum amyloid type A was measured by an ELISA method before PTCA and after 24 h, 1, and 3 months. Patients were followed clinically for 12 months. A thallium stress perfusion scan was performed 3 months after PTCA and coronary angiography was repeated in patients with an abnormal thallium perfusion scan. RESULTS: Serum amyloid type A levels > 100 micrograms/ml could identify Group A patients with a high sensitivity and specificity (r = 0.85 and 0.86, respectively). Of the patients studied, 75% increased their SAA level 24 h after angioplasty. An increase of SAA by > 100% was associated with an increased risk of restenosis, with a relative risk of 6.4 (p < 0.05). CONCLUSION: Increased levels of SAA characterize patients with unstable angina pectoris with a high specificity and sensitivity. Levels of SAA that increase > 100% 24 h after angioplasty may serve as a marker of restenosis.     

The importance of ambulatory ECG monitoring for determining the prognosis of patients with stable stenocardia]

149 patients with coronary artery disease and stable angina pectoris underwent coronary angiography and had coronary artery stenosis over 50 per cent. All the patients were also subjected to 24-h Holter monitoring at primary examination and 12-18 months after it. Typical ischemic ST changes were defined by transient horizontal or descending ST depressions > 1.0 mV (measured 80 ms after the J point) lasting at least for a minute. 75 (50.3 per cent) patients had episodes of silent myocardial ischemia. The course of the disease was assessed in follow-up period of 12-18 months. Four variants of the course were determined: cardiac events (16 patients), the disease progression (33 patients), a stable course (75 patients), clinical remission (25 patients). A significant correlation between the occurrence, the slope and duration of silent ischemia, the data of selective coronary angiography and clinical course of ischemic heart disease was established. Cardiac events occurred in 87.5% of the patients with silent myocardial ischemia who had total ischemic burden 30 minutes or more and/or ST-segments decrease 3.0 mm and more during heart rate less than 100 beat-min. The stable course was registered in patients with silent ischemia or without it with similar frequency. Clinical remission of angina pectoris in the patients with silent ischemia was observed rarely. The results of this study demonstrate that silent ischemia is an important prognostic factor.     

Complete occlusion of all three main coronary arteries, with survival dependent on two septal arteries

A 68-year-old Asian gentleman presented with limiting angina pectoris following myocardial infarction. Coronary angiography demonstrated complete occlusion of the left anterior descending artery after the first septal, the proximal right coronary artery and also the proximal part of the circumflex. The myocardial blood supply was wholly dependent on two septal arteries.     

Experiences with endoscopic surgery in treatment of carpal tunnel syndrome. Preliminary results of a prospective study

We evaluated the association between coronary spasm and hyperinsulinemia (high immunoreactive insulin, IRI) in patients with angina pectoris. The study cohort comprised 30 patients with spastic angina pectoris, 30 patients with angina pectoris showing fixed-obstructive coronary sclerosis and 30 control subjects who were matched for body mass index, age and sex. A 75-gram oral glucose test was performed, and blood sugar and IRI were serially measured concomitant with serum total cholesterol, triglyceride and HDL cholesterol. The IRI level at 60 min, the peak IRI during the test, sigma IRI and sigma IRI/sigma blood sugar were significantly higher in the patients than in the controls. Total cholesterol and LDL cholesterol levels were significantly increased in patients showing fixed-obstructive coronary sclerosis compared to controls.     

Ergonovine-echo test to assess the significance of chest pain at rest without ECG changes

The aim of this study was to assess the feasibility and diagnostic role of ergonovine maleate infusion under continuous two-dimensional echocardiographic monitoring for the identification of vasospastic myocardial ischaemia in patients with chest pain at rest not associated with diagnostic ECG changes. One hundred and twenty-eight consecutive patients, selected on the basis of absence of ischaemic ECG changes during angina at rest before or during hospitalization, were enrolled in the study. Ergonovine maleate was i.v. administered in scaled doses (from 0.025 to 0.2 mg at 10 min intervals) under echocardiographic, electrocardiographic and systemic blood pressure monitoring. Wall motion asynergies were observed in 33 patients, accompanied by typical chest pain in 24 patients and by ECG changes in 25 (ST elevation in 13 patients, ST depression in seven, T wave changes in five). All patients were able to complete the test. Non life-threatening ventricular arrhythmias were observed in four patients exclusively in association with ischaemia. In seven patients with a positive test, coronary artery spasm was documented at angiography. In 16 patients with a positive test, the vasospastic event was reproduced by a hyperventilation-echo test or a second ergonovine maleate-echo test performed within 3 days of the first examination. In none of the patients with a negative test was documentation of myocardial ischaemia due to a primary reduction in coronary blood flow. Thus, in patients who do not show ECG changes during chest pain at rest, the ergonovine maleate-echo test is feasible and safe; it permits the recognition of ischaemic episodes on the basis of wall motion abnormalities when conventional 12-lead ECG-recorded chest pain is non-diagnostic.     

Stress echocardiography in the study of the warm-up phenomenon

To date, the "warm-up" phenomenon in patients has been evaluated by ECG and symptom analysis. We investigated the warm-up phenomenon with supine bicycle stress echocardiography in patients with coronary artery disease documented by angiography and positive stress echocardiography. Sixteen coronary artery disease patients (54 +/- 9 years), who were off treatment throughout the study, were enrolled. Each of them underwent two consecutive exercise tests (25 W/2 min) with a 10-min recovery to reestablish baseline conditions. At the end of each stage of exercise and at peak exercise, when wall motion abnormalities (WMA), 1 mm ST depression and angina occurred, and at each minute, for the first 6 min of recovery, a 12-lead ECG was recorded and rate-pressure product was calculated. Time of onset and duration of 1 mm ST depression, WMA and angina, were also determined. Peak WMA, peak wall motion score index, duration of exercise and severity of angina were also evaluated. Exercise time duration and peak rate-pressure product were greater during the second than the first test (p = 0.02, p = 0.03 respectively); the second test also showed a longer delay of the onset of 1 mm ST depression and WMA (p = 0.01, p = 0.01 respectively) and higher rate--pressure product values (p = 0.04, p = 0.03 respectively). On the contrary, wall motion score index during the first and the second test was similar. Time to angina onset was longer during the second test (p = 0.03); the recovery period of ST depression and WMA was shorter during the second test (p = 0.02). In conclusion, these preliminary data show that patients tolerated the second period of ischemia better than the first, consistent with the presence of the warm-up phenomenon. However, the similarity of values of wall motion score index and WMA did not support a reduction in the ischemic area during the second test. This is in contrast with a possible modification of myocardial metabolism which typically underlies the ischemic preconditioning.     

Left main coronary artery stenosis following aortic valve replacement using a solid coronary perfusion catheter: report of two cases

We experienced two cases of iatrogenic left main coronary artery stenosis (IOCS) following double (aortic and mitral) valve replacement (DVR). The solid coronary perfusion catheter may attribute IOCS, with grave consequence. There have been no IOCS since the time we exchanged a solid catheter for a soft one. One case, she was successfully treated percutaneous transluminal coronary angioplasty (PTCA), because she developed angina pectoris about 5 years after PTCA. But she developed angina pectoris again and angiographically left main coronary was severe stenotic. So she was undergone aorto coronary bypass grafting (CABG) to the left anterior descending. The other case, he developed angina pectoris about 3 months after DVR. He was treated with PTCA. Angiographically left mine coronary artery stenosis reduced 50% from 90%. Generally the treatment of IOCS is CABG, but we performed PTCA for 2 patients. Because we thought it was very hazardous for us to perform them open heart surgery. When it is very hazardous to perform patients open heart surgery, they need to be performed PTCA.     

Quantum chemical studies of methadone

To clarify the association between chest pain and significant coronary artery disease in patients who have aortic valve disease, 76 consecutive candidates for aortic valve replacement were evaluated prospectively with use of a historical questionnaire and coronary arteriography. Of the 76 patients, 19 (25 percent) had no chest pain, 21 (28 percent) had chest pain that was not typical of angina pectoris and 36 (47 percent) had chest pain typical of anigina pectoris. In 18 of 19 patients the absence of chest pain correlated with the absence of coronary artery disease. The single patient without chest pain who had coronary artery disease had evidence of an inferior myocardial infarction in the electrocardiogram. Thus, absence of chest pain and the absence of electrocardiographic evidence of infarction predicted the absence of coronary disease in all cases. The presence of chest pain did not predict the presence of coronary artery disease, but the more typical the pain of angina pectoris the more likely were patients to have significant coronary artery disease. Of the 21 patients with atypical chest pain, 6 (29 percent) had coronary artery disease, but of the 36 patients with typical angina pectoris 23 (64 percent) had significant coronary artery disease. In addition, when patients with chest pain not typical of angina pectoris also had coronary artery disease, the diseased vessels usually supplied smaller areas of the left ventricle than when the pain was typical of angina pectoris. In 21 of 23 patients (91 percent) with typical angina pectoris and significant coronary artery disease, lesions were present in the left coronary artery. There was no systolic pressure gradient across the aortic valve that excluded the presence of coronary artery disease, although all patients with a calculated aortic valve area of less than 0.4 cm2 were free of coronary artery disease. Patients with severe left ventricular dysfunction were more likely to have normal coronary arteries.     

Do parental convict cichlids of different sizes value the same brood number equally?

OBJECTIVES: We sought to determine endothelium-dependent vasodilator function in the brachial artery of patients with microvascular angina pectoris. BACKGROUND: Previous studies suggest the presence of endothelial dysfunction of the coronary microcirculation in patients with microvascular angina pectoris. It is not known whether endothelial dysfunction in these patients is a generalized process or whether it is confined to the coronary microcirculation only. METHODS: In 11 women (mean [+/-SD] age 60.1 +/- 7.8 years) with microvascular angina (anginal pain, normal epicardial coronary arteries, positive exercise stress test), endothelium-dependent vasodilation was assessed in the brachial artery by measuring the change in brachial artery diameter in response to hyperemic flow. Results were compared with 11 age- and gender-matched patients with known three-vessel coronary artery disease and 11 age- and gender-matched healthy control subjects. In all subjects, the intima-media thickness (IMT) of the common carotid artery was also measured. RESULTS: Flow-mediated dilation (FMD) was comparable in patients with microvascular angina and coronary artery disease (1.9 +/- 2.5% vs. 3.3 +/- 3.3%, p = NS) but was significantly lower in patients with microvascular angina than in healthy control subjects (1.9 +/- 2.5% vs. 7.9 +/- 3%, p < 0.05). IMT was significantly lower in patients with microvascular angina than in those with coronary artery disease (0.64 +/- 0.08 vs. 1.0 +/- 0.28 mm, p < 0.05) and was comparable between patients with microvascular angina pectoris and healthy control subjects (0.64 +/- 0.08 vs. 0.56 +/- 0.14 mm, p = NS). IMT > or = 0.8 mm was observed in 1 of 11 patients with microvascular angina, 1 of 11 control subjects and 10 of 11 patients with coronary artery disease. CONCLUSIONS: These findings suggest that endothelial dysfunction in microvascular angina is a generalized process that also involves the peripheral conduit arteries and is similar to that observed in atherosclerotic disease. IMT could be helpful in discriminating patients with microvascular angina and atherosclerotic coronary artery disease.     

Selective correlation of amide groups to glycine alpha protons and of arginine guanidine groups to delta protons in proteins by multiple quantum spectroscopy

Study objective: We sought to determine whether electron-beam computed tomography (EBCT) could be used as a triage tool in the emergency department for patients with angina-like chest pain, no known history of coronary disease, normal or indeterminate ECG findings, and normal initial cardiac enzyme concentrations. METHODS: We conducted a prospective observational study of 105 patients admitted between December 1995 and October 1997 to the ED of a large tertiary care hospital with 70,000 annual ED visits. The study group was comprised of women aged 40 to 65 years and men aged 30 to 55 years who presented with angina-like chest pain requiring admission to the hospital or chest pain observation unit. All patients underwent EBCT of the coronary arteries, along with other cardiac testing as deemed necessary by staff physicians. RESULTS: Of the 105 patients, 100 underwent other cardiac testing during hospitalization. Evaluation included treadmill exercise testing in 58, coronary angiography in 25, radionuclide stress testing in 19, and echocardiography in 11. Results of EBCT and cardiac testing were negative for both in 53 patients (53%), positive for both in 14 (14%), positive for tomography and negative for cardiac testing in 32 (32%), and negative for tomography and positive for cardiac testing in only 1 patient. This positive test result, on a treadmill exercise test, was ruled a false positive by an independent staff cardiologist. Two other female patients with normal exercise sestamibi or coronary angiography and EBCT findings also had false-positive treadmill exercise results. The sensitivity of EBCT was 100% (95% confidence interval, 77% to 100%), with a negative predictive value of 100% (95% confidence interval, 94% to 100%). Specificity was 63% (95% confidence interval, 54% to 75%). CONCLUSION: EBCT is a rapid and efficient screening tool for patients admitted to the ED with angina-like chest pain, normal cardiac enzyme concentrations, indeterminate ECG findings, and no history of coronary artery disease. Our study suggests that patients with normal initial cardiac enzyme concentrations, normal or indeterminate ECG findings, and negative results on EBCT may be safely discharged from the ED without further testing or observation. Larger studies are required to confirm this conclusion.