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1.
To determine the clinical significance of an increased thallium-201 (Tl-201) activity in the lung and of its clearance from the lung after exercise, computer-quantitated Tl-201 lung activity was measured and compared with hemodynamic parameters at rest and during exercise in 35 patients with coronary artery disease (CAD). All patients underwent a supine bicycle ergometer exercise test and mean pulmonary artery wedge pressure (PAWP) was measured by a Swan-Ganz catheter. Coronary angiography was also performed. On computer-generated initial and 2 and a half hours delayed anterior images, regions of interest were selected over the myocardium (M) and lung (L), and the initial L/M ratio and the (initial L)/(delayed L) ratio were calculated as indices of an increased Tl-201 lung uptake and lung clearance, respectively. The initial L/M ratio and the (initial L)/(delayed L) ratio had no significant correlation with mean PAWP at rest and had a weak negative correlation with the resting ejection fraction (r = -0.57 and r = -0.58, respectively). However, both ratios showed good correlations with mean PAWP during peak exercise (r = 0.85 and r = 0.80, respectively), suggesting that they provide useful indices for assessing the severity of exercise-induced left ventricular dysfunction.  相似文献   

2.
To determine the clinical significance of increased thallium-201 activity in the lung immediately after exercise stress, the thallium-201 scans in 227 patients undergoing cardiac catheterization were reviewed. Thallium lung activity on the Initial anterior view images were graded qualitatively as follows: 0 (none) in 175 patients (77 percent); 1+ (moderate—increased activity in the lungs but less intense than that in left ventricular myocardium) in 37 patients (16 percent); and 2+ (severe—activity equal to or greater in intensity than left ventricular myocardlal activity) in 15 patients (7 percent). Increased (1+ or 2+) lung activity was related to (1) a greater number of myocardial segmental thallium defects (probability [p] < 0.05); and (2) increased severity and extent of coronary artery disease (p < 0.05). In addition, 2+ lung thallium activity was associated with: (1) a greater prevalence of prior myocardial infarctions (p < 0.01); and (2) a lower angiographic ejection fraction at rest (p < 0.05). To determine the hemodynamic changes associated with increased lung uptake of thallium-201, supine stress thallium imaging was performed during cardiac catheterization in 12 additional patients. Of these, the five patients with increased lung activity on thallium scanning had a mean pulmonary capillary wedge pressure that increased with exercise from 12 ± 1 (mean ± 1 standard deviation) to 24 ± 3 mm Hg (p < 0.05); cardiac index did not increase with stress. In contrast, seven patients without increased lung thallium activity demonstrated an increase in mean cardiac index (p < 0.05) without an associated rise in pulmonary capillary wedge pressure (at rest = 10 ± 3 mm Hg; during stress = 12 ± 2 mm Hg). In conclusion, increased pulmonary uptake during exercise thallium-201 imaging suggests the development of exercise-induced left ventricular dysfunction. Evaluation of lung activity should be added to the routine interpretation of exercise thallium-201 myocardial imaging studies.  相似文献   

3.
An increased pulmonary thallium-201 concentration has been observed in exercise stress thallium perfusion imaging in patients with coronary artery disease. To understand the cause of this lung uptake, studies were performed in experimental animals and in patients undergoing stress thallium perfusion imaging. The extraction fraction of thallium-201 by the lungs was measured in a group of eight dogs using a dual isotope technique. Basal thallium-201 extraction fraction at rest was 0.09 ± 0.009. After administration of isoproterenol, it decreased to 0.06 ± 0.02 (difference not significant). After balloon obstruction of the left atrium (which increased mean left atrial pressure and pulmonary transit time) and after administration of acetylcholine as a bolus injection (which prolonged pulmonary transit time only) it increased to 0.19 ± 0.02 (p <0.01).Lung thallium-201 activity was measured in 86 patients who had undergone cardiac catheterization and stress-redistribution myocardial perfusion imaging. The initial/final lung activity ratio was 1.41 ± 0.03 in patients with no significant coronary artery disease, 1.52 ± 0.03 (difference not significant) in patients with single vessel coronary disease, 1.60 ± 0.05 (p <0.05) in those with two vessel disease and 1.59 ± 0.05 (p <0.05) in those with triple vessel disease. Quantitation of lung activity in 30 of these patients indicated that the increased ratio in patients with multivessel coronary artery disease was due to a transient absolute increase in the thallium-201 concentration immediately after maximal exercise. The data imply that increased pulmonary concentration of thallium-201 during exercise is a consequence of left ventricular failure.  相似文献   

4.
Increased thallium lung uptake during exercise correlates with an exercise-induced elevation In left ventricular filling pressure. This finding was analyzed in 48 patients with 1-vessel left anterior descending (LAD) coronary artery disease (CAD) before and after percutaneous transiuminal coronary angioplasty. Patients were separated into 2 groups: 13 (27%) patients with Increased (group 1) and 35 patients with normal thallium lung uptake (group 2). Compared with group 2, group 1 patients had more severe LAD luminal diameter narrowing (90 ± 6% vs 81 ± 11 % [mean ± standard deviation], p <0.003); slower clearance of thallium from the LAD territory segments (half-life 13.5 ± 8.0 vs 6.5 ± 5.0 hours, p <0.007); and more abnormal thallium segments per patient by quantitative criteria (p <0.02). After angioplasty, thallium lung uptake became normal in 12 of 13 patients in whom it was previously elevated. Increased thallium lung uptake after exercise occurs in 1-vessel LAD disease, and is related to the severity of ischemia by thallium scan and the severity of stenosis by angiography. Therefore, increased thallium lung uptake identifies a subset of patients with 1-vessel CAD with a greater amount of myocardium at risk.  相似文献   

5.
Data comparing myocardial thallium-201 imaging after exercise and intravenous dipyridamole infusion in the same patients are scarce. Accordingly, this study is a segment-by-segment quantitative analysis of regional uptake and washout of thallium-201 after dipyridamole (0.56 mg/kg) and symptom-limited exercise testing in 21 patients (ages 58 +/- 9.2 years) with chest pain studied 2.5 +/- 1.0 weeks apart. Thallium-201 activity in 9 myocardial segments was measured in initial and delayed anterior and 45 degree left anterior oblique views, producing 184 pairs of segments in the distribution of 63 coronary supply regions for direct comparison. The number of segments with normal thallium-201 uptake and the number of numerically significant defects were similar with exercise and dipyridamole (76 vs 73%, 24 vs 27%, respectively, difference not significant). A slightly higher proportion of redistribution defects was found after dipyridamole infusion compared to exercise (17 vs 10%, p less than 0.05). Agreement between 87% (165 of 189) of segment pairs was found when each was classified as either normal or abnormal. Although 24 of 189 segments were discordant, agreement was observed in 92% (61 of 63) of coronary supply regions determined to be normal (41 of 41) or abnormal (20 of 22). In 15 patients who underwent cardiac catheterization, exercise and dipyridamole-thallium-201 scintigraphy detected 61% (16 of 26) vs 61% (16 of 26) of stenoses greater than 50% (difference not significant) and 100% (19 of 19) vs 100% (19 of 19) (difference not significant) normal vessels, respectively.(ABSTRACT TRUNCATED AT 250 WORDS)  相似文献   

6.
OBJECTIVES: Increased pulmonary or right ventricular 201Tl uptake during the exercise test has been used as a marker of multivessel coronary artery disease. The most useful method for assessing the severity of coronary artery disease was evaluated among conventional evaluation of single photon emission computed tomography (SPECT), measurement of lung to heart uptake ratio (L/H), and right ventricular to left ventricular uptake ratio (RV/LV) on 201Tl images during exercise testing. METHODS: Regions-of-interest (4 X 4 pixels) were placed at the lung and the heart, and L/H was defined as mean lung uptake/mean heart uptake. Correspondingly, regions-of-interest (4 X 4 pixels) were placed at the RV and the LV, and RV/LV was defined as maximum RV uptake /maximum LV uptake. L/H and RV/LV on the initial image were analyzed in 216 patients(angiographically normal coronary arteries: 89, single-vessel disease: 82, multivessel disease: 45). The diagnostic value was evaluated using the receiver operating characteristic curve. RESULTS: All methods showed significantly higher values in patients with multivessel disease than in patients with no coronary artery disease or single-vessel disease. L/H was significantly higher in patients with prior myocardial infarction and RV/LV was significantly higher in patients without infarction. The sensitivity of only conventional SPECT evaluation for multivessel coronary artery disease was low (sensitivity 53%, specificity 94%). However, addition of evaluation of L/H and RV/LV to SPECT improved the sensitivity for multivessel coronary artery disease (sensitivity 93%, specificity 49%). CONCLUSIONS: The diagnostic sensitivity for multivessel coronary artery disease was improved by adding L/H and RV/LV to conventional evaluation of exercise 201Tl SPECT. L/H and RV/LV during exercise 201Tl imaging may provide additional information regarding the severity of coronary artery disease.  相似文献   

7.
In 61 patients with single vessel coronary artery disease (70 percent or greater obstruction of luminal diameter in only one vessel) and no previous myocardial infarction, the sites of ischemic changes on 12 lead exercise electrocardiography and on thallium-201 myocardial perfusion scanning were related to the obstructed coronary artery. The site of exercise-induced S-T segment depression did not identify which coronary artery was obstructed. In the 37 patients with left anterior descending coronary artery disease S-T depression was most often seen in the inferior leads and leads V4 to V6, and in the 18 patients with right coronary artery disease and in the 6 patients with left circumflex artery disease S-T depression was most often seen in leads V5 and V6. Although S-T segment elevation was uncommon in most leads, it occurred in lead V1 or aVL, or both, in 51 percent of the patients with left anterior descending coronary artery disease. A reversible anterior defect on exercise thallium scanning correlated with left anterior descending coronary artery disease (probability [p] < 0.0001) and a reversible inferior thallium defect correlated with right coronary or left circumflex artery disease (p < 0.0001).In patients with single vessel disease, the site of S-T segment depression does not identify the obstructed coronary artery; S-T segment elevation in lead V1 or aVL, or both, identifies left anterior descending coronary artery disease; and the site of reversible perfusion defect on thallium scanning identifies the site of myocardial ischemia and the obstructed coronary artery.  相似文献   

8.
First pass radionuclide angiocardiography and thallium-201 myocardial perfusion imaging were performed at rest and during exercise in 48 patients with chest pain: 39 with angiographically documented coronary artery disease and 9 with normal coronary arteries. Maximal graded upright bicycle exercise was used for both studies to assure identical exercise conditions. All nine patients without coronary artery disease had normal exercise thallium images, normal exercise regional wall motion and at least a 5 percent absolute increase in left ventricular ejection fraction during exercise (normal exercise left ventricular reserve). Ischemic S-T segment depression was demonstrated in 17 (44 percent) of the 39 patients with coronary artery disease. Findings on the two exercise tests were concordant in all cases. New or augmented thallium perfusion defects were detected in 24 (62 percent) of the 39 patients, whereas abnormal exercise left ventricular reserve was present in 33 (85 percent) (p <0.05). There was a close concordance between exercise-induced perfusion defects and regional wall motion abnormalities. The magnitude of change in ejection fraction from rest to exercise was significantly greater in patients with an abnormal exercise thallium study than in those with a normal study (−8 ± 2 percent versus −1 ± 1 percent, p <0.05). Both radionuclide studies were abnormal In 21 (54 percent) of the 39 patients, whereas both were normal only in 3 patients, all of whom had single vessel disease. Abnormal exercise left ventricular reserve was present in 12 patients with normal exercise thallium studies.  相似文献   

9.
To evaluate the accuracy of exercise two-dimensional echocardiography for the recognition of coronary artery disease, 53 patients (46 men and 7 women, age range 35 to 69 years) without either previous myocardial infarction or resting wall motion abnormalities, were studied. According to coronary angiography 26 had normal coronary arteries, 14 had one-vessel, seven had two-vessel, and six had three-vessel disease. After withdrawal of any therapy, all patients underwent a single exercise stress test with a stress table during which cine-loop digitized echocardiography was acquired and 74 MBq of thallium-201 (TI-201) were injected. Echocardiographic images were evaluated at rest and at peak exercise. Three-view planar scintigraphic images were collected immediately after exercise and 4 hours later. For the overall recognition of coronary artery disease, exercise electrocardiography had 77.8% sensitivity and 65.4% specificity; myocardial scintigraphy had 100% sensitivity and 92.3% specificity; and exercise echocardiography had 92.6% sensitivity and 96.2% specificity (both NS versus myocardial scintigraphy). Global accuracy was 71.7% for exercise electrocardiography, 94.3% for stress echocardiography, and 96.2% for myocardial scintigraphy. For the classification of the individual involved coronary arteries, the sensitivity of myocardial scintigraphy was 84.8% and that of exercise echocardiography was 63% (p less than 0.01); the related specificities were 98% and 98.2% respectively (NS). It may be concluded that exercise echocardiography is highly accurate for the recognition of coronary artery disease, whereas it appears less sensitive in the identification of the involved vessels, particularly in patients with multivessel disease.  相似文献   

10.
While exercise thallium imaging has improved sensitivity and specificity for detection of coronary artery disease (CAD), its predictive value for morbid cardiac events is unclear. Of 532 consecutive patients who underwent exercise thallium imaging, follow-up was complete in 515 (97%) after an average of 36 months (range 31 to 48). Two hundred six patients had an abnormal exercise thallium response and 309 had a normal response. Twenty morbid cardiac events occurred (13 deaths and 7 acute myocardial infarctions [AMI]). Of the 13 patients who died, 12 had abnormal thallium results. Overall, 5.8% of the patients with abnormal thallium results died, in contrast to 0.3% of patients with normal results. Of the 7 patients who had a nonfatal AMI, 3 had abnormal exercise thallium results. Moreover, similar proportions of patients (1.4% and 1.3%) with normal and abnormal exercise thallium results had nonfatal AMI. Presence or absence of pathologic Q waves and inclusion of exercise electrocardiographic results did not significantly alter the results. Thus, although a normal exercise thallium response significantly reduces the likelihood of cardiovascular death, its predictive value for nonfatal AMI is limited. Moreover, the relatively low event rate for patients with a positive exercise thallium response further limits its prognostic value.  相似文献   

11.
12.
13.
In order to assess the prognostic significance of normal exercisethallium-210 myocardial scintigraphy in patients with documentedcoronary artery disease, we studied the incidence of cardiacdeath and non-fatal myocardial infarction in 69 symptomaticpatients without prior Q wave myocardial infarction, who demonstratedone or more significant coronary lesions (stenosis 70%) on anangiogram performed within 3 months of scintigraphy (Group 1).These patients were compared to a second group of 136 patientswith an abnormal exercise scintigram, defined by the presenceof reversible defect(s) and angiographically proven coronaryartery disease (Group 2), and to a third group of 102 patientswith normal exercise scintigraphy without significant coronarylesions (stenosis 30%) or with normal coronary angiography (Group3). In contrast to coronary lesions observed in Group 2, patientsin Group I presented more frequently with single- vessel disease(83% vs 35%, P>0·0001) and with more distal lesions(55% vs 23%, P>0·0001). Over a mean follow-up periodof 8·6 years, one fatal and eight non-fatal cases ofmyocardial infarction were observed in Group 1. The majorityof patients in Group 1 were treated medically: only 24 (35%)underwent myocardial revascularization, usually by coronaryangioplasty. There was no significant difference in the incidenceof combined major cardiac events (cardiac death, non-fatal myocardialinfarction) in patients with normal exercise scintigraphy, withor without documented coronary artery disease (Groups 1 and3), while the incidence was higher in Group 2. However, whilethe mortality remained very low in Group 1, the incidence ofnon-fatal myocardial infraction was not different from thatof Group 2, where most patients underwent revascularizationprocedures. In conclusion, patients with coronary artery disease and a normalexercise thallium-201 myocardial scintigram usually have mildcoronary lesions (single-vessel disease, distal location) andgood long-term prognosis, with a low incidence of cardiac death.  相似文献   

14.
PURPOSE: The aim of this study was to (1) determine whether nonimaging variables add to the diagnostic information available from exercise thallium-201 images for the detection of multivessel coronary artery disease; and (2) to develop a model based on the exercise thallium-201 stress test to predict the presence of multivessel disease. PATIENTS AND METHODS: The study populations included 383 patients referred to the University of Virginia and 325 patients referred to the Massachusetts General Hospital for evaluation of chest pain. All patients underwent both cardiac catheterization and exercise thallium-201 stress testing between 1978 and 1981. RESULTS: In the University of Virginia cohort, at each level of thallium-201 abnormality (no defects, one defect, more than one defect), ST depression and patient age added significantly in the detection of multivessel disease. Logistic regression analysis using data from these patients identified three independent predictors of multivessel disease: initial thallium-201 defects, ST depression, and age. A model was developed to predict multivessel disease based on these variables. As might be expected, the risk of multivessel disease predicted by the model was similar to that actually observed in the University of Virginia population. More importantly, however, the model was accurate in predicting the occurrence of multivessel disease in the unrelated population studied at the Massachusetts General Hospital. CONCLUSION: It is, therefore, concluded that (1) nonimaging variables (age and exercise-induced ST depression) add independent information to thallium-201 imaging data in the detection of multivessel disease; and (2) a model has been developed based on the exercise thallium-201 stress test that can accurately predict the probability of multivessel disease in other populations.  相似文献   

15.
Objectives.This study assessed the incremental prognostic value of exercise thallium-201 myocardial perfusion single-photon emission computed tomography (SPECT) performed ≥5 years after coronary artery bypass surgery.Background.Thallium-201 scintigraphy has shown significant prognostic value in a variety of populations with suspected and known coronary artery disease. However, its value in patients with previous bypass surgery remains unknown.Methods.We studied 294 patients who were prospectively followed up. Cox proportional hazards models for prediction of “hard” events (cardiac death and nonfatal infarctions) were constructed, with variables considered for inclusion in hierarchic order: clinical and exercise data first, followed by scintigraphic information.Results.Mean (± SD) follow-up duration after scintigraphy was 31 ± 11 months. There were 20 cardiac deaths and 21 monfatal acute myocardial infarctions. Twenty-nine patients had late (>60) days after thallium-201 SPECT) revascularization procedures or underwent repeat bypass surgery or percutaneous transluminal angioplasty. Shortness of breath and peak exercise heart rate were the most important clinical predictors of hard events. Two scintigraphic variables added significant prognostic information to the clinical model: the thallium-201 summed reversibility score (summation of segmental differences between stress and redistribution scores) and the presence of increased lung uptake of the radiotracer. The global chi-square statistic for this model was twice as high as that for the clinical/exercise model alone (49.7 vs. 24.2). When a second multivariate Cox model was build adding “soft” events (i.e., late revascularization procedures) as outcomes of interest, the summed reversibility score was selected as an independent scintigraphic predictor of events. The global chi-square statistic for this model was 50.7, three times as high as that for the clinical/exercise model alone.Conclusions.After evaluation of treadmill and exercise data, thallium-201 myocardial perfusion SPECT provided incremental prognostic information in patients late after bypass.  相似文献   

16.
The thallium washout was analyzed in 40 patients with angiographically documented CAD, using circumferential time-activity profiles of the initial and four-hour delayed images. A net washout pattern (fewer counts in delayed images than initial images) was observed in the distribution of normal and diseased vessels. A negative washout (wash-in) (a net increase in counts in the four-hour delayed images) was observed only in the presence of diseased vessels, even if the initial scans were normal. Quantitative analysis of thallium kinetics was shown to be important in rest images, and should be performed even if the initial images appear normal.  相似文献   

17.
To determine the usefulness of exercise cardiokymography (CKG) compared to thallium-201 perfusion scanning in the diagnosis of coronary artery disease (CAD), 179 patients with a mean age of 54 +/- 10 years (73% men) were studied. Previously documented CAD was present in 73 patients (41%); 13 (7%) were asymptomatic and 93 (53%) had chest pain syndrome. Exercise stress testing, CKG, and thallium-201 perfusion scanning were independently correlated with coronary angiographic data. Treadmill exercise stress test alone without CKG had a sensitivity of 68% and specificity of 62%. CKG showed a sensitivity of 76% and a specificity of 90%, and easily interpreted cardiokymograms were obtained in 78% of patients studied. Thallium-201 scans had a sensitivity of 79% and a specificity of 88%. However, when the CKG and treadmill exercise test results were concordant (both positive or both negative), the CKG exercise test had a sensitivity of 87% and specificity of 100%. Thus, when the CKG and exercise test results are concordant, the sensitivity and specificity are equal to or better than thallium-201 perfusion scanning for the prediction of CAD. Since CKG is an inexpensive and noninvasive test, its adjunctive use with routine exercise stress testing may be of great value.  相似文献   

18.
Although coronary artery disease (CAD) may be asymptomatic, it is the most common cause of death in elderly patients in the U.S. This study examined the prognosis of 449 patients with a mean age of 65 years using exercise thallium-201 imaging. At a follow-up of 25 months, 45 patients underwent coronary artery revascularization, 8 died of cardiac causes and 10 had nonfatal acute myocardial infarctions (AMIs). Thus the total of patients with "hard" events was 18. The events included 12 of 276 patients with atypical or non-anginal symptoms versus 6 of 128 with typical angina (p = not significant); 7 of 51 patients (14%) with Q-wave AMI versus 11 of 353 (3%) without Q-wave AMI (p less than 0.001); 1 of 183 patients (1%) with normal versus 17 of 221 (8%) with abnormal exercise thallium-201 images (p less than 0.002); 10 of 76 patients (13%) with multi vessel thallium-201 abnormality vs 8 of 328 (2%) with no or 1-vessel thallium-201 abnormality (p less than 0.001) and 10 of 96 patients (10%) with greater than or equal to 3 abnormal segments by thallium-201 imaging (total segments = 9) versus 8 of 308 patients with no or less than 3 abnormal segments (p less than 0.001). The number of segments with thallium-201 defects was 1 +/- 2 patients without and 3 +/- 2 in patients with hard events (p less than 0.002).(ABSTRACT TRUNCATED AT 250 WORDS)  相似文献   

19.
The purpose of the present study was to evaluate the clinical significance of myocardial scintigraphy with nitrogen-13 (N-13) glutamate as a marker of myocardial metabolism. Within 2 weeks after cardiac catheterization, 25 patients with single vessel left anterior descending coronary artery disease underwent thallium-201 imaging (5 min and 3 h after injection) and N-13 glutamate scintigraphy (10 min after injection). Radionuclide studies were performed in the 30 degrees left anterior oblique projection after symptom-limited bicycle exercise, and regional tracer uptake was quantified by computer-assisted placement of regions of interest within the regions of myocardial activity. Poststenotic tracer uptake in the perfusion bed of the left anterior descending coronary artery (septum) was then normalized to the tracer uptake in the nondiseased left circumflex territory (posterolateral segments = 100%). In 14 patients with a history of previous myocardial infarction (Subgroup A), deficient poststenotic N-13 uptake correlated closely with thallium-201 uptake in both initial (r = 0.82, p less than 0.001) and redistribution (r = 0.74, p less than 0.01) scintigrams. By contrast, in 11 patients with no previous myocardial infarction and normal left ventricular function at rest (Subgroup B), initial uptake of both tracers was inverse: poststenotic N-13 glutamate uptake increased with decreasing thallium-201 uptake during exercise-induced ischemia (r = -0.64, p less than 0.05) and was closely correlated with the percent thallium-201 redistribution (r = 0.74, p less than 0.01). Thus, augmented accumulation of N-13 glutamate in reversibly ischemic (that is, viable) myocardium, and decreased uptake in myocardial scar tissue suggest the clinical usefulness of this metabolic tracer in the differentiation between viable (metabolically active) and irreversibly damaged myocardium.  相似文献   

20.
In many patients with valvular aortic stenosis (AS), management decisions may be possible without invasive studies if coexistent coronary artery disease (CAD) can be ruled out noninvasively. The use of thallium-201 single-photon emission computed tomography to the exclusion of CAD was studied in 44 patients aged 41 to 78 years with AS. In addition to cardiac catheterization and selective coronary angiography, patients underwent a cardiac ultrasound study and thallium-201 myocardial perfusion imaging at rest and after bicycle ergometer exercise. Two thirds of the patients had critical AS (valve area index less than or equal to 0.5 cm2/m2) but none had left ventricular systolic dysfunction. Twenty-one patients had angiographically significant CAD (greater than or equal to 50% diameter stenosis in greater than or equal to 1 coronary artery), whereas 23 had either a fully normal angiogram (n = 17) or mild (less than 50%) stenoses (n = 6). Each patient with significant CAD had an abnormal thallium-201 tomogram, either a strictly segmental perfusion defect (n = 19), or a patchy nonsegmental abnormality (n = 2); however, 10 of 23 patients free of significant CAD had similar results. Thus, the sensitivity and specificity of an abnormal scintigram were 100 and 57%, respectively. If only segmental perfusion defects typical of CAD had been considered abnormal, then the sensitivity of the test would have been 90% and the specificity 70%. Patients with false abnormal scintigrams had more severe AS and more angiographically nonsignificant CAD than those with true normal findings.(ABSTRACT TRUNCATED AT 250 WORDS)  相似文献   

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