Dobutamine stress echocardiography: Detection of coronary artery disease in patients with dilated cardiomyopathy

Objectives. This study attempted to determine the safety and accuracy of dobutamine stress echocardiograpby for detection of coronary artery disease in patients with dilated cardiomyopathy.Background. Detection of regional wall motion abnormalities at rest does not reliably distinguish ischemic front nonischemic cardiomyopathy. Previous studies have shown that dobutamine stress echocardiography safely and accurately identifies coronary artery disease in patients without dilated cardiomyopathy.Methods. Seventy patients with dilated cardiomyopathy under-went dobutamine stress echocardiography. Echocardiograms were obtained at baseline and at low (5 to 10 μg/kg body weight per min) and peak doses of dobutamine. Rest and stress left ventricular wall motion scores were derived from analysis of regional wall motion. Fifty-four subjects underwent coronary angiography.Results. Dobutamine infusion was terminated after achievement of the target heart rate or maximal protocol dose in 49 patients (70%), ischemia in 12 (17%), arrhythmia in 4 (6%) and side efects in 5 (7%). No patient had prolonged ischemia or sustained arrhythmia. Of those with angiographic studies, 40 had significant coronary artery disease (≥50% diameter stenosis). Use of the change in global wall motion score index from low to peak dose resulted in a sensitivity of 83% for dobutamine stress echocardiography and a specificity of 71% for detection of coronary artery disease. Sensitivity for detection of triple-,double-and single-vessel disease was 100%, 83% and 69%, respectively.Conclusions. Dobutamine stress echocardiography safely provides diagnostic information in patients with dilated cardiomyopathy. This technique has high sensitivity for multivessel coronary artery disease but only moderate specificity.     

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.     

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 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.     

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.     

Angiographic documented coronary arterial spasm in absence of critical coronary artery stenoses in a patient with variant angina episodes during exercise and dobutamine stress echocardiography

Dobutamine stress echocardiography is widely performed as a useful diagnostic tool in patients with known or suspected coronary artery disease. Dobutamine induced myocardial ischaemia is frequently associated with ST segment depression. ST segment elevation is uncommon and is almost always associated with prior myocardial infarction or transient total coronary occlusion. Dobutamine induced ST segment elevation in absence of significant coronary artery disease is a rare condition and is supposed to be a consequence of severe coronary artery spasm. The case of a 58 year old man with variant angina episodes at rest, during exercise test, and dobutamine stress echocardiography is reported, in whom coronary spasm without significant coronary artery stenoses was documented angiographically.


Keywords: coronary spasm; variant angina; Prinzmetal angina; dobutamine stress echocardiography; exercise test     

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.     

Early dobutamine echocardiography for the assessment of coronary stenosis after first Q-wave myocardial infarction

We assessed the accuracy of early dobutamine stress echocardiography to detect infarct-related coronary artery and multivessel disease in patients with first Q wave myocardial infarction after withdrawal of cardioactive drugs. Dobutamine-atropine echocardiography was performed in 91 consecutive patients (mean age 59+/-6 years) 7+/-4 days after myocardial infarction. Dobutamine was infused at incremental doses of 5, 10, 20, 30 to 40 microg/kg/min each one dose for 3 min. Peak heart rate was 134+/-17 bpm. All patients underwent coronary angiography before discharge. Sensitivity, specificity and accuracy of ischemic and biphasic response to detect residual stenosis of infarct-related coronary artery were 70, 92 and 73%, respectively. The sensitivity, specificity and accuracy of ischemic or biphasic response were similar in the vascular territories of left anterior descending (74, 86 and 75%, respectively), right (67, 100 and 70%, respectively) and circumflex coronary arteries (64, 100, and 69%, respectively). Sensitivity, specificity and accuracy of heterozonal wall motion abnormalities for multivessel coronary artery disease were 64, 82 and 76%, respectively. Dobutamine stress echocardiography is sensitive and specific in detecting residual coronary stenosis and multivessel disease in patients with first Q-wave myocardial infarction. The test is safe even without pharmacological protection.     

Dipyridamole-dobutamine echocardiography: A novel test for the detection of milder forms of coronary artery disease

Objectives. This study was designed to assess the clinical, hemodynamic and diagnostic effects of the addition of dobutamine to dipyridamole echocardiography.Background. Pharmacologic stress echocardiography with either dipyridamole or dobutamine has gained acceptance because of its safety, feasibility, diagnostic accuracy and prognostic power. The main limitation of the two tests is a less than ideal sensitivity in some patient subsets, such as those with limited coronary artery disease. We hypothesized that two pharmacologic stresses might act synergistically in the induction of ischemia by combining the mechanisms of inappropriate coronary vasodilation (with dipyridamole) and an increase in myocardial oxygen consumption (with dobutamine).Methods. One hundred fifty patients (mean [±SD] age 51 ± 11 years) referred for stress echocardiography were initially studied by dipyridamole-dobutamine echocardiography. The test was stopped during the dipyridamole step in 95 patients for achievement of a predetermined end point (obvious dyssynergy induced by lower or higher dipyridamole dose), and dipyridamoledobutamine tests were performed in 55 patients (negative dipyridamole echocardiographic test). In the same 150 patients the dobutamine echocardiographic test (up to 40 μg/kg body weight per min) was performed on a separate day.Results. Significant coronary artery disease (>50% diameter stenosis of at least one major coronary vessel by quantitative coronary arteriography) was present in 131 patients (one vessel in 115; two vessels in 10, three vessels in 6), with normal coronary arteriography in 19. The feasibility of the dipyridamoledobutamine test was 96%. Self-limiting side effects occurred in 5% of patients. The peak rate-pressure product was lowest during the dipyridamole test (132 ± 30) and was comparable during the dobutamine (186 ± 59) and dipyridamole-dobutamine tests (179 ± 45, p = NS vs. dobutamine; p < 0.01 vs. dipyridamole). Sensitivity was 71% for dipyridamole, 75% for dobutamine and 92% for dipyridamole-dobutamine echocardiography (dipyridamole vs. dipyridamole-dobutamine, p < 0.01; dobutamine vs. dipyridamole-dobutamine, p < 0.01; dipyridamole vs. dobutamine, p = NS), whereas specificity was 89% for dipyridamole, 79% for dobutamine and 89% for dipyridamole-dobutamine echocardiography (p = NS for all).Conclusions. Routine dobutamine addition to dipyridamole stress testing is clinically useful and well tolerated. It expands the spectrum of the disease detectable by pharmacologic stress echocardiography and allows documentation of milder forms of coronary artery disease that can be missed by conventional dipyridamole or dobutamine stress echocardiography.     

Echocardiography during infusion of dobutamine for identification of reversible dyfunction in patients with chronic coronary artery disease

Objectives. The aim of this study was to test whether the contractile response of akinetic myocardium to low dose dobutamine is useful for detecting myocardial viability in patients with coronary artery diseases and persistent left ventricular dysfunction.Background. In some patients with chronic coronary artery of left ventricular wall motion can be reversed by successful coronary artery bypass surgery. Thus, identification of potentially reversible dysfunction has important therapeutic and prognostic implications. Echocardiography during infusion of low dose dobutamine can detect viable myocardium in patients after thrombolytic therapy. However, there is no detailed information on the use of this method in patients with chronic left ventricular dysfunction without reperfusion.Methods. We studied 33 selected patients with angiographically proved coronary artery disease and persistent left ventricular dysfunction. The effect dobutamine infusion (5 μg/kg body weight per min, followed by 10 μg/kg per min) on left ventricular wall motion was evaluated by transthoracic echocardiography before coronary artery bypass grafting and compared with that obtained immediately after the operation (evaluated by intraoperative echocardiography) and both 2 weeks and 3 months later. Left ventricular wall motion was analyzed qualitatively by dividing the left ventricle into 16 segments, and a score was assigned to each region.Results. Before coronary artery bypass surgery, 314 segments were akinetic. Of these, 183 became normokinetic immediately after revascularization and 15 became hypokinetic. Dobutamine infusion was able to predict improvement in 178 of the 205 segments that recovered function after revascularization (sensitivity 86.8%) and to identify 89 of the 109 segments that did not recover postoperatively (specificity 81.6%). Mean (±SD) segment scores were 2.24 ± 0.35 at baseline, 1.49 ± 0.34 (p < 0.001) after dobutamine infusion, 1.51 ± 0.38 (p < 0.001) immediately after and 1.51 ± 0.38 (p < 0.001) 2 weeks after coronary artery bypass and 1.55 ± 0.37 (p < 0.001) at 3-month follow-up.Conclusions. Echocardiography during infusion of low dose dobutamine is a safe and accurate method for identifying reversible dysfunctioning myocardium and predicts early reversibility of wall motion after surgical revascularization in selected patients with coronary artery disease with chronic left ventricular dysfunction.     

Effect of dobutamine stress echocardiography on mitral regurgitation

Objectives. This study was performed to examine the effect of dobutamine stress echocardiography on mitral regurgitation and to test the hypothesis that mitral regurgitation will increase in patients with an ischemic response.Background. New or worsening mitral regurgitation during stress testing has been proposed as a marker of ischemia. However, it is unclear whether ischemia induced by dobutamine is associated with mitral regurgitation because the hemodynamic effects of dobutamine may vary with regard to mitral regurgitation, depending on left ventricular function and maximal dose attained.Methods. Dobutamine stress echocardiography was performed in 102 consecutive patients with suspected or known coronary artery disease. Color flow Doppler was used to determine the presence and change in mitral regurgitation at baseline and peak dobutamine infusion (up to 40 μg/kg body weight per min). The mitral regurgitation color flow Doppler area was semiquantitatively graded as mild (<4 cm²), moderate (4 to 8 cm²) or severe (>8 cm²). Patients were assigned to ischemic and nonischemic groups according to the dobutamine stress echocardiographic results.Results. The two groups achieved the same maximal dose and demonstrated similar blood pressure and heart rate responses to dobutamine infusion. Only two patients developed new mitral regurgitation during dobutamine infusion, and both had a normal dobutamine echocardiographic result. More patients without ischemia had no mitral regurgitation compared with patients with ischemia. There was an insufficient number of patients with coronary angiographic data to determine the effects of mitral regurgitation on the sensitivity and specificity of dobutamine stress echocardiography. Of 23 patients with a rest ejection fraction <50%, 61% had an improvement in mitral regurgitation grade compared with 25% of patients with a rest ejection fraction ≥50% (p < 0.02).Conclusions. These data indicate that although dobutamine infusion often improves mitral regurgitation in patients with left ventricular dysfunction during stress echocardiography, it does not induce or worsen mitral regurgitation in those who demonstrate an ischemic response. Future studies are necessary, with larger numbers of patients, to determine the effects of mitral regurgitation on the sensitivity and specificity of dobutamine stress echocardiography.     

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)     

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.     

Stress echocardiography

Stress echocardiography has become an accepted noninvasive method for the diagnosis of coronary artery disease. Stress echocardiography is more sensitive than exercise electrocardiography and as sensitive and specific as radionuclide perfusion studies for detecting coronary artery disease. Pharmacologic stress echocardiography using dobutamine also has excellent diagnostic accuracy for patients who are unable to exercise. Dobutamine stress echocardiography can provide prognostic data to determine perioperative cardiac risks in patients who are undergoing vascular surgery.     

Dobutamine stress echocardiography: initial experience of a Canadian centre.

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

Comparison of squatting stress echocardiography and dobutamine stress echocardiography for the diagnosis of coronary artery disease

Background: Dobutamine stress echocardiography (DSE) is commonly used for the diagnosis for coronary artery disease (CAD). We previously demonstrated that squatting induces wall motion abnormalities (WMA) in areas subtended by stenotic coronary arteries. Objective: This study was designed to test the hypothesis that dobutamine and squatting stress echocardiography are equally useful for the diagnosis of CAD. Methods: We studied 39 patients who were scheduled to have coronary angiography for the evaluation of chest pain. Each patient had squatting stress echocardiography followed by DSE. For squatting stress echocardiography the echocardiogram in standard views was recorded in the standing position. The procedure was repeated during squatting for 2 minutes. Dobutamine echocardiography was performed using standard protocol. The squatting and dobutamine stress echocardiograms were interpreted by an observer blinded to the results of coronary angiography. Results: During squatting, new or worsening WMA developed in 20 patients. Six patients developed WMA in the left anterior descending artery territory, three in circumflex territory, three in the right coronary artery territory, and eight in multiple coronary territories. The sensitivity, specificity, and accuracy of squatting echocardiography for diagnosis of CAD were 95%, 94%, and 94%, respectively. For DSE, the sensitivity, specificity, and accuracy for the diagnosis of CAD were 85%, 94%, and 90%, respectively. There was no significant difference between squatting and dobutamine stress echocardiography for the diagnosis of CAD (P = 0.702). Conclusion: These data indicate that squatting and dobutamine echocardiography are equally useful in the diagnosis of CAD. In selected patients, squatting echocardiography may be used in place of dobutamine echocardiography for the diagnosis of CAD. (Echocardiography 2012;29:695–699)     

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.     

Enhanced detection of ischemic myocardium by transesophageal dobutamine stress echocardiography: comparison with simultaneous transthoracic echocardiography

The diagnostic accuracy of dobutamine stress echocardiography is limited in patients with poor transthoracic acoustic windows. Transesophageal echocardiography (TEE) overcomes these limitations and thus may increase the clinical usefulness of dobutamine stress echocardiography. The present study was designed to compare the diagnostic accuracies of transesophageal and transthoracic dobutamine stress echocardiography for the identification of coronary artery disease (CAD) in a cohort of patients with a higher incidence of poor acoustic windows. Forty-two male patients (mean age, 66 +/- 9 years) underwent dobutamine stress echocardiography with simultaneous transesophageal and transthoracic imaging. Coronary arteriography was performed in 28 patients (67%). Transesophageal imaging adequately visualized 99.6% of left ventricular segments compared with 76.2% visualized by transthoracic imaging (P < 0.0001). There was substantial agreement between the two techniques for segmental wall motion analysis at baseline (kappa 0.76; 95% CI, 0.70-0.82); however, at peak dobutamine dose, agreement was significantly reduced (kappa 0.62; 95% CI, 0.55-0.69). The sensitivity (88% vs 75%), specificity (100% vs 75%), and positive predictive value (100% vs 80%) for the identification of CAD were all superior for transesophageal imaging. Transesophageal imaging correctly identified 11 of the 12 patients (92%) with multivessel disease compared with 5 patients (42%) identified by transthoracic imaging (P < 0.03). There were no major complications. Transesophageal dobutamine stress echocardiography is a safe, feasible, and accurate technique for the identification and risk stratification of patients with CAD. Transesophageal imaging appears to be superior to transthoracic imaging for identifying both the presence and extent of CAD, specifically in patients with poor acoustic windows.     

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.     

Dobutamine positron emission tomography: Absolute quantitation of rest and dobutamine myocardial blood flow and correlation with cardiac work and percent diameter stenosis in patients with and without coronary artery disease

Objectives. This study sought to measure myocardial blood flow at rest and during dobutamine infusion and to correlate flow with cardiac work and severity of coronary artery disease.Background. Dobutamine is used with cardiac imaging to induced possible ischemia in patients with known or suspected coronary artery disease. Positron emission tomography permits noninvasive quantitation of myocardial blood flow.Methods. Fifteen patients with quantitative coronary arteriography were studied at rest and during dobutamine infusion using nitrogen-13 ammonia flow imaging with positron emission tomography. Myocardial blood flow was determined in regions corresponding to the three major coronary arteries for myocardium with and without dobutamine flow defects and with and without a >50% diameter stenosis.Results. Eight patients had at least one dobutamine flow defect; four of whom had a previous myocardial infarction. One patient with >50% diameter stenosis had no flow defects, and one with < 50% diameter stenosis (49%) had one defect. Dobutamine significantly increased myocardial blood flow in regions with and without a dobutamine flow defect or >50% diameter stenosis, with a greater increase when a defect or >05% diameter stenosis was not present. Rest and dobutamine flows in regions without >50% diameter stenosis were 0.93 ± 0.20 (mean ± SD) and 2.16 ± 0.52 ml/min per g (p < 0.01), respectively. The corresponding flows in regions without a defect were 0.94 ± 0.21 and 2.17 ± 0.53 ml/min per g (p < 0.01), respectively. This 2.4-fold increase in flow was significantly correlated (p < 0.001) with a 2.2-fold increase in rate-pressure product induced by dobutamine. The rest and dobutamine flows for regions subtended by a vessel with >50% diameter stenosis were 0.70 ± 0.33 and 1.20 ± 0.54 ml/min per g (p < 0.05), respectively, whereas the corresponding values for regions with a dobutamine flow defect were 0.69 ± 0.33 ml/min per g at rest and 1.23 ± 0.54 ml/min per g during dobutamine (p < 0.05). Dobutamine increased flow inversely proportional to percent diameter stenosis. The rest flow for regions with a dobutamine flow defect were not significantly different from that in regions without defects.Conclusions. Dobutamine resulted in a significant increase in myocardial blood flow that correlated significantly with both increased cardiac work and degree of stenosis.