Dose Dobutamine Echocardiography Research Articles

Head-to-Head Comparison of Exercise–Redistribution–Reinjection Thallium Single-Photon Emission Computed Tomography and Low Dose Dobutamine Echocardiography for Prediction of Reversibility of Chronic Left Ventricular Ischemic Dysfunction

Head-to-Head Comparison of Exercise–Redistribution–Reinjection Thallium Single-Photon Emission Computed Tomography and Low Dose Dobutamine Echocardiography for Prediction of Reversibility of Chronic Left Ventricular Ischemic Dysfunction

Stunned myocardium after thrombolytic treatment. Identification by dobutamine echocardiography and role of the residual stenosis in the infarction artery

The aim of this study was to identify post-thrombolysis stunned myocardium using low dose (10 μg/kg/min) dobutamine echocardiography, and to elucidate the role of the residual stenosis in the infarction artery in wall motion recovery. Forty-seven consecutive patients treated with thrombolytic agents for a first non-complicated myocardial infarction were included. An early dobutamine echocardiogram was performed 7 ± 2 days after thrombolysis to calculate a wall motion score index at baseline and with dobutamine. A late resting echocardiogram 36 ± 7 days and a coronariography 41 ± 8 days after thrombolysis were also performed. In 12 patients no baseline regional dysfunction was observed in the early echocardiogram (Group I), whereas 35 patients (Group II) presented regional dysfunction which improved with dobutamine in 11 cases (Group IIA), but not in 24 (Group IIB). Maximum creatine kinase peak was smaller in Group I (458 ± 162, P ≤ 0.01) and in Group IIA (931 ± 593, P ≤ 0.05) than in Group IIB (1547 ± 886). Late resting echocardiogram was performed in 44 patients: all 12 from Group I, 10 from Group IIA and 22 from Group IIB; all patients from Group I persisted with normal wall motion, while the baseline score index improved in seven patients (70%) from Group IIA vs. three patients (14%) from Group IIB ( P ≤ 0.01). Quantitative angiographic parameters in the infarction artery failed to differentiate the subgroup of patients in whom wall motion improved in the late echocardiogram. By simple regression, smaller creatine kinase peak ( P ≤ 0.05) and a positive response to dobutamine in the early echocardiogram ( P ≤ 0.001) correlated with wall motion recovery, but the minimum lumen diameter in the infarction artery did not correlate; by multiple logistic regression, only a positive response to dobutamine in the early echocardiogram independently predicted late wall motion improvement ( P ≤ 0.001). Conclusions: (1) Low dose dobutamine echocardiography early after thrombolytic treatment identifies dysfunctional myocardium with potential late spontaneous improvement (stunned myocardium). (2) Myocardial stunning tends to occur in small infarctions. (3) Late wall motion improvement can occur despite severe residual stenosis in the infarction artery.

Enhanced detection of myocardial ischemia by stress dobutamine echocardiography utilizing the “biphasic” response of wall thickening during low and high dose dobutamine infusion

We sought to assess the ability of the "biphasic" response (i.e., initial improvement in wall thickening followed by reduced wall thickening) during serial dobutamine stress echocardiography to detect ischemia in patients with a wall motion abnormality. Furthermore, we compared the power of the biphasic echocardiographic response with that of myocardial perfusion imaging for the detection of myocardial ischemia. Stress echocardiography has been shown to be less sensitive than radionuclide perfusion imaging for detecting ischemia in patients with a wall motion abnormality. Peak stress wall thickening in such areas may not give a full account of the intermediate changes, whereas initial improvement (the biphasic response) may enhance diagnosis. Patients with a wall motion abnormality and documented coronary artery disease underwent simultaneous graded dobutamine (5 to 40 micrograms/kg body weight per min) stress echocardiography and radionuclide perfusion imaging with single-photon emission computed tomography using either technetium-99m sestamibi or technetium-99m tetrofosmin. Semiquantitative analyses of image groups were performed in blinded manner by two separate groups of observers. Myocardial ischemia was detected by perfusion imaging in 45 of the 54 patients. High dose dobutamine echocardiography detected ischemia in only 25 (56%) of these patients. However, when the biphasic response was taken into account, ischemia was detected in 44 (98%) of the 45 patients (p < 0.001). Agreement between radionuclide imaging and echocardiographic findings for the detection of ischemia was significantly enhanced (p = 0.03) when the biphasic response was used (89%, kappa = 0.51) instead of high dose stress dobutamine echocardiography (56%, kappa = 0.10). The detection of myocardial ischemia may be significantly enhanced by utilizing the biphasic response during serial stress dobutamine echocardiography in patients with a wall motion abnormality.

Low dose dobutamine echocardiography, thallium scintigraphy and 18-fluorodeoxglucose positron emission tomography for detection of myocardial viability in chronic coronary artery disease

Low dose dobutamine echocardiography, thallium scintigraphy and 18-fluorodeoxglucose positron emission tomography for detection of myocardial viability in chronic coronary artery disease

722-5 Dobutamine Echocardiography and Rest SPECT TI·201 Scintigraphy are More Concordant in Detecting Viability in Hibernating than Stunned Myocardium

Perfusion and function are mismatched in stunned myocardium and matched in hibernating myocardium. To determine the relationship between perfusion and functional impairment, 82 patients with stunned myocardium (left ventricular [LV] dysfunction after acute myocardial infarction [MI], 59 ± 13 yrs.) and 16 patients with hibernating myocardium (chronic LV dysfunction due to multivessel coronary disease, 60 ± 15 yrs.) underwent low dose dobutamine echocardiography (DE) and rest SPECT TI-201 (3 mCi, 3 hr. imaging) scintigraphy. Both studies were analyzed according to the standard 16 segment model and 4 point scoring systems. Nonviability was defined as akinesis unresponsive to dobutamine (DE) or severely reduced uptake (TI-201) in ≥ 4 segments of a vascular territory. Concordance (%) was analyzed in 736 segments (351 normal [N] or hypokinetic [H] and 385 akinetic [A]) from the 82 patients with acute MI and 256 segments (120 N or Hand 136 A) from the 16 patients with chronic dysfunction. Acute Chronic TI-201 Viable + + – – + + – – DE Viable + – + – + – + – Total Seg 59 10 11 * 20 63 14 2 21 N or H Seg 92 * 0 8 * 99 0 1 0 A Seg 29 20 13 * 38 30 27 4 39 Patients 47 * 12 12 * 29 59 6 0 35 * p &lt; 0.05 vs chronic concordance of DE and TI-201 scintigraphy is very high in hibernating and reduced in stunned myocardium indicative of the effects of matched and mismatched perfusion and function.

1010-122 Stress-Rest Dobutamine SPECT Tc-99m Sestamibi Accurately Predicts Myocardial Viability in Dysynergic Left Ventricular Segments

There has been increasing controversy regarding the ability of SPECT Tc99m Sestamibi (MIBI) for identification of myocardial viability in regions of the left ventricle affected by severe wall motion abnormality. We have evaluated 27 patients with documented coronary artery disease (CAD) and severe regional wall motion abnormality of the left ventricle due to CAD. All patients underwent low dose (5–10 μ g/kg) dobutamine echocardiography and maximal (15–40 μ glkg/min) stress dobutamine MIBI. A separate day SPECT MIBI was performed at rest. The left ventricle was divided into 3 regions; a total of 37 regions were found to have severe wall motion abnormality by echocardiography, of which 35 showed improved wall thickening with low dose dobutamine (gold standard for myocardial viability in this study). Rest MIBI uptake was assessed semiquantitatively for each of the matching regions, and this was graded from 1 to 4, from normal to absent perfusion. Regions with myocardial perfusion of a grade of 3 or less were considered viable by rest MIBI. Rest MIBI detected viability in 32 (93%) of the viable regions, as defined by echocardiography, the concordance was 92% (kappa = 0.54, P &lt; 0.001). Furthermore, stress-rest MIBI revealed completely reversible defects in 18 (23%), partially reversible defects in 24 (69%) and Grade 4 uptake and fixed (non-viable) defects in 3 (8%) regions defined as viable by dobutamine echocardiography. Thus, rest MIBI is a good indicator of myocardial viability in left ventricular segments showing severe regional dysynergy, and reversible ischaemia detected by stress-rest dobutamine MIBI in these segments provides further proof that sestamibi SPECT accurately defines regional myocardial viability.

905-57 Viability by Dobutamine Echocardiography Identifies Patients Whose Outcome is Improved by Elective Revascularization After Acute Myocardial Infarction

Patients with viable myocardium and residual stenosis after acute myocardial infarction (MI) may benefit from elective early revascularization. To determine whether echocardiographic viability identifies the patients whose outcome is improved by elective early revascularization, 140 patients (age 57 ± 13 yrs, 116 males, 24 females) underwent low dose dobutamine echocardiography (5-10 μg/kg/min) at 5 ± 2 days after acute MI and were followed for &gt; 1 year. Sixty-three patients had anterior infarction and 97 were treated with thrombolytic therapy. Sixty-one patients were electively revascularized (50 angioplasty, 11 bypass surgery). Echocardiographic images were analyzed according to the standard 16 segment model and viability defined as akinesis unresponsive to dobutamine in ≥ 3 infarction zone segments. Eighty-four patients were identified as viable. Clinical, echocardiographic and angiographic data were similar in revascularized and nonrevascularized patients. Adverse outcome occurred in 52/140 patients (cardiac death 6, nonfatal MI 9, sustained ventricular tachycardia 3, heart failure 8, unstable angina 26). The incidence of adverse outcome in our four groups was as follows: Revascularized Medical Viable 10% (4/391 * 27% (12/45) Nonviable 77% (17/22) † 56% (19/34) ‡ * p = 0.05 vs medical † p &lt; 0.001 vs viable ‡ p &lt; 0.05 vs viable In conclusion, adverse outcome was significantly greater (p &lt; 0.001) in patients with echocardiographic nonviability. Revascularization improved clinical outcome only in patients with viable myocardium identified with dobutamine stress echocardiography.

Exercise and rest Tl-201 myocardial SPECT, and low dose dobutamine echocardiography to assess myocardial viability in patients with myocardial infarction

Exercise and rest Tl-201 myocardial SPECT, and low dose dobutamine echocardiography to assess myocardial viability in patients with myocardial infarction

30. Synergistic value of low dose dobutamine echocardiography and 201Tl imaging in the detection of viable myocardium in patients with chronic ischaemic cardiomyopathy

30. Synergistic value of low dose dobutamine echocardiography and 201Tl imaging in the detection of viable myocardium in patients with chronic ischaemic cardiomyopathy