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Query: UMLS:C0022116 (ischemia)
 91,303 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Orthotopic liver transplantation is an established therapy for end-stage liver disease. This study evaluated the range of cardiovascular abnormalities in patients undergoing evaluation for orthotopic liver transplantation and determined the prognostic implications of abnormal echocardiographic features, including ischemia during dobutamine stress echocardiography, in predicting postoperative cardiac events. Two-dimensional echocardiography was performed in 190 patients for assessment of left ventricular function, valvular pathology, and pulmonary hypertension. Dobutamine stress echocardiography was performed in 165 patients for evaluation of inducible ischemia. Contrast echocardiography for detection of intrapulmonary shunting was performed in 125 patients at rest and in 99 during dobutamine stress. Left ventricular dysfunction, significant valvular regurgitation, and inducible ischemia were identified in <1O% of patients. Pulmonary hypertension, left ventricular hypertrophy and > or = moderate intrapulmonary shunting were present in 12%, 16%, and 26% of patients, respectively. Severe intrapulmonary shunting predicted death prior to transplantation (P=0.01). Of the 71 transplanted patients, major perioperative events included global left ventricular dysfunction in four patients and myocardial infarction in one patient with normal coronary arteries. No preoperative echocardiographic parameters, including ischemia on dobutamine echocardiography, predicted these perioperative events. No cardiac events related to obstructive coronary artery disease occurred in the 154 patients without ischemia on dobutamine stress echocardiography. The majority of patients with end-stage liver disease, including those with alcoholic cirrhosis, have normal cardiac function on two-dimensional echocardiography. Severe intrapulmonary shunting portends a poor prognosis in patients awaiting transplantation. A negative dobutamine stress echocardiogram appears useful in excluding patients at risk for perioperative cardiac events related to obstructive coronary artery disease.
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PMID:Two-dimensional and dobutamine stress echocardiography in the preoperative assessment of patients with end-stage liver disease prior to orthotopic liver transplantation. 861 Apr 15

There are no standard criteria for the diagnosis of myocardial ischemia in akinetic segments during dobutamine stress echocardiography (DSE). The aim of the study was to assess the relation between different responses of akinetic segments during DSE and ischemia assessed by thallium-201 single-photon emission computed tomography (SPECT). Dobutamine-atropine stress echocardiography with simultaneous stress-reinjection thallium-201 SPECT was performed in 67 patients with old myocardial infarction significant and coronary artery stenosis. Fourteen myocardial segments were matched for both DSE and SPECT. Ischemia on SPECT was defined as reversible thallium defects. In 257 akinetic segments, 4 patterns during DSE were identified: (1) biphasic response in 41 segments (16%), defined as improvement at low dose (5 to 10 microgram/kg/min) followed by worsening at high dose; (2) persistent akinesia in 155 segments (60%); (3) akinesia becoming dyskinesia in 39 segments (15%); and (4) sustained improvement in 22 segments (9%). Reversible thallium defects were detected in 21 segments (51%) in group 1, in 20 segments (13%) in group 2, none in group 3, and in 2 segments in group 4 (9%). The prevalence of reversible defects in biphasic segments was higher compared with other patterns (p <0.00001 vs groups 2 and 3, p <0.005 vs group 4). The ischemic perfusion defect score was significantly higher in group 1 than group 2. The positive predictive value of biphasic response for reversible thallium defects was similar to that of stress-induced dyssynergia in normal segments at rest (51% vs 58%). It is concluded that of the various responses of akinetic segments to dobutamine infusion, the biphasic response is associated with the highest prevalence and greatest severity of ischemic on thallium SPECT. Observation of contractile response at both low- and high-dose DSE is a valuable approach for the diagnosis of myocardial ischemia in akinetic segments.
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PMID:Relation between contractile response of akinetic segments during dobutamine stress echocardiography and myocardial ischemia assessed by simultaneous thallium-201 single-photon emission computed tomography. 864 45

Dobutamine stress echocardiography (DSE) was performed on 26 patients admitted for chest pain deemed at low risk for myocardial infarction. Pharmacologic stress in the emergency department on a 24-hour basis was administered by nurses and echocardiographic ultrasonographers with electrocardiograms and echocardiograms being interpreted through telemedicine relay by an off-site cardiologist. Target heart rate was achieved in 84% of patients with an average peak dobutamine dose of 48 microg/kg/min. Echocardiographic transmission to the cardiologist over standard telephone lines took 9 minutes per quad-screen cine-loop display. The entire protocol added 2.2 hours to the emergency room evaluation. The one patient out of 26 who had incipient myocardial infarction was diagnosed by resting echocardiography. The remaining 25 patients were found clinically to have no infarction or ischemia. Of these, 22 out of 25 had normal DSE in the emergency department; three had wall motion abnormalities on peak stress images. Another three patients had other cardiac diseases documented by echocardiography. Evaluation of chest pain on a 24-hour basis with DSE with telemedicine interpretation appears to be a rapid and safe means of screening patients at low risk in the emergency department. Further experience with this modality is needed before all patients should be enrolled or early discharge of patients on the basis of DSE can be advised.
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PMID:The feasibility of dobutamine stress echocardiography in the emergency department with telemedicine interpretation. 884 6

Determining the presence of viable myocardium has prognostic and therapeutic implications in the treatment of ischemic heart disease. Dobutamine stress echocardiography (DSE) is one possible technique to help identify both hibernating and stunned but viable myocardium. Low-dose dobutamine infusion has an increased inotropic effect, while higher doses cause both inotropic and chronotropic effects. Thus, at lower doses cardiac augmentation occurs, and at higher doses regions of ischemia may be produced in the presence of significant coronary artery disease. This is manifested echocardiographically as changes in segmental wall motion. In theory, therefore, areas of viable myocardium should show improved wall motion at low doses, and areas of irreversible myocardial damage will remain akinetic. Five studies have investigated DSE for determining viability in the setting of acute myocardial infarction, thus looking for stunned but viable myocardium. DSE was shown to compare favorably with positron emission tomography and was highly sensitive and specific for predicting functional myocardial recovery. Five additional studies examined DSE for determining the presence of hibernating myocardium. The sensitivity and specificity of DSE were found to range from 71 to 92% and from 73 to 93%, respectively. The benefits of DSE include lower cost, convenience to both patient and physician, additional ancillary information, and determination of the possible need for urgent revascularization. Limitations of DSE include occasional technical difficulty in obtaining and interpreting studies and the need for larger volumes of viable myocardium to detect changes predictive of functional recovery. Larger trials are currently underway to confirm DSE as a reliable technique for determining myocardial viability.
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PMID:The use of dobutamine stress echocardiography for the determination of myocardial viability. 886 33

We assessed the effect of dobutamine on left ventricoarterial coupling during acute regional ischemia. Using a conductance catheter, we analyzed the end-systolic pressure-volume relation (ESPVR) in anesthetized dogs. We calculated the slope of ESPVR (Ees), the slope of the end-systolic pressure-stroke volume relation (Ea), (Ea/Ees) and the ratio (work efficiency) of external work to pressure-volume area at base-line during ischemia induced by occlusion of the left anterior descending coronary artery and during low-dose (1-3 micrograms.min-1.kg-1) and high-dose (4-10 micrograms.min-1.kg-1)dobutamine infusions with ischemia. ESPVR shifted to the right without a change in Ees during ischemia. Dobutamine caused dose-dependent increases in Ees but did not affect the intercept of ESPVR. During ischemia, Ea/Ees increased and work efficiency decreased. Low-dose dobutamine was associated with a return in control for Ea/Ees and work efficiency. High-dose dobutamine increased Ees and Ea but produced no further increase in Ea/Ees or work efficiency. Low-dose dobutamine would appear to be the preferable regimen to achieve the optimal ventriculoarterial coupling in acute regional ischemia associated with mismatched ventriculoarterial coupling and depressed left ventricular work efficiency.
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PMID:Effect of dobutamine of ventriculoarterial coupling in acute regional myocardial ischemia in dogs. 896 67

This study compares the value of dobutamine stress echocardiography and 99m-technetium methoxyisobutyl-isonitrile (MIBI) single-photon emission computed tomography (SPECT) in the assessment of extent and location of coronary narrowing in patients with healed myocardial infarction. Dobutamine (up to 40 microg/kg/ min)-atropine (up to 1 mg) stress echocardiography (DSE) in conjunction with MIBI SPECT was performed in 72 patients (52 men, mean age 57 +/- 11 years) with healed myocardial infarction referred for evaluation of myocardial ischemia. Ischemia was defined as new or worsened wall motion abnormalities at DSE and reversible perfusion defects at MIBI SPECT. Significant stenosis (> or = 50% luminal diameter stenosis) of the infarct-related artery was detected in 45 patients and of other coronary arteries in 22 patients. Sensitivity and specificity of remote ischemia for diagnosis of remote coronary stenosis were 68% (95% confidence interval [CI] 57 to 80) and 93% (CI 86 to 99) for DSE, and 64% (CI 52 to 76), and 90% (CI 83 to 98) for MIBI SPECT, respectively. The positive predictive value and specificity of peri-infarction ischemia for the diagnosis of infarct-related artery stenosis were 89% (CI 81 to 97) and 82% (CI 73 to 92) for DSE, and 87% (CI 79 to 95) and 82% (CI 73 to 92) for SPECT, respectively. The agreement between both techniques was higher for the diagnosis of remote than peri-infarction ischemia (84% vs 66%, p = 0.02). It is concluded that in patients with myocardial infarction undergoing dobutamine stress testing, both echocardiography and MIBI SPECT are clinically useful methods for the diagnosis of remote and infarct-related coronary artery stenosis.
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PMID:Comparison of dobutamine stress echocardiography and 99m-technetium sestamibi SPECT myocardial perfusion scintigraphy for predicting extent of coronary artery disease in patients with healed myocardial infarction. 902 27

The diagnostic values of adenosine, dobutamine, and exercise radionuclide ventriculography (RNVG) in the detection of coronary artery disease (CAD), and the characteristics of those patients who showed myocardial ischemia during the infusion of adenosine or dobutamine were assessed in 41 patients with suspected CAD. Sensitivity, specificity, and accuracy, respectively, for detecting patients with CAD were 35 (p < 0.01 vs. exercise RNVG), 100 and 46% (p < 0.01 vs. exercise RNVG) with adenosine RNVG, 74, 100 and 78% with dobutamine RNVG and 88, 71 and 85% with exercise RNVG. There was a significant difference in physiologic parameters during the provocation of ischemia by adenosine versus exercise RNVG, although these parameters were similar by dobutamine and exercise RNVG. Stepwise discriminant analysis revealed that the number of stenotic vessels was an important and independent predictor for the myocardial ischemia induced by each stress; the peak filling rate was the only predictor for adenosine-induced ischemia. Dobutamine induced myocardial ischemia in a way similar to that of exercise, and was more useful than adenosine for pharmacologic stress RNVG. The mechanism of the adenosine-induced ischemia seemed to differ from that of the ischemia induced by dobutamine or exercise, and to be closely associated with left ventricular diastolic function.
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PMID:Comparison of adenosine, dobutamine, and exercise radionuclide ventriculography in the detection of coronary artery disease. 909 20

Dobutamine stress echocardiography (DSE) and exercise thallium-201 single-photon emission computed tomography (SPECT) were compared for the accuracy in detecting coronary artery disease (CAD) in 51 consecutive patients. Twenty-six (group 1) of the 51 patients achieved adequate exercise end points, and 25 (group 2) did not. There were 38 patients with angiographically documented CAD. The overall sensitivity of DSE and thallium-201 SPECT in detecting CAD was 92 and 76% (p = NS), and the specificity was 77 and 77% (p = NS), respectively. The sensitivity of DSE is the same as that of SPECT in group 1 (90 vs. 90%; p = NS) and higher than that of SPECT in group 2 (94 vs. 61%; p < 0.05). In patients with CAD without a history of acute myocardial infarction or pathological Q wave on resting electrocardiogram, the sensitivity of DSE is the same as that of SPECT in group 1 (82 vs. 82%; p = NS) and also higher than that of SPECT in group 2 (90 vs. 40%; p = 0.03). The sensitivity in detecting individual coronary artery lesions with DSE and thallium-201 SPECT was not affected by the exercise level. The agreement between DSE and thallium SPECT in detecting patients with CAD was 88% in group 1 (kappa = 0.69; p < 0.001) and 76% in group 2 (kappa = 0.45; p = 0.01). The agreement in detecting vascular territories with ischemia was 68% in group 1 (kappa = 0.30; p < 0.01) and 75% in group 2 (kappa = 0.33; p < 0.001). The agreement in detecting vascular territories with a scar was 87% in group 1 (kappa = 0.55; p < 0.001) and 85% in group 2 (kappa = 0.44; p < 0.001). In conclusion, the sensitivity and specificity of DSE in detecting CAD are similar to that of thallium-201 SPECT with an exercise level > or =85% of the maximal predicted heart rate. However, in patients who cannot exercise adequately, DSE is more accurate than thallium SPECT. The agreement between DSE and thallium SPECT in detecting patients with CAD and identifying ischemia of individual vascular territories is also affected by the exercise level.
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PMID:Dobutamine stress echocardiography compared with exercise thallium-201 single-photon emission computed tomography in detecting coronary artery disease-effect of exercise level on accuracy. 919 34

Left bundle branch block does not permit an easy diagnosis of coronary heart disease (CAD) with provocative non-invasive test such as bicycle or treadmill stress test. Echocardiography allows the identification of segmental wall motion by evaluating the movement as well the thickness of the segment examined. Due to its agonist action on beta 1 receptors, dobutamine causes an increase in myocardial oxygen consumption and, as a consequence, may reveal myocardial ischemia; on this basis, we evaluated the sensibility, specificity and diagnostic accuracy of dobutamine stress-echo in identifying CAD in patients with left bundle branch block, and compared results with those obtained from coronary catheterization. From February 1994 to September 1995 we observed 25 patients with left bundle branch block (17 men, 8 women, mean age 61.8 +/- 8.4 years, range 43.75), affected or suspected for CAD. All patients underwent dobutamine stress-echo test and coronary arteriography. We divided patients into two groups: the first one (11 patients) with acute myocardial infarction, the second one (14 patients) without previous ischemic episodes. Diagnostic accuracy, specificity and sensibility of the stress-echo test were evaluated in order to identify significant stenosis of the left anterior descending (LAD), right coronary (RCA), and/or circumflex artery (CA). Dobutamine stress echocardiography showed in all patients, from basal to peak, an increase in blood pressure (from 121.2 +/- 17.4 to 141.8 +/- 23.6 mmHg), heart rate (from 81.3 +/- 10.9 to 140.7 +/- 8.9 b/min), and double product (from 9861.1 +/- 1898.1 to 19976.6 +/- 3603.6). In 8 (32%) patients who had typical chest pain, 7 had CAD. In 17 (68%) patients without chest pain, 5 had CAD and 12 had normal coronary arteries. Dobutamine stress echocardiography showed segmental wall motion variations only in 13 patients; 12 of them had a significant stenosis of coronary artery relative to the ischemic area, the other 1 was a false positive. Coronary arteriography showed stenosis of LAD in 10 and of RCA and/or CA in 12 patients, in both groups dobutamine stress-echo test had 1 false negative. Dobutamine stress echocardiography showed high diagnostic value as a provocative non-invasive test for CAD in patients with left bundle branch block. In conclusion, or study shows that no statistical difference exists in identifying ischemia in identifying ischemia in the LAD territory compared to RCA and/or CA. Further investigations are need to confirm the higher diagnostic accuracy in patients with left bundle branch block and to establish whether lower specificity in patients with a previous myocardial infarction is due to the smaller number of patients or to methodology.
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PMID:[Stress echocardiography with dobutamine in the identification of coronary disease in patients with left bundle branch block]. 928 78

In animal experiments, dobutamine infusion was found to impair the oxygen supply-demand balance in hypoperfused areas of hibernating myocardium which may induce myocardial damage. The aim of our study was to assess whether dobutamine echocardiography can induce myocardial damage detected by an increase in the cardiac troponin T level in blood. Twenty seven patients with coronary artery disease and severe stenosis of at least one major coronary artery (> or = 90% of luminal diameter narrowing) supplying dysfunctional myocardial segments underwent dobutamine echocardiography. Dobutamine was infused in 3 min dose increments of 5, 10, 20, 30, and 40 microg per kg body weight per minute with the addition of atropine up to 1 mg if ischemia or an 85% predicted maximal heart rate were not achieved. In 15 patients the protocol with prolonged application of 40 microg per kg per minute of dobutamine for 6 min and for the next 5 min with the addition of atropine was used. To exclude minor myocardial damage, an increase in the cardiac troponin T blood level was assessed qualitatively by the TROP T sensitive Rapid Test 20 h after dobutamine echocardiography. In 20 patients the dysfunctional segments were found to be viable with inducible ischemia exhibiting either continuous worsening in systolic thickening or "biphasic" response characterised by the improvement of their systolic thickening with a small dose and by a worsening of the thickening with a high dose of dobutamine. No patient exhibited positive TROP T sensitive Rapid Test result. In patients with coronary artery disease and severe stenosis of a major coronary artery supplying dysfunctional but viable myocardial segments, dobutamine echocardiography does not induce myocardial damage detectable by an increase in cardiac troponin T level.
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PMID:Can dobutamine echocardiography induce myocardial damage in patients with dysfunctional but viable myocardium supplied by a severely stenotic coronary artery? 931 12


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