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1.
OBJECTIVE—To assess the prognostic value of stress echocardiography as an adjunct to exercise electrocardiography in patients with uncomplicated acute myocardial infarction.
DESIGN—496 patients underwent a maximum exercise ECG and pharmacological stress echocardiography (406 dobutamine and 90 dipyridamole) within 15 days of uncomplicated acute myocardial infarction and were followed for a mean of 25 months (range 1-74 months) for reinfarction, unstable angina, and cardiac death. Patients undergoing revascularisation were omitted.
RESULTS—Exercise ECG was positive in 162 patients (32.6%) and low threshold positive (< 100 W) in 91 (18%). Stress echocardiography was positive in 239 patients (48%) (194 with dobutamine and 45 with dipyridamole stress). The agreement between the two tests was 63% (κ = 0.24, 95% confidence interval 0.15 to 0.33). Sixty nine spontaneous events occurred (14 cardiac deaths, 26 reinfarctions, and 29 with unstable angina requiring hospital admission), and 126 patients underwent revascularisation (39 coronary angioplasty and 87 bypass surgery). By receiver operating characteristic curve analysis, stress echocardiography provided incremental prognostic information compared with clinical data. A low threshold positive exercise ECG was associated with a worse outcome, but there was a fivefold increase in risk in patients with positive stress echocardiography who also had a high threshold (> 100 W) positive exercise ECG. Event-free survival of patients with both tests positive was significantly less than in patients with only one positive test or with both tests negative.
CONCLUSIONS—Stress echocardiography provides additional prognostic information after uncomplicated acute myocardial infarction, but the greatest gain is found in patients with a high threshold positive exercise ECG.


Keywords: risk stratification; myocardial infarction; stress echocardiography; exercise stress testing  相似文献   

2.
OBJECTIVE—To determine whether, compared with fundamental imaging, second harmonic imaging can improve the accuracy of dobutamine stress echocardiography for identifying viable myocardium, using nuclear imaging as a reference.
PATIENTS—30 patients with chronic left ventricular dysfunction (mean (SD) age, 60 (8) years; 22 men).
METHODS—Dobutamine stress echocardiography was carried out in all patients using both fundamental and second harmonic imaging. All patients underwent dual isotope simultaneous acquisition single photon emission computed tomography (DISA-SPECT) with 99mtechnetium-tetrofosmin/18F-fluorodeoxyglucose on a separate day. Myocardial viability was considered present by dobutamine stress echocardiography when segments with severe dysfunction showed a biphasic sustained improvement or an ischaemic response. Viability criteria on DISA-SPECT were normal or mildly reduced perfusion and metabolism, or perfusion/metabolism mismatch.
RESULTS—Using fundamental imaging, 330 segments showed severe dysfunction at baseline; 144 (44%) were considered viable. The agreement between dobutamine stress echocardiography by fundamental imaging and DISA-SPECT was 78%, κ = 0.56. Using second harmonic imaging, 288 segments showed severe dysfunction; 138 (48%) were viable. The agreement between dobutamine stress echocardiography and DISA-SPECT was significantly better when second harmonic imaging was used (89%, κ = 0.77, p = 0.001 v fundamental imaging).
CONCLUSIONS—Second harmonic imaging applied during dobutamine stress echocardiography increases the agreement with DISA-SPECT for detecting myocardial viability.


Keywords: dobutamine stress echocardiography; second harmonic imaging; 18F-fluorodeoxyglucose imaging; myocardial viability  相似文献   

3.
Objective—To assess possible ECG changes caused by dobutamine stress and their relation to wall motion disturbances in patients with coronary artery disease.
Design—Prospective recording and analysis of 12 lead ECG at rest and during each stage of dobutamine stress echocardiography, and correlation with wall motion changes.
Setting—A tertiary referral centre for cardiac disease equipped with non-invasive facilities for pharmacological stress tests.
Subjects—27 patients, mean (SD) age 60 (8) years, with documented evidence of coronary artery disease in whom dobutamine stress echo was clinically indicated, and 17 controls of similar age.
Results—In controls, all ECG intervals shortened with increasing heart rate but in the patient group only PR and QT intervals shortened while QRS duration broadened and QTc interval prolonged progressively. In the 27 patients, 16 developed chest pain, 15 with reduced left ventricular long axis systolic excursion (p < 0.001), and all showed reduced peak lengthening rate; ST segment shift appeared in 16, 13 of whom developed chest pain, but did not correlate with reduction of either systolic long axis excursion or peak lengthening rate; QRS duration broadened in 20, 16 with reduction of long axis excursion (p < 0.02) which was more often seen at the septum (p < 0.005); QTc interval prolonged in 19, all of whom had associated reduction of peak long axis lengthening rate (p < 0.02).
Conclusions—QRS duration and QTc interval both normally shorten with dobutamine stress, while in coronary artery disease they both lengthen: changes in QRS duration correlate with systolic and QTc interval with diastolic left ventricular wall motion disturbances. ST segment shift also occurred in most patients, but without consistent correlation with wall motion abnormalities. It was thus less discriminating than the other two abnormalities in this respect.

Keywords: long axis;  QRS duration;  QTc interval;  stress echocardiography;  coronary artery disease  相似文献   

4.
OBJECTIVE—To evaluate the efficiency of the new technique colour Doppler tissue imaging (DTI) by studying the concordance between dobutamine DTI, standard grey scale echocardiography (SE), and rest-reinjection TI-201 tomography (TI) in dysfunctional myocardium.
PATIENTS—23 patients with chronic wall motion abnormalities and proven coronary artery disease (> 70% diameter stenosis of at least one major coronary artery at angiogram).
METHODS—The contractile reserve and the resting perfusion characteristics of dysfunctional myocardial segments were assessed with low dose dobutamine SE and/or DTI (2.5 up to 20 γ/kg/min) and TI on a semiquantitative basis. The DTI or SE data were separately compared with TI, on the basis of a 13 segment ventricular model. The resulting score of combined DTI and SE was also compared with TI. Finally the results obtained from DTI were compared with SE.
RESULTS—A total of 142 severely hypokinetic or akinetic segments were visualised. The viability study was feasible in 127 (89%) and 121 (85%) segments with DTI and SE, respectively. TI detected viability more frequently than DTI (84 v 61, p < 0.001) and SE (80 v 50, p < 0.001). However, as many viable segments were detected with combined DTI and SE as with TI (78 v 84, NS). The κ values between TI and SE, DTI or combined SE and DTI were 0.38, 0.45, and 0.57, respectively, and increased to 0.52 and 0.76, respectively, for SE and DTI versus TI when mid-anterior and mid-inferior segments only were considered. The κ value between SE and DTI was 0.34.
CONCLUSIONS—DTI is a helpful adjunct to SE, when using low dose dobutamine. This combination revealed as many viable segments as TI and showed a better agreement than DTI or SE alone for the assessment of myocardial viable segments evidenced by TI.


Keywords: colour Doppler tissue imaging; hibernating myocardium; thallium 201 single photon emission computed tomography; stress echocardiography  相似文献   

5.
Objective—To assess whether inotropic stress myocardial perfusion imaging, echocardiography, or a combination of the two could enhance the detection of multivessel disease, over and above clinical and exercise electrocardiographic data.
Design—100 consecutive patients investigated by exercise electrocardiography and diagnostic coronary arteriography underwent simultaneous inotropic stress Tc-99m sestamibi SPECT (MIBI) imaging and echocardiography. MIBI imaging and echocardiographic data were analysed using a 12 segment left ventricular model, and each segment was ascribed to a particular coronary artery territory. The presence of perfusion defects with MIBI imaging or of wall thickening abnormality with echocardiography in at least two coronary artery territories at peak stress was taken as diagnostic of multivessel disease. Arteriographic evidence of  50% stenosis was considered significant.
Results—56 patients had multivessel disease. The sensitivity of the combination of MIBI imaging and echocardiography for detecting this was greater than either MIBI imaging or echocardiography alone (82%, 68%, and 68%, respectively; p = 0.005). Clinical and exercise electrocardiographic variables gave an R2 value of 18.2% for predicting multivessel disease. The addition of either MIBI imaging (R2 = 29.2%; p = 0.002) or echocardiography (R2 = 28.8%; p < 0.001) enhanced the detection of multivessel disease, and the inclusion of both had further incremental value (R2 = 34.8%; p = 0.003). Age (p = 0.03), MIBI imaging (p = 0.007), and echocardiography (p = 0.001) were independent predictors of multivessel disease.
Conclusions—The assessment of both myocardial perfusion and contractile function by simultaneous inotropic stress MIBI imaging and echocardiography optimises the non-invasive detection of multivessel disease.

Keywords: multivessel disease;  inotropic stress;  SPECT imaging;  echocardiography  相似文献   

6.
OBJECTIVE—To evaluate whether the predictive value of dobutamine echocardiography for assessing contractile reserve was altered by differing patterns of regional myocardial perfusion.
PATIENTS—31 consecutive patients with symptomatic congestive heart failure (left ventricular ejection fraction < 35%) caused by coronary artery disease.
SETTING—A district general hospital.
METHODS—Thallium-201 perfusion imaging and low dose dobutamine (5-15 µg/kg/min) echocardiography were performed and resting echocardiography was repeated three months after revascularisation. Perfusion pattern and systolic wall thickening were compared using a 12 segment left ventricular model.
RESULTS—Of the 273 severely dysfunctional segments, 106 (39%) showed a normal perfusion and 167 (61%) an abnormal pattern. After revascularisation, recovery occurred in 71 of the segments with a normal perfusion pattern, and in these a dobutamine response was observed in 61 (86%); recovery also occurred in 56 segments with a mild to moderate abnormality of perfusion, and in these a dobutamine response was seen in 46 (81%) (NS). After revascularisation, the positive and negative predictive values for recovery of dysfunctional segments, where the majority were abnormally perfused, were 88% and 86%, respectively. Systolic wall thickening score indices improved from (mean (SD)) 3.21 (0.58) to 2.6 (0.66) (p < 0.001) after revascularisation in dobutamine responsive patients (n = 24) compared with patients who did not show a dobutamine response (2.86 (0.65) and 3.13 (0.56), p = 0.61, respectively).
CONCLUSIONS—Dobutamine echocardiography predicted improvement of dysfunctional myocardium after revascularisation irrespective of the resting perfusion pattern seen.


Keywords: dobutamine echocardiography; perfusion; revascularisation  相似文献   

7.
OBJECTIVE—To evaluate the effects of chronic coronary occlusion on the accuracy of low dose dobutamine echocardiography in predicting recovery of dysfunctional myocardium after revascularisation.
DESIGN—Retrospective study.
SETTING—Tertiary referral centre.
PATIENTS—53 consecutive patients with  70% stenosis of the left anterior descending coronary artery (LAD) and regional ventricular dysfunction (group 1, non-occluded LAD; group 2, occluded LAD) who underwent dobutamine echocardiography.
INTERVENTIONS—26 patients underwent coronary artery bypass grafting and 27 had percutaneous transluminal coronary angioplasty.
MAIN OUTCOME MEASURES—Baseline studies before revascularisation included cross sectional echocardiography at rest and during dobutamine infusion (5-10 µg/kg/min), and coronary angiography. The dobutamine study was performed mean (SD) 35 (28) days before revascularisation. Echocardiography at rest was repeated 90 (48) days after revascularisation.
RESULTS—Of 296 dysfunctional segments, 63 in group 1 (43%; 63/146) and 69 in group 2 (46%; 69/150) (NS) improved at follow up. Mean (SD) regional wall motion score index decreased from 1.97 (0.48) (95% confidence interval (CI) 1.01 to 2.93) before revascularisation to 1.74 (0.52) (95% CI 0.70 to 2.78) at follow up in group 1 (p = 0.001), and from 2.12 (0.41) (95% CI 1.30 to 2.98) to 1.88 (0.36) (95% CI 1.16 to 2.60) in group 2 (p = 0.0006). In group 1, sensitivity (87% v 52%; p < 0.0001), negative predictive value (88% v 65%; p = 0.001), and accuracy (77% v 64%; p = 0.01) were all significantly higher than in group 2, despite the angiographic evidence of collaterals in patients with occluded vessels.
CONCLUSIONS—Dobutamine echocardiography shows reduced sensitivity in predicting recovery of dysfunctional myocardium supplied by totally occluded vessels. Thus caution should be used in selecting such patients for revascularisation on the basis of a viability assessment made in this way.


Keywords: dobutamine; coronary artery disease; viability; chronic occlusion  相似文献   

8.
Objective—Flow associated dilatation (FAD%) and intimal media thickness are established markers of early atherosclerosis. This study aimed to compare the ability of the non-invasive measurements FAD% and intimal media thickness to predict coronary artery disease.
Methods—FAD% and intimal media thickness were determined using high resolution ultrasound in 122 patients with clinically suspected coronary artery disease before coronary angiography. Results are given as mean (SD).
Results—Patients with coronary artery disease had reduced FAD% compared with those with angiographically normal coronary vessels (3.7 (4.1) v 7.0 (3.5)%, p < 0.001), whereas intimal media thickness tended to be increased in patients with coronary artery disease (0.58 (0.35) v 0.47 (0.11)mm, p = 0.054). There was a negative correlation between FAD% and intimal media thickness (R = −0.317, p = 0.0004). Receiver operating characteristic analysis showed that FAD%  4.5% predicted coronary artery disease with a sensitivity of 0.71 (95% confidence interval 0.61 to 0.80) and a specificity of 0.81 (0.58 to 0.95). In contrast, intimal media thickness showed a positive correlation with the extent of coronary artery disease (number of vessels with a lesion  50%) (R = 0.324, p = 0.0003), without a clear cut off point.
Conclusions—In patients with clinically suspected coronary artery disease, FAD% discriminates between the presence or absence of coronary artery disease, whereas intimal media thickness is associated more with the extent of coronary artery disease.

Keywords: coronary artery disease;  endothelial dysfunction;  intimal media thickness;  flow associated dilatation  相似文献   

9.
AIM—To evaluate the angiographic, myocardial perfusion, and wall motion abnormalities in patients with severe compared with mild worsening of regional function during dobutamine stress echocardiography (DSE) for evaluation of myocardial ischaemia.
METHODS—147 patients with significant coronary artery disease and new or worsening wall motion abnormalities during DSE were enrolled. Left ventricular function was evaluated using a 16 segment/4 grade score model where 1 = normal and 4 = dyskinesis. Simultaneous sestamibi SPECT myocardial perfusion imaging was performed in all patients.
RESULTS—Severe worsening of regional function (an increase in wall motion score of two grades or more in  1 segment) was detected in 37 patients, while 110 patients had mild worsening (an increase in wall motion score of no more than one grade in  1 segment). Patients with severe worsening of regional function had more stenotic coronary arteries (2.31 (0.8) v 1.97 (0.8) (mean (SD)) (p <0.05), a higher prevalence of left anterior descending coronary artery disease (95% v 73%) (p < 0.05), a higher resting wall motion score index (1.71 (0.42) v 1.51 (0.40) (p = 0.01), and more stress perfusion defects (3.8 (1.5) v 2.8 (1.5) (p < 0.001) compared with patients with mild worsening. Multivariate analysis identified the number of stress perfusion defects (p < 0.005, χ2 = 8.8) and the number of ischaemic segments on echocardiography (p < 0.05, χ2 = 4.3) as independent variables associated with severe worsening of regional function.
CONCLUSIONS—The grade of worsening of regional function during DSE predicts the underlying extent of myocardial perfusion abnormalities. The occurrence of severe worsening of regional function is associated with variables known to predict worse prognosis in patients with coronary artery disease.


Keywords: coronary artery disease; myocardial perfusion; ventricular function; echocardiography  相似文献   

10.
OBJECTIVE—To identify the effects of altered ventricular activation during dobutamine stress on left ventricular function in normal subjects and in patients with coronary artery disease, and to distinguish these from an inotropic response.
DESIGN—Prospective analysis of 12 lead ECG and echocardiogram at rest and at peak stress.
SETTING—Tertiary referral centre for cardiac disease equipped with non-invasive facilities for pharmacological stress testing.
METHODS—22 patients with coronary artery disease were compared with 17 age matched controls. Left ventricular ejection and filling patterns were assessed using Doppler echocardiography. Activation effects were correlated with relative left ventricular ejection and filling times, and the Z ratio ([left ventricular ejection + filling times]/RR interval). Inotropic response was measured from peak aortic acceleration.
RESULTS—In controls, QRS shortened (by 4 ms, p < 0.001), and total ejection and filling periods lengthened (by 2 s/min, p < 0.01 and 5 s/min, p < 0.001, respectively). The Z ratio thus increased and correlated with QRS shortening (r2 = 0.69). Peak aortic acceleration (PAA) increased by 135%, p < 0.001. In patients, QRS lengthened at peak stress (by 9 ms, p < 0.001). Total ejection and filling times did not change, but Z ratio fell, correlating with QRS prolongation (r2 = 0.65). Nevertheless, PAA increased by 63%, p < 0.001.
CONCLUSIONS—Relative ejection and filling times reflect ventricular activation at rest and during stress independent of changes in inotropic state. By contrast, peak aortic acceleration reflects the positive inotropic effect of dobutamine on the myocardium, regardless of changes in activation.


Keywords: stress echocardiography; ventricular activation; Z ratio; aortic acceleration  相似文献   

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