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*

OBJECTIVETo evaluate the value of low-dose adenosine echocardiography (LDAE) for detection of myocardial viability in patients with acute myocardial infarction (MI).

METHODSThirty-six patients underwent LDAE within 3 - 10 days after onset of first acute MI before (n = 4) or after (n = 32) percutaneous coronary intervention. A 17-segment semi-quantitative scoring model was adopted. Wall motion improvement derived from two dimensional images at follow-up (2 - 3 months after acute MI) comparing baseline before adenosine infusion was used as gold criteria for myocardial viability.

RESULTSLow-dose adenosine slightly increased heart rates [(70.7 +/- 10.8) beats/min vs. (78.1 +/- 10.9) beats /min, P < 0.01] and also significantly reduced left ventricular endsystolic volume [(30.4 +/- 1.9) ml vs. (20.1 +/- 9.3) ml, P < 0.01] and increased ejection fraction (62.6% +/- 10.4% vs. 74.7% +/- 9.8%, P < 0.01). The sensitivity, specificity, diagnostic accuracy, positive and negative prective values of LDAE for identification of viable myocardium were 90.3%, 80.8%, 86.0%, 84.8% and 87.5%, respectively. Incidence of mild adverse reaction during LDAE was 38.9% (14/36). LDAE at dose of 100 microgxkg(-1)xmin(-1) was ideal in terms of balanced sensitivity and specificity for detecting viable myocardium without increasing the adverse effects compared to lower doses.

CONCLUSIONSLDAE (100 microgxkg(-1)xmin(-1)) has excellent sensitivity and specificity for detecting viable myocardium in acute MI with only minimal adverse effects.

BACKGROUND AND OBJECTIVES: Doppler myocardial imaging (DMI) has been suggested as a method of quantifying inducible ischemia during dobutamine stress echocardiography (DSE). Post-systolic motion (PSM) detected by DMI is related to peri-infarct ischemia during DSE. We hypothesized that PSM during DSE would predict recovery of dysfunctional myocardium after successful percutaneous coronary intervention (PCI). SUBJECTS AND METHODS: Thirty patients with dysfunctional myocardium in the left anterior descending coronary artery (LAD) territory were divided into two groups according to improvement of wall motion score index (WMSI) in the LAD territory at 6 months after successful PCI of the LAD. DMI was evaluated in the LAD territory during DSE. Fifteen patients showed improved WMSI (1.42+/-0.39) while the other 15 had unchanged WMSI (1.75+/-0.46) 1 month after PCI. Myocardial velocity was measured in the mid-septal, apico-septal, and basal anterior segments of the LAD artery territory. PSM was defined as a positive wave appearing after the curve of systolic ejection had reached the zero line. RESULTS: Although there was no difference between resting PSMs in both groups, PSM during DSE was significantly higher in the improved WMSI group than in the WMSI group where it was unchanged. CONCLUSION: PSM during DSE predicts recovery of dysfunctional myocardium after successful PCI.
Arteries ; Coronary Vessels ; Dobutamine ; Echocardiography, Stress ; Humans ; Ischemia ; Myocardial Stunning ; Myocardium ; Percutaneous Coronary Intervention

Tetrahydroisoquinoline(THI) alkaloids can be considered as cyclized derivatives of simple pthylamines and many of them, especially with 6,7-disubstitution, demonstrate relatively high affinity for catecholamines. In the present study, pharmacological action of limited series of THI has been examined using rat isolated atria and aorta. In addition, (H) prazosin displacement binding study with THI compounds using rat brain homogenates was performed to find out if these probes to have a-adrenoceptor affinity. In isolated rat atria, all THls and dobutamine increased heart rate and contractile force. In the presence of propranolol, the concentration response curves of YS 49 and YS 51 shifted to the right resulting in 8.07+0.84 and 7. 93+0.11 of pA values, respectively. The slope of each compound was not deviated from unity, indicating that these chemicals are highly competitive at the cardiac beta1-adrenoceptors. YS 49, YS 51 and higenamine showed alpha1- adrenoceptor affinity in rat brain in which the dissociation constant(K,) was 2.75, 2.81 and 1.02pM, respectively. It is concluded, therefore, that THI alkaloids have considerable affiniyt to alpha1-adrenoceptors in rat aorta and atria. while these probes show relatively high affinity for cardiac beta1-adrenoceptors. The authors speculate that it is worthy investigating whether these chemicals are useful in the management of vasospasm of aneurysmal subarachnoid hemorrhage.
Alkaloids* ; Animals ; Aorta* ; Brain* ; Catecholamines ; Dobutamine ; Heart Rate ; Prazosin ; Propranolol ; Rats* ; Subarachnoid Hemorrhage ; Vasodilation

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

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*