No abstract available.
Dobutamine* ; Echocardiography, Stress* ; Myocardium*

No abstract available.
Adenosine* ; Dipyridamole* ; Dobutamine* ; Exercise Test*

No abstract available.
Dobutamine ; Echocardiography, Stress ; Liver Transplantation ; Liver

No abstract available.
Coronary Stenosis* ; Coronary Vessels* ; Dobutamine* ; Echocardiography, Stress* ; Female ; Humans

No abstract available.
Coronary Artery Disease* ; Coronary Vessels* ; Diagnosis* ; Dobutamine* ; Echocardiography, Stress*

No abstract available.
Coronary Artery Disease* ; Coronary Vessels* ; Dobutamine* ; Echocardiography, Stress* ; Humans ; Myocardium* ; Tomography, Emission-Computed, Single-Photon*

BACKGROUND: The 3 minutes increment of dobutamine dose protocol is most commonly used method in dobutamine stress echocardiography (DSE). But the precise hemodynamic response to dobutamine dosage and its difference by extending stage duration have not been well elucidated. MATERIALS AND METHOD: Nineteen healthy voluntary subjects with a mean age of 23.9+/-4.7 years were included. All subjects underwent 3-minutes incremental and 5-minnutes incremental protocol of DSE at random order in a same day. Heart rate, blood pressure, stroke volume, fractional shortening, rate-pressure product and cardiac output were measured every 3 minutes in 3-min protocol of DSE. In 5-min protocol, same variables were measured at 3 minutes of each stage as well as at 5 minutes. RESULTS: 1) Heart rate did not increase until 10 microgram/kg/min dose and increased thereafter by increment of dobutamine dose. 2) Fractional shortening and stroke volume increased markedly from the 5 microgram/kg/min until 20 microgram/kg/min dose and showed slow increase or plateau at a higher dobutamine dose. 3) Systolic blood pressure, cardiac output and rate-pressure product increased continuously from initial dose to maximal dose. 4) Although by extending stage duration to 5 minute in 5-min protocol produced greater hemodynamic effects than those measured at 3 minutes of each stage, there were no significant difference in the results of 3-min and 5-min protocol of DSE. CONCLUSION: The increase of cardiac contractility most contributed to increase of cardiac output until 20microgram/kg/min dose and the increase of herat rate contributed dominantly thereafter, thus the hemodynamic variables showed different responses to increment of dobutamine dose. There were no significant difference in hemodynamic effects between the two protocols. So it is considered that 3-min protocol of DSE gives similar hemodynamic information as 5-min protocol and is more time-saving method.
Blood Pressure ; Cardiac Output ; Dobutamine* ; Echocardiography, Stress* ; Heart Rate ; Hemodynamics* ; Stroke Volume

We studied to investigate the predictive values of gated SPECT for the improvement of wall motion after bypass surgery. As we compared postoperative SPECT with preoperative ones, we defined viability as wall motion improvement. We performed rest 71-201/stress Tc-99m-MIBI gated SPECT in 25 patients before and 3 months after bypass surgery. Myocardial wall motion was graded as normal, hypokinesia, akinesia, and dyskinesia by pair-wise visual analysis of gated pre and postoperative SPECT's on the same monitor screen. Myocardial wall thickening was determined good or poor Among 92 segments with wall motion abnormalities before operation, 69 (75%) improved and 23 did not. Before operation, we could find segments with good systolic thickening in 64 segments among total 92. Thickening of the remaining 28 was poor. Wall motion improved postoperatively in 45 segments (70%) among 64 with good thickening. Twenty four(86%) among 28 segments with poor thickening had also improved. We grouped segments into mild(hypokinetic) and severe(akinetic/dyskinetic) ones. Among 33 segments with severe motion abnormalities, 14 had good thickening and 19 did not. Nine(60%) improved out of 14 segments having severe abnormality with good thickening. However, 16(84%) segments out of 19 having severe abnormality with poor thickening also improved. Neither degree of perfusion decrease nor severity of wall motion abnormalities could explain the high rate of false negatives. In conclusion, as we defined viability as wall motion improvement by comparing pre and postoperative SPECT, systolic thickening observed by gated Tc-99m-MIBI SPECT in myocardial segments with wall motion abnormalities predicted wall motion improvement after bypass surgery. However, poor thickening could not be referred as evidence of nonviable myocardium both in mild and severe contractile dysfunction, so that we might need stimulation study such as dobutamine echocardiography or dobutamine gated SPECT.
Dobutamine ; Dyskinesias ; Echocardiography ; Humans ; Hypokinesia ; Myocardium ; Perfusion ; Tomography, Emission-Computed, Single-Photon*

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.
Catheterization ; Catheters ; Coronary Vessels ; Dobutamine* ; Echocardiography* ; Humans ; Microvessels ; Myocardial Infarction* ; Myocardial Ischemia ; Myocardium

> BACKGROUND: The accuracy of flow-related changes in aortic valve area (AVA) determined by the Gorlin formula or the continuity equation remains disputable. However, anatomic AVA can be determined by using by direct planimetry of transesophageal echocardiography (TEE). The purpose of this study was to assess the impact of changes in flow on AVA determined by TEE using direct planimetry. METHOD: Determination of AVA by TEE using direct planimetey was performed intraoperatively under three different hemodynamic conditions - pre-dobutamine (baseline) period, post-dobutamine period, post-CABG period - in 17 CABG patients and cardiac output (CO) with left ventricular ejection fraction (EF) were also determined by TEE simutaneously. The changes in aortic flow were induced by dobutamine infusion. RESULTS: AVA at pre-dobumaine period, post-dobutamine period, and post-CABG period were 2.99+/-0.80 cm2, 3.01+/-0.79 cm2, and 3.01+/-0.80 cm2, respectively. Before dobutamin infusion, CO and EF were 2.01+/-0.64 L/min and 47+/-10%. After dobutamine infusion, CO and EF were 3.03+/-1.05 L/min, 54+/-9% respectively and significantly increased by 54%, 18% than those measured before dobutamine infusion (p<0.01, p<0.01), respectively. After CABG, CO and EF were 3.86+/-1.86 L/min and 58+/-11% and also significantly increased by 98%, 26% than those measured before dobutamine infusion (p<0.01, p<0.01), respectively. However, despite of these significant hemodynamic changes, there were no significant changes in AVA and no significant correlations between these hemodynamic and AVA changes, neither at post-dobutamine period nor post-CABG period. CONCLUSION: The acute changes in CO and EF do not result in significant alterations in the anatomic AVA determined by TEE using direct planimetry. Thus, TEE using direct planimetry could be accurate and useful in the determination of AVA in hemodynamically unstable patient.
Aortic Valve* ; Cardiac Output* ; Dobutamine ; Echocardiography, Transesophageal* ; Hemodynamics ; Humans ; Stroke Volume*