Comparison between dobutamine echocardiography and thallium-201 scintigraphy in detecting residual stenosis,ischemia, and necrosis in patients with prior myocardial infarction

Background: Following the first attempts to detect myocardial ischemia with two-dimensional echocardiography stress testing, pharmacologic stress using dobutamine infusion has become an alternative to echocardiography exercise testing for evaluation of coronary artery disease. It has been shown that stress echocardiography has a diagnostic accuracy similar to that of an exercise thallium test. Other studies, however, indicated that radionuclide myocardial perfusion imaging was more sensitive than exercise or pharmacologic stress echocardiography for detection of ischemia or jeopardized myocardium. Hypothesis: The aim of the present study was to determine the ability of dobutamine stress echocardiography in comparison with thallium-201 scintigraphy to identify multivessel disease and the presence of myocardial scar and ischemia in 60 consecutive patients who suffered a first myocardial infarction (MI). Methods: Patients were evaluated by coronary angiography and ventriculography, thallium-201 (²⁰¹Tl) tomographic scintigraphy, and dobutamine echocardiography within 3 months of a first MI. Forty-seven had Q-wave MI and 13 had non-Q-wave MI. Eleven patients were excluded from final analysis—7 because of failure to achieve target heart rate in spite of the use of atropine, and 4 because of high blood pressure following the infusion of dobutamine. Results: Dobutamine echocardiography showed an overall sensitivity of 43% for detection of coronary artery lesions of 50–74% diameter stenosis and ²⁰¹Tl scintigraphy showed a sensitivity of 71%. For detection of lesions of ≥75% diameter stenosis, dobutamine echocardiography showed a sensitivity of 52% and ²⁰¹Tl a sensitivity of 70%. Overall agreement between wall motion and myocardial perfusion for detection of necrosis and/or ischemia in the infarct area was 40.4% with a kappa coefficient of 0.09 (p = 0.13). For detection of ischemic myocardium outside the infarct zone, overall agreement was 78.6% with a kappa coefficient of 0.49 (p<0.0001). Conclusion: Dobutamine echocardiography results showed a lower sensitivity than myocardial perfusion images in predicting multivessel coronary artery disease, and there was poor agreement between both methods in identifying necrosis or ischemia.     

Abnormal left ventricular early diastolic filling during dobutamine stress Doppler echocardiography is a sensitive indicator of significant coronary artery disease

Objectives. This study was designed to assess changes in Doppler indexes of left ventricular ejection and filling in response to high dose (40 μg/kg body weight per min) dobutamine stress and their utility in detection of coronary artery disease compared with that of new wall motion abnormalities.Methods. Ten patients with a low likelihood of coronary artery disease served as a control group, and 23 patients with documented single-vessel coronary artery disease underwent baseline and peak dobutamine echocardiographic and Doppler studies.Results. In both groups dobutamine induced similar increases in heart rate and systolic blood pressure. During the test, 14 patients had new wall motion abnormalities, 13 had angina, and 7 had electrocardiographic ST segment changes. No markers of ischemia occurred in the control subjects. Dobutamine induced qualitatively similar changes from baseline to peak dobutamine stress in control subjects and patients in peak aortic velocity (46% vs. 42%, p = NS), average aortic acceleration (61% vs. 43%, p = 0.03) and systolic time-velocity integral (7% vs. 2%, p = NS). Dobutamine caused marked increases in control subjects and decreases in patients in peak early filling velocity (E) (33% vs. −22%, p < 0.0001) and average E acceleration (76% vs. −28%, p < 0.0001). The response of Doppler early filling indexes to dobutamine stress was abnormal in all patients. There was no overlap in the percent change from baseline to peak dobutamine stress between control subjects and patients for E and E acceleration.Conclusions. During dobutamine stress testing, an abnormal response of Doppler indexes of left ventricular early filling is a more sensitive marker of significant single-vessel coronary disease than are new wall motion abnormalities, and it is far superior to the response of Doppler ejection variables as a predictor of coronary artery disease.     

Assessment of thallium scintigraphy and echocardiography during dobutamine infusion for the detection of coronary artery disease

Dobutamine infusion was performed in 16 patients following cardiac catheterization, and non-invasive assessment was performed with thallium SPECT and echocardiography. Dobutamine thallium scintigraphy was abnormal in 93% of patients with significant coronary artery disease. In addition, individual epicardial vessel involvement was identified by a corresponding perfusion defect with 88% sensitivity and 93% specificity. Dobutamine echocardiography revealed segmental wall motion abnormalities in 62% of patients with significant coronary disease. However, in six patients baseline segmental wall motion abnormalities on echocardiography improved during dobutamine infusion. Dobutamine thallium SPECT is a safe and useful test for the detection and localization of coronary artery disease. Dobutamine echocardiography is less useful in screening for coronary disease, but may detect areas of abnormally functioning myocardium having retained viability. © 1993 Wiley-Liss, Inc.     

Dobutamine stress echocardiography: its role in the diagnosis of coronary artery disease.

We have assessed the usefulness of dobutamine infusion for the diagnosis of coronary artery disease by using two-dimensional echocardiography and 12-lead electrocardiogram. Dobutamine was infused at incremental doses (up to a maximum of 40 micrograms kg-1 min-1) in 52 patients with chest pain; all the patients underwent coronary angiography; significant coronary artery disease was quantitatively defined as greater than or equal to 50% diameter stenosis. Thirty-six patients were on betablockers. The test was considered positive when new regional wall motion abnormalities appeared during dobutamine infusion. No significant side effects occurred in any patient during the test. Transient wall motion abnormalities were detected in 20 of 37 patients with coronary artery disease (sensitivity = 54%); ischaemic ST segment changes were present on ECG in nine patients (sensitivity = 24%). Dobutamine stress echocardiography was negative in 12 of 15 patients with coronary artery diameter stenosis less than 50% (specificity = 80%). Exercise electrocardiography (ECG) was performed in 35 of these 52 patients. Maximum heart rate and systolic blood pressure were significantly higher during exercise than during dobutamine stress test (127 +/- 23 vs 99 +/- 24 beats min-1, P less than 0.0001; 179 +/- 25 vs 152 +/- 30 mmHg, P less than 0.0001). The exercise ECG test was positive in 12 of the 26 patients with significant coronary artery disease (sensitivity = 46%), and dobutamine stress echocardiography in 16 (sensitivity = 62%). Dobutamine stress echocardiography test is a safe and feasible diagnostic test for the noninvasive diagnosis of coronary artery disease and can be performed in patients unable to exercise.(ABSTRACT TRUNCATED AT 250 WORDS)     

Atropine augmentation in dobutamine stress echocardiography: Role and incremental value in a clinical practice setting

Objectives. This study sought to evaluate the role and incremental value of atropine in a large patient group undergoing dobutamine stress echocardiography.Background. The use of atropine to potentiate dobutamine stress is not standard practice. Although the utility of atropine has been described, data on its incremental value remain limited and do not exist for a routine clinical practice setting.Methods. Dobutamine stress echocardiography was perfomed in 1,171 patients with use of a standard protocol. Atropine (maximal dose 2.0 mg) was given to 299 patients (26%) who did not attain target heart rate. Coronary angiography was performed in 183 patients (46 received atropine), 148 of whom were found to have significant coronary artery disease (≥ 70% diameter stenosis in a major epicardial vessel, ≥50% stenosis for left main coronary artery disease). All tests were reviewed independently by experienced observers.Results. There were no major adverse events. Patients receiving atropine had a lower rest heart rate (65 vs. 74 beats/min, p < 0.0001) and more often received beta-adrenergic blocking agents (49% vs. 14%, p < 0.0001). Of 444 patients in whom stress-induced ischemia developed, 70 (16%) required atropine before ischemia became evident. Sensitivity for detection of significant coronary artery disease was 90% with dobutamine alone and 95% after the addition of atropine. In 66 patients with normal wall motion at rest, test sensitivity was 65% before and 84% after atropine was given. Atropine use did not compromise test specificity. New diagnostic information was obtained in 20 (50%) of 40 patients with angiographic coronary artery disease given atropine. Proportionately more patients with single-vessel disease required atropine before an ischemic response was observed; this effect appeared related to the higher ischemic threshold in these patients.Conclusions. Augmentation of heart rate had a modest influence on the overall diagnostic sensitivity of dobutamine stress echocardiography in our study cohort. However, it was particularly helpful in patients receiving beta-blockers and those with milder coronary disease. Despite the use of ≥1 mg of atropine in some patients, this incremental value was not achieved at the expense of safety.     

Transesophageal dobutamine stress echocardiography for evaluation of patients with coronary artery disease

Objectives. The present study was undertaken to determine the safety, feasibility and diagnostic accuracy of transesophageal dobutamine stress echocardiography for the evaluation of patients with known or suspected coronary artery disease.Background. Dobutamine stress echocardiography has proved to be a valuable method for detecting and prognosticating ischemic heart disease, In addition, it may provide accurate information about myocardial viability in patients with systolic dysfunction. However, in some patients the technique may be limited by poor myocardial imaging with the conventional transthoracic approach.Methods. Seventy-six patients (62 men, 14 women; mean age ± SD 60 ± 10 years) who underwent coronary angiography were included in the study. Transesophageal stress echocardiograms were performed after withdrawal of antianginal medications for ≥ 48 h. Dobutamine was infused at a starting dose of 2.5 μg/kg body weight per min and was increased by 5-μg/kg per min increments every 5 min to a maximum of 40 μg/kg per min. Two-dimensional views were acquired at each stage and digitized for subsequent analysis. The left ventricle was divided into 16 segments, and each segment was assigned to a major coronary artery with the use of a model of regional distribution of coronary perfusion.Results. Sixty-two of the 76 patients had angiographic evidence of coronary artery disease. New or worsening regional wall motion abnormalities developed during dobutamine infusion in 55 of these 62 patients and in none of the 14 patients with normal coronary arteries (sensitivity 89%, specificity 100%, overall accuracy 91%). Regional wall motion abnormalities in the distribution of more than one major coronary artery were seen in 3 of the 25 patients with single-vessel coronary artery disease and in 30 of the 37 patients with multivessel disease (p < 0.0001). The test was successfully completed in 73 (96%) of the 76 patients; it was discontinued in the remaining 3 patients because of intolerance to the probe. No major complications occurred in any patient. Minor complications developed in seven patients but did not affect the diagnostic accuracy of the test.Conclusions. Transesophageal dobutamine stress echocardiography is a safe, feasible and accurate method for assessing coronary artery disease. Its use should be considered in patients who have a suboptimal ultrasound window, and it provides an excellent tool for clinical investigations based on ultrasound imaging of the myocardium.     

The echo-dobutamine test for the diagnosis of myocardial ischemia. Study on 20 patients with normal kinetics at rest

We have assessed the value of dobutamine stress echocardiography for the diagnosis of myocardial ischemia in 20 consecutive patients referred for chest pain, without a previous myocardial infarction and with a normal left ventricular wall motion at rest. The test was considered positive when wall motion abnormalities appeared during dobutamine infusion (from 5 to a maximum of 40 micrograms/Kg/min). The results were compared to the % diameter stenosis (%DS) quantitatively measured on coronary arteriography. "Significant" coronary artery disease was defined as greater than or equal to 50% DS. No significant side effects occurred in any patients during the test. Transient wall motion abnormalities were detected in 8 of the 12 patients with significant coronary artery disease (sensitivity = 66%) and in 1 of the 8 patients without significant coronary artery disease (specificity = 88%). All the patients with false-negative dobutamine stress echocardiography had distal stenosis or stenosis in a collateral vessel; moreover, all the patients with true-positive dobutamine stress echocardiography had proximal (7 patients) or middle (1 patient) stenosis. The results of this study show that dobutamine stress echocardiography is a safe and feasible test for the noninvasive diagnosis of myocardial ischemia.     

A comparison of wall motion analysis and systolic left ventricular long axis function during dobutamine stress echocardiography.

AIMS: To compare long-axis function and wall motion analysis for the detection of significant coronary artery stenoses in patients with single and multivessel disease. METHODS AND RESULTS: We performed dobutamine stress echocardiography in 67 subjects, 14 with normal coronary anatomy, and 53 with significant coronary disease. A blunted increase in mean long-axis shortening of <0.25 cm was the best discriminator for coronary artery disease (sensitivity 85%, specificity 81%). Using this threshold, long axis function gave a sensitivity of 88% and specificity 89% for the detection of coronary artery disease in patients with normal resting wall motion while wall motion abnormality analysis had a sensitivity 73% and specificity 94%. Of 26 patients with a resting wall motion abnormality, 14 (54%) had multivessel disease. Long axis function detected multivessel disease in 12 of these (sensitivity 86%) compared with nine (sensitivity 64%) for wall motion analysis. CONCLUSION: Long axis function provides a promising, quantitative adjunct to wall motion analysis for the detection of coronary ischaemia using dobutamine stress echocardiography in patients with single and multivessel disease and with resting wall motion abnormalities.     

Left ventricular systolic dysfunction during exercise and dobutamine stress in patients with hypertrophic cardiomyopathy

OBJECTIVES: We sought to characterize stress-induced left ventricular systolic dysfunction in patients with hypertrophic cardiomyopathy (HCM). BACKGROUND: Myocardial ischemia and diastolic dysfunction occur in patients with HCM. We hypothesized that, in the setting of transient myocardial ischemia, left ventricular systolic dysfunction occurs during exercise and dobutamine stress. METHODS: We studied 39 patients with HCM but without obstructive symptoms at rest or coronary artery disease. A continuous ventricular function monitor equipped with cadmium telluride detectors (VEST) was used to evaluate left ventricular function during supine bicycle ergometer exercise. Dobutamine stress echocardiography (DSE) was also performed. The left ventricular ejection fraction (LVEF) and regional wall motion were determined from echocardiographic images. RESULTS: Changes in the LVEF correlated between exercise and dobutamine stress (r = 0.643, p < 0.0001). The LVEF decreased more than 5% at peak exercise in 17 of patients (group II), while the other patients had normal responses (group I). New regional wall motion abnormalities during dobutamine infusion were detected in 18 of 110 (16.4%) segments in group I and 42 of 85 (49.4%) segments in group II. Decreased or unchanged regional wall motion occurred more frequently in hypertrophied segments than in nonhypertrophied segments (p < 0.0001). There were significant inverse correlations between the LVEF responses during both stresses and the number of abnormal segments noted during dobutamine stress in all patients (VEST: p < 0.005; DSE: p < 0.0005). Signs of left ventricular obstruction were observed in 11 of 39 patients during DSE. However, there was no significant correlation between the LVEF response and the dobutamine-induced left ventricular pressure gradient. CONCLUSIONS: Exercise-induced systolic dysfunction occurred in 50% of patients with HCM. In these patients, regional wall motion abnormalities were present in hypertrophied segments.     

Dobutamine stress echocardiography in orthotopic heart transplant recipients

Objectives. This study sought to determine whether dobutamine stress echocardiography could accurately identify coronary artery disease after heart transplantation.

Background. After heart transplantation, coronary artery disease is related to either diffuse concentric intimal thickening or focal stenosis and may be underdiagnosed by coronary angiography.

Methods. We enrolled 41 patients, a mean (±SD) of 40 ± 20 months after heart transplantation, at the time of their routine control coronary angiogram. Three patients were excluded because of poor echogenicity on the angiogram and one because of ventricular premature beats. Standard echocardiographic views were acquired at baseline and at incremental dobutamine infusion levels (from 5 to a maximal dose of 40 μg/kg body weight per min at 3-min intervals). Regional wall motion score was calculated from a 16-segment model, and each segment was graded from 1 (normal) to 4 (dyskinesia). Coronary angiography was performed 24 h after dobutamine stress echocardiography, and angiograms were analyzed in blinded manner.

Results. Twenty-three (62%) of 37 patients had normal coronary angiographic findings. Dobutamine stress echocardiography showed abnormalities in only 2 of 23 patients. Fourteen patients (38%) had abnormal angiographic findings, seven of whom had stenoses >50%. Dobutamine stress echocardiography correctly identified the corresponding hypoperfused segments in these seven patients. More of interest were the other seven patients, of whom three had angiographic nonsignificant stenoses (<50%), and four had minor diffuse coronary irregularities. Dobutamine stress echocardiography showed hypokinesia in five of these seven patients despite nonsignificant lesions at coronary angiography. The respective overall sensitivity and specificity of dobutamine stress echocardiography were 86% and 91%. At follow-up, 2 of the 37 patients had an acute myocardial infarction. Both had abnormal findings on dobutamine stress echocardiography: One had normal coronary angiographic results, and one had significant coronary lesions.

Conclusions. Dobutamine stress echocardiography is a useful technique for the diagnosis of coronary artery disease after heart transplantation. These preliminary results indicate that dobutamine stress echocardiography may have a predictive value for further ischemic events in heart transplant recipients.     

Comparison of exercise stress testing with dobutamine stress echocardiography and radionuclide ventriculography for diagnosis of coronary artery disease

Dobutamine stress echocardiography, Tc-99m radionuclide ventriculography (RNVG), and exercise stress testing were performed prospectively in 63 patients with suspected coronary artery disease to compare the values of exercise testing, dobutamine stress echocardiography and RNVG in the non-invasive diagnosis of coronary artery disease. The sensitivities of dobutamine stress echocardiography and RNVG were found to be higher than that of exercise testing (93-62%, p < 0.001; 83-62%, p < 0.05). The sensitivities of dobutamine stress echocardiography and RNVG were similar (p > 0.05). There were no differences between the sensitivities of the three techniques in multiple vessel disease (p > 0.05). The specificities of dobutamine stress echocardiography and RNVG were higher than that of exercise testing (for both of the tests 86-62%, p < 0.05). The diagnostic accuracy of dobutamine stress echocardiography and RNVG were similar (p > 0.05). The results of dobutamine stress echocardiography RNVG were concordant with each other in 46 patients (76%, kappa = 65%) in sectional analysis. Dobutamine stress echocardiography and RNVG tests were comparable with each other in 85% of the 189 segments (kappa = 64%). The expected 5% decrease at peak doses of dobutamine was not detected in stress echocardiography in 25 patients and in RNVG in 26 of the patients. Dobutamine stress echocardiography and RNVG are superior to exercise testing in the diagnosis of single vessel disease and there is no significant difference between the two techniques. When the ejection fraction is considered in dobutamine stress echocardiography and RNVG, it does not make an additional contribution to the diagnosis of coronary artery disease.     

False positive dobutamine stress echocardiograms: Characterization of clinical,echocardiographic and angiographic findings

Objectives. This study was designed to characterize the clinical, echocardiographic and angiographic findings in patients who have regional wall motion abnormalities predictive of coronary artery disease on dobutamine stress echocardiograms, although coronary angiography reveals no critical stenoses.Background. The specificity of dobutamine stress echocardiography has been reported to be lower than its sensitivity; the sources of false positive findings on dobutamine stress echocardiograms have not been previously defined.Methods. Clinical and echocardiographic characteristics were retrospectively reviewed for patients who had both a dobutamine stress echocardiogram indicate of coronary artery disease on the basis of wall motion abnormalities and <50% stenoses reported on coronary angiography performed within 6 weeks of the echocardiogram. A 16-segment model was used to perform wall motion scoring. Angiograms were independently reviewed, and stenosis severity was quantified with the use of digital calipers.Results. Thirty-nine (11.4%) of 342 studies met criteria for false positive test results, which occurred predominantly in women (72%, p < 0.601). Regional wall motion abnormalities were evident more often in the posterior circulation (62%), and 65% of them were limited to the basal segments. Twelve (28%) of 43 wall motion abnormalities were associated with coronary stenoses of at least intermediate grade (lumen diameter 40.3% to 68.1%). Abnormalities confined to basal segments of the posterior circulation were unlikely to have associated coronary lesions (p = 0.03).Conclusions. False positive findings on dobutamine stress echocardiograms tend to involve small wall motion abnormalities that are frequently located in basal segments of the posterior myocardial circulation. Approximately one third of false positive results occurred in patients with intermediate-grade coronary stenoses, and these studies may reflect true inducible ischemia. Additional sources of false positive study results may include poor endocardial visualization and abnormal motion dye to tethering to the fibrous skeleton of the heart. Altered echocardiographic diagnostic criteria may be appropriate for small wall motion abnormalities confined to basal segments of the posterior circulation.     

Prevalence and relevance of a septal diastolic notch during dobutamine stress echocardiography

Background Dobutamine stress echocardiography has become an accepted simpleand inexpensive method of detecting coronary artery disease.In this pharmacological stress test, particular attention hasbeen paid to transient systolic wall motion abnormalities. Ourgroup has noted an abnormal diastolic ventricular septal motion,a ‘diastolic notch’, during dobutamine stress echocardiographythat has not been previously described. Methods and Results To find out whether this anomalous septal motion is relatedto coronary artery disease we have analysed the stress studiesof 125 patients (69 men, age 61±9 years) with chest pain,no previous myocardial infarction and no left bundle branchblock, who underwent a dobutamine stress test. Dobutamine wasinfused up to 40µ.kg.^–1min^–1in 3min stages.A positive stress test was defined as the appearance of transientasynergy. Dobutamine time was the time from the infusion ofdobutamine to the appearance of transient asynergy. The diastolicnotch time was the time at which diastolic notch was first detected.Diastolic notch was detected in 21 patients with single coronaryartery disease, 19 of whom had a severe left anterior descendingartery stenosis. Diastolic notch was present in 19 out of 27patients (70%) with single left anterior descending stenosis.Twenty-six out of 44 patients with multivessel coronary arterydisease had evidence of a diastolic notch and 20 of these 26had severe stenosis of the left anterior descending artery.Finally, all three patients with left main coronary artery diseasehad a diastolic notch while no patient with angiographicallynormal coronary arteries had this sign. In patients with a diastolicnotch and a positive dobutamine stress test, diastolic notchtime was shorter than dobutamine time (9±4min vs 11±3min,P<0·05). Conclusions In patients without previous myocardial infarction and withoutleft bundle branch block (1) the appearance of a septal diastolicnotch during dobutamine stress echocardiography is very specificfor the presence of coronary artery disease; (2) the detectionof diastolic notch is mostly related to the existence of severeleft anterior descending artery stenosis; (3) diastolic notchprecedes the development of ventricular asynergy.     

Prognostic value of pharmacologic stress echocardiography in patients with idiopathic dilated cardiomyopathy: a prospective, head-to-head comparison between dipyridamole and dobutamine test

BackgroundInotropic reserve identified by dobutamine or dipyridamole stress echocardiography is associated with a better outcome in patients with idiopathic dilated cardiomyopathy (DCM), although the relative prognostic value of each remains unsettled. The purpose of the present study was to assess the relative prognostic value of dobutamine versus dipyridamole stress echocardiography for the prediction of all-cause death in patients with idiopathic DCM.Methods and ResultsEighty-seven patients (63 were male, aged 54 ± 12 years) with DCM and an ejection fraction less than 35% underwent both dipyridamole and dobutamine stress echocardiography on different days and in a random order. In all patients, wall motion score index and ejection fraction were evaluated at baseline and peak stress. All patients were followed up for an average of 52 months. All-cause death was identified as the prognostic end point. During the follow-up, 26 all-cause deaths occurred (29.8%). On multivariate analysis, either dobutamine echocardiography (relative risk 0.299; P = .02; 95% confidence interval 0.084–0.835) or dipyridamole echocardiography (relative risk 0.161; P < .00; 95% confidence interval 0.07–0.394) added significantly to a prognostic model based on clinical and resting echocardiographic variables. Survival was 83% in patients with dobutamine and 84% in patients with dipyridamole-induced contractile reserve.ConclusionsDobutamine and dipyridamole stress echocardiography have similar feasibility and prognostic accuracy in DCM risk stratification.     

Pharmacological stress echocardiography in the diagnosis of coronary artery disease and myocardial ischaemia: a comparison between dobutamine and dipyridamole.

The objective of this study was to relate regional wall motion abnormalities assessed by dobutamine and dipyridamole stress echocardiography to quantitative measurements of coronary artery stenoses in consecutive patients referred for coronary angiography, and to compare haemodynamic effects of and complications related to the two agents. Patients underwent stress echoes on separate days in random sequence and had coronary angiography within 3 days of stress echocardiography. Echocardiograms were assessed by two investigators unaware of the patients' coronary anatomy. Coronary angiograms were also assessed quantitatively using the computer-assisted Cardiovascular Angiography Analysis System. There were 46 consecutive patients referred for coronary angiography; 28 were using beta-antagonists. Main outcome measures were sensitivity and specificity for dobutamine and dipyridamole stress echocardiography for detection of coronary artery disease (wall motion abnormalities at rest or stress) and myocardial ischaemia (stress induced new wall motion abnormalities). Sensitivity for the detection of myocardial ischaemia was found to be 57% for dobutamine and 64% for dipyridamole. Specificities were 78% and 89% respectively. Sensitivities for detection of coronary artery disease (lesion > or = 50% diameter stenosis) was 79% for dobutamine and 82% for dipyridamole; specificities were 78% and 89% respectively. These differences between the two agents are not significant. There were no severe side effects with either agent. Mean heart rate rose significantly with both tests but was higher with dobutamine; mean systolic blood pressure rose with dobutamine and fell with dipyridamole. It was concluded that dobutamine and dipyridamole stress echocardiography have similar sensitivities and specificities for detection of myocardial ischaemia and coronary artery disease although the haemodynamic effects of the two agents are different. Both are free from serious complications.     

Echocardiographic detection of coronary artery disease during dobutamine infusion.

BACKGROUND. Two-dimensional echocardiography performed during dobutamine infusion has been proposed as a potentially useful method for detecting coronary artery disease. However, the safety and diagnostic value of dobutamine stress echocardiography has not been established. METHODS AND RESULTS. In this study, echocardiograms were recorded during step-wise infusion of dobutamine to a maximum dose of 30 micrograms/kg/min in 103 patients who also underwent quantitative coronary angiography. The echocardiograms were digitally stored and displayed in a format that allowed simultaneous analysis of rest and stress images. Development of a new abnormality in regional function was used as an early end point for the dobutamine infusion. No patient had a symptomatic arrhythmia or complications from stress-induced ischemia. Significant coronary artery disease (greater than or equal to 50% diameter stenosis) was present in 35 of 55 patients who had normal echocardiograms at rest. The sensitivity and specificity of dobutamine-induced wall motion abnormalities for coronary artery disease was 89% (31 of 35) and 85% (17 of 20), respectively. The sensitivity was 81% (17 of 21) in those with one-vessel disease and 100% (14 of 14) in those with multivessel or left main disease. Forty-one of 48 patients with abnormal echocardiograms at baseline had localized rest wall motion abnormalities. Fifteen had coronary artery disease confined to regions that had abnormal rest wall motion, and 26 had disease remote from these regions. Thirteen of 15 patients (87%) without remote disease did not develop remote stress-induced abnormalities, and 21 of 26 (81%) who had remote disease developed corresponding abnormalities. CONCLUSIONS. Echocardiography combined with dobutamine infusion is a safe and accurate method for detecting coronary artery disease and for predicting the extent of disease in those who have localized rest wall motion abnormalities.     

Analysis of interinstitutional observer agreement in interpretation of dobutamine stress echocardiograms

Objectives. This study sought to determine the degree of interinstitutional agreement in the interpretation of dobutamine stress echocardiograms.Background. Dobutamine stress echocardiography involves subjective interpretation. Consistent methods for acquisition and interpretation are of critical importance for obtaining high inter-observer agreement and for facilitating communication of test results.Methods:Five experienced centers were each asked to submit 30 dobutamine stress echocardiograms (dobutamine up to 40 μg/kg body weight per min and atropine up to 1 mg) obtained in patients undergoing coronary angiography. Thus, a total of 150 dobutamine stress echocardiograms were interpreted by each center without knowledge of any other patient data. Left ventricular wall motion was assessed using a 16-segment model but was otherwise not standardized. No patient was excluded because of poor wage quality or inadequate stress level. Echocardiographic image quality was assessed using a five-point scale.Results. Angiographically significant coronary artery disease (≥50% diameter stenosis) was present in 95 patients (63%). By a majority decision (three or more centers), the sensitivity, specificity and accuracy of dobutamine echocardiography were 76%, 87% and 80%, respectively. Abnormal or normal results of stress echocardiography were agreed on by four or all five of the centers in 73% of patients (mean kappa value 037, fair agreement only). Agreement on the left anterior descending artery territory (78%) was similar to that for the combined right coronary artery/left circumflex artery territory (74%), and for specific segments the agreement ranged from 84% to 97% and was highest for the basal anterior segment and lowest for the basal inferior segment. Agreement was higher in patients with no (82%) or three-vessel coronary artery disease (100%) and lower in patients with one-or two-vessel disease (61% and 68%, respectively). Agreement on positivity or negativity of stress test results was 100% for patients with the highest image quality but only 43% for those with the lowest image quality (p = 0.003).Conclusions. The current heterogeneity in data acquisition and assessment criteria among different centers results in low inter-institutional agreement in interpretation of stress echocardiograms. Agreement is higher in patients with no or advanced coronary artery disease and substantially lower in those with limited echocardiographic image quality. To increase interinstitutional agreement, better standardization of image, acquisition and reading criteria of stress echocardiography is recommended.     

Dobutamine stress echocardiography for detection and assessment of coronary artery disease.

Stress echocardiography with dobutamine infusion for detection of coronary artery disease is a potential alternative to exercise stress testing with some theoretic advantages. Fifty patients who were not receiving cardioactive medication were prospectively studied with two-dimensional echocardiography and 12-lead electrocardiography (ECG) during incremental dobutamine infusion (5, 10, 15 and 20 micrograms/kg body weight per min, each dose for 8 min). Images were analyzed by using an 11-segment left ventricular model. All patients underwent correlative exercise ECG and coronary angiography, which revealed normal coronary arteries in 14 and significant disease (greater than or equal to 70% diameter stenosis) in 36. Peak rate-pressure product during dobutamine infusion was 18,845 +/- 4,156 versus 23,740 +/- 6,158 mm Hg/min on exercise (p less than 0.01). Interobserver concordance for wall motion analysis was good (kappa coefficient = 0.77). The use of baseline (n = 14) or reversible (n = 24) regional asynergy to define an abnormal dobutamine echocardiogram resulted in a sensitivity for detecting coronary artery disease of 78% and a specificity of 93%. Corresponding data for the dobutamine ECG were 47% and 71% and for the exercise ECG were 72% and 71%, respectively. The development of new mitral regurgitation on Doppler color flow imaging (n = 4) improved sensitivity to 81% without loss of specificity. Inducible asynergy or new mitral regurgitation was observed in 6 (50%) of 12 patients with single-, 6 (60%) of 10 with double- and 12 (86%) of 14 with triple-vessel disease. The site of transient asynergy provided additional localizing information. Exercise duration and time to diagnostic ST segment shift were shorter in patients with coronary artery disease with versus those without echocardiographic evidence of ischemia (both p less than 0.05). Side effects during dobutamine infusion were mild and short-lived. Dobutamine stress echocardiography is well tolerated, is useful for detection and assessment of coronary artery disease and is applicable to patients unable to exercise.     

Einflu? der Bildqualit?t auf die Genauigkeit der nichtinvasiven Isch?miediagnostik mit der Dobutamin-Stre?magnetresonanztomographie im Vergleich zur Dobutamin-Stre?echokardiographie

The analysis of wall motion abnormalities with dobutamine stress echocardiography is an established method for the detection of myocardial ischemia. With ultrafast magnetic resonance tomography, the application of identical stress protocols as used for echocardiography is possible. In 208 consecutive patients (147 M, 61 F) with suspected coronary artery disease, dobutamine stress echocardiography partially using harmonic imaging and dobutamine stress magnetic resonance tomography (DSMR) were performed prior to cardiac catheterization. DSMR images were acquired during short breath holds in 3 short axis-, a 4-, and a 2-chamber view using a turbo gradient echo technique. Patients were examined at rest and during a standard dobutamine-atropine scheme until submaximal heart rate was reached. Regional wall motion was assessed in a 16 segment model. Significant coronary heart disease was defined as angiographic >/=50% diameter stenosis. With DSMR, significantly more patients yielded very good (69%) or good (13%) image quality in comparison with dobutamine stress echocardiography (20% and 31%, p<0. 05). Moderate image quality occurred in 16% with MR and 41% with dobutamine stress echocardiography (p<0.05), 2% and 8% were non-diagnostic. With each technique 18 patients could not be examined (DSE: emphysema: 10, adipositas: 8, DSMR: claustrophobia: 11, adipositas: 6, contraindication: 1). Four patients did not reach target heart rate. In 107 patients, significant coronary artery disease was found. With DSMR sensitivity was 88.7% (dobutamine stress echocardiography: 74.3%; p<0.05) and specificity 85.7% (dobutamine stress echocardiography: 69.8%; p <0.05). This difference was most pronounced in the group with moderate echocardiographic image quality. High dose DSMR is superior to dobutamine stress echocardiography and can replace this technique especially in patients with moderate echocardiographic image quality.     

Abnormal contractile responses during dobutamine stress echocardiography in patients with idiopathic dilated cardiomyopathy

BACKGROUND: In chronic heart failure augmented wall stress leads to increased energy demand. Supply, however, may be reduced due to coronary vasoconstriction and endothelial dysfunction. This might lead to a mismatch between demand and supply. In the present study we further explored the effect of increased demand during dobutamine stress echocardiography. METHODS AND RESULTS: Sixteen patients with idiopathic dilated cardiomyopathy (mean age 44+/-13 years, New York Heart Association class II-III, mean left ventricular ejection fraction 0.27+/-0.10) underwent dobutamine stress echocardiography (5-40 microg/min per kg bodyweight+atropine if required). Wall motion and thickening was assessed in 16 segments using a four-point scale. Eleven patients (69%) showed regions with worsening of wall motion or a biphasic response during dobutamine infusion. Of the remaining five patients one patient did not show any wall motion changes and one patient showed a partial improvement while only in three patients wall motion improvement in the whole heart was found. CONCLUSION: A majority of patients with idiopathic dilated cardiomyopathy showed decreased wall motion during increased demand, i.e. ischemia-like myocardial contractile responses during dobutamine stress echocardiography. These findings further support the concept that an energy mismatch between demand and supply might play a pathophysiological role in idiopathic dilated cardiomyopathy.