Dobutamine Echocardiography in Chronic Coronary Artery Disease with Left Ventricular Dysfunction

BACKGROUND: Dobutamine echocardiography has been shown to be a valuable tool for determining myocardial viability in both acute and chronic coronary artery disease with left ventricular dysfunction. The purpose of the our study was to identify the role of dobutamine echocardiography in the prediction of improvement of regional left ventricular (LV) dysfunction after revascularization of chronic coronary artery disease. METHODS: Twenty-three patients (mean age 61.2+/-9.0 years;20 men) with chronic LV dysfunction underwent dobuta-mine echocardiography (dobutamine:baseline, 5, 10, 20 microgram/Kg/min) before coronary revascularization (coronary artery bypass graft surgery 16, percutaneous coronary angioplasty 7). The mean LV ejection fraction was 42.9+/-8.8% with ranging from 26% to 58%. Follow-up echocardiography was performed at 2 to 21 months (mean 9.0+/-6.2 months) after revascularization. RESULTS: During dobutamine echocardiography, there was no major complication. Improvement of the dysfunctional myocardium was observed in 12 of 23 patients in dobutamine echocardiography. Among them, 10 patients showed functonal recovery after revascularization. Another 11 patients did not show improvement of dysfunctional myocardium in dobutamine echocardiography, however 3 of them showed functional recovery after revascularization. One hundred fifteen dysfunctional segments were found in 368 segments of 23 patients, and improvement of wall motion abnormality was observed in 46 of 115 segments in dobutamine echocardiography. Among them, 31 segments showed functional recovery after revascularization. Another 69 segments did not show wall motion improvement in dobutamine echocardiography. But among them, 13 segments showed functional recovery after revas-cularization. The sensitivity and specificity of dobutamine echocardiography for the prediction of postoperative improvement of segmental wall motion were 70% and 79%, respectively. The positive and negative predictive value of dobutamine echocardiography were 67% and 81%, respectively. CONCLUSION: In patients with chronic LV dysfunction, dobutamine echocardiography can be used as a predictor of the improvement of dysfunctional segments after revascularization.

Prognostic value of dobutamine echocardiography in prediction of late recovery of regional myocardial dysfuction in patients with acute myocardial infarction

BACKGROUND AND OBJECTIVES: Determining the presence of viable myocardium has prognostic and therapeutic implications in the treatment of acute myocardial infarction (AMI). The aim of this study was to assess the ability of dobutamine echocardiography (DE) to detect viable myocardium and predict the late improvement of regional left ventricular dysfunction after AMI. METHODS: Twenty-five patients (male 24, mean age 57+/-9.6) with AMI underwent DE (dobutamine: 0, 5, 10 and 20 microgramm/kg/min) in 4.8+/-2.2 days after infarction. Revascularization of infarct related artery was performed in 20 patients (percutaneous coronary angioplasty 18, coronary artery bypass graft surgery 2). A follow-up 2D-echocardiography was performed at 7.1+/-2.3 months after AMI. RESULTS: 1. Improvement of regional wall motion abnormality (RWMA) was observed in 12 patients during DE[DE (+) group]. Thirteen patients showed no improvement of RWMA[DE (-) group]. 2. In follow-up 2D-echocardiography 10 patients showed improvement of RWMA among DE (+) group (positive predictive value= 83.3%). Two patients showed improvement of RWMA among DE (-) group (negative predictive value=84.6%). Sensitivity and specificity of DE in predictiong late recovery of RWMA were 83.3% and 84.6% each. DE performed in the early stage of AMI seems to be useful in prediction of late recovery of regional left ventricular dysfunction.

Intraoperative Low-dose Dobutamine Echocardiography Predicts the Post-pump Response of Dysfunctioning Myocardial Segments to Coronary Artery Bypass Grafting

BACKGROUND: Low dose dobutamine echocardiography has recently been introduced for use in identification of viable myocardium in patients with acute myocardial infarction and prediction of the response of dysfunctioning myocardial segments to coronary angioplasty. The aim of this study was to evaluate wheter tihs test could be used to predict the early response of dysfunctioning myocardial segements to coronary artery bypass grafting(CABG). METHODS: We studied in 23 patients with multi-vessel disease during CABG. Myocardial segments were monitored by intraoperative transesophageal echocardiography(TEE) in the transgastric short-axis view at papillary muscle level. The left ventricle was divided into five segments and sixty eight myocardial segments in 23 patients were analyzed. Percentage of systolic wall thickening(PSWT) was calculated in each segment for three times: at basline(early after pericardiectomy);before bypass during dobutamine infusion(3-5ug/kg/min);and after seperation from cardiopulmonary bypass. Segments showing baseline PSWT >_30% were considered normal and those _10% during dobutamine infusion were considered responders and those 30%(normal) and 44(68%) had PSWT _10%(from 12.3+/-7.2% to 33.5+/-11.8%, p<0.01 ; responder segments), and 23(52.3%) showed increase in PSWT < 10%(from 14.7+/-6.5% to 17.4+/-7.4%, p=NS ; nonresponder segments). After CABG, responder segments showed a significant increase in PSWT in comparison with baseline values(from 12.3+/-7.2% to 32.1 +/-11.0%,p<0.01). Segments not responded to dobutamine showed no significant changes in PSWT after CABG(from 14.7+/-6.5% to 16.0+/-8.2%, p=NS). Twenty-four normal segments (PSWT 41.9+/-6.2%) showed a slight but significant reduction in PSWT both during dobutamine infusion(38.7+/-6.9%;p<0.05) and after CABG(38.9+/-6.3%, p<0.05), suggesting that compensatory hyperfunction was present at baseline. Estimation of clinical accruacy of low dose dobutamine TEE yieded to 69% sensitivity, 93.9% specificity, 95.2% positive predictive value, 60.9% negavive predictive value, and 77.3% overall accuracy. In both responders and nonresponders of dysfunctioning segments, there was a correlation between PSWT during dobutamine infusion and that after CABG(r=0.61, r=0.63, respectively). CONCLUSION: Low dose dobutamine TEE test well predicts the early response of dysfunctioning myocardial segments to CABG.

Dobutamine Echocardiography in the Prediction of Left Ventricular Remodeling after Acute Myocardial Infarction

BACKGROUND: Left ventricular remodeling after acute myocardial infarction has been identified as an important prognostic factor because it leads to ventricular enlargement, ventricular aneurysm, and increased mortality. However predictors of left ventricular remodeling are not clearly defined. This study was perforrned to evaluate the efficacy of dobutamine echocardiography in the prediction of left ventricular remodeling in patients with acute myocardial infarction. METHODS: Forty-five patients(39 males, age 56.9+/-10.2 years) with acute myocardial infarction(AMI) and patent infarct-related artery(no significant narrowing with/without revascularization) underwent dobutamine echocardiography at 2 7 days after AMI. The stages of dobutamine infusion were baseline, 5, 10, 20ug/kg/min, and images at each stage were directly compared and analyzed with the use of 16-segment model(by American Society of Echocardiography) and scoring system(1: normal, 2: mild to moderate hypokinesia, 3: severe hypokinesia, 4: akinesia, 5: dyskinesia). The viability of infarct zone was defined as improvement of wall motion score in more than 2 contiguous segments during dobutamine infusion in areas of resting asynergy. Coronary angiography was performed at 7~10 days after AMI and revascularization of infarct-related artery was done, if severe stenosis was present. Follow-up(F/ U) echocardiography was performed more than 3 months after AMI. We have measured left ventricular end-diastolic and end-systolic volume at baseline, dobutamine(peak dose) and follow-up echocardiography by modified Simpsons method. RESULTS: 1) Dobutamine echocardiography was performed at 5.5+3.9 days after acute myocardial infarction, and follow-up echocardiography was performed at 7.5+3.4 months after dobutamine echocardiography. 2) We assessed left ventricular end-diastolic volume(LVEDV) at follow-up echocardiography compared to LVEDV at baseline echocardiography, and patients were divided into 2 groups. Group 1(n=14) with increase in LVEDV during F/U period(mean change 13.9+14.2ml); Group 2(n=31) with no increase in LVEDV volume during F/U period(mean change 27.4+22.1). Between two groups, clinical parameters such as age, sex, incidence of anterior myocardial infarction, incidence of non-Q myocardial infarction, peak CK, peak CKMB, pre-infarction angina, incidence of reperfusion therapy, follow-up duration, were not significantly different. 3) Between group 1 and group 2, there were no singnificant differences in baseline echocardiographic parameters such as ejection fraction, wall motion score index, LVEDV, LV enddiastolic dimension. 4) In group 1, the incidence of patients with infarct zone viability assessed by dobutamine echocardiography was significantly snialler than the one in group 2(5 of 14 and 21 of 31, respectively, p <0.05). 5) Beween group 1 and group 2, the change of LVEDV at dobutamine echocardiography compared to LVEDV at baseline echocardiography was significantly different( -1.3+/-17.7 and -17.1+/-26.2, respectively, p<0.05). 6) Linear regression analysis indicated that the change of LVEDV during follow-up period was predicted by the change of LVEDV during dobutamine echocardiography. LVEDV(F/U) LVEDV(baseline) = 0.726[LVEDV(dobutamine) LVEDV(baseline) ] 5.648(r=0.65, p<0.05) CONCLUSION: The viability of infarct zone assessed by dobutamine echocardiography was predictive of left ventricular remodeling at F/U of acute myocardial infarction and the change in LVEDV during dobutamine echocardiography correlated with the change in LVEDV at follow-up of acute myocardial infarction. Dobutamine echocardiography can be an useful tool for the prediction of LV remodeling after acute myocardial infarction.

Comparison of Dobutamine Echocardiography and Contrast Echocardiograph in Patients with Myocardial Infarction

BACKGROUND: Dobutamine echocardiography is a useful method to detect myocardial viability in ischemic heart disease. Recently myocardial contrast echocardiography(MCE) is reported to be a new method to evaluate myocardial viability by assessing microvascular integrity of dysfunctional myocardium. We hypothesized if the microvascular integrity is maintained, the dysfunctional myocardium would improve its function by dobutamine infusion. METHOD: 10 myocardial infarction patients (acute : old=8 : 2, M : F=7 : 3, mean age=61+/-11yr) were included in the study. 2 dimensional echocardiography was performed before and during dobutamine infusion and after contrast injection to right and left coronary arteries in the catheterization laboratory. Echocardiographic analysis was done in parasternal short, apical 4 and 2 chamber views. Left ventricule was devided by 20 segments from 3 views. In each segment, will motion score(graded 1, normal, to 5, dyskinesia) before and after dobutamine infusion and opacification grade(0, 0.5, 1 denoting no, intermediate and normal opacification respectively) was compared. RESULTS: The number of segments with abnormal wall motion at baseline were 57 segments. 5 segments was exciuded due to poor image quality. Among 52 segments, 25 segments improved it's function during dobutamine infusion. Improvement of regional function was more frequent in hypokinetic segments than akinetic or dyskinetic segments (69% vs 15%). The improvement of dysfunctional regional wall motion by dobutamine infusion was observed in 80%(19/24), 67%(6/9) and 5%(1/19) of normally, intermediately and none opacified segment respectively. The correlation between wall motion score with opacification grade was 0.598 at baseline and increased to 0.766 after dobutamine infusion. CONCLUSION: In patients with myocardial infarction the dysfunctional segments but intact microvasculature assessed myocardial contrast echocardiography improves function by dobutamine infusion. These findings myocardial contrast echocardiography would be a useful method to detect myocardial viability.

Comparison Study of Dipyridamole and Dobutamine Stress Echocardiography in Same Patients

BACKGROUND: The two most commonly used drugs as a stressor during wtress echocardiography are dipyridamole and dobutamine. The purpose of this study was to compare diagnostic accuracies of dipyridamole and dobutamine stress echocardiography for fixed coronary artery disease and evaluate complications related to the two agents in the same patients. METHODS: 30(M : 5=19 : 11, age=56+/-8.8yr) consecutive patients without history of previous myocardial infarction underwent coronary angiography, dipyridamole and dobutamine stress echocardiography in random order. Dipyridamole was infused up to 0.84mg/Kg for 10 minutes during clinical, ECG and echocardiographic montioring. Dobutamine was infused in dose increments from 5 to 40microg/Kg/min under the same condition. Positive criteria for myocardial ischemia by echocardiography was now regional wall mation abnormatity or worsening of regional wall motion after stress. Significant coronary disease was defined as more than 70% stenosis by coronary angiography. RESULTS: The sensitivity and specificity of both stress echocardiography were same, 82% and 92% respectively. In a single vessel disease the sensitivity of dipyridamole echocardiography was 75% and dobutamine echocardiography was 83% without statistical difference. The correlation of ischemic free time during both stress test was 0.375. During dipyridamole infusion no test was prematurely terminated because of side effects, but 3 patients(10%) developed severe hypertension and ventricular arrytricular arrythmia during dobutamine infusion and test was terminated. CONCLUSION: Thus, by this prospective direct comparison of both stress test, dipyridamole and dobutamine stress echocardiography have similar diagnostic accuracies for the detection of coronary artery disease. But during dobutamine infusion, careful monitoring for hemodynamic changes arrythmia is required for possible serious complications.