Left ventricular responses to dopamine in dilated cardiomyopathy as assessed by two-dimensional echocardiography and compared with findings of thallium-201 scintigraphy.
The effects of dopamine on the left ventricular regional wall motion were studied in 11 patients with dilated cardiomyopathy by use of two-dimentional echocardiography and compared with the findings on the uptake of thallium-201. There were no significant changes in heart rate after dopamine infusion (6 micrograms/kg/min). However, the administration of dopamine significantly reduced PEP/ET and increased the systolic blood pressure, fractional shortening, ejection fraction and mVcf. The percentage of segments with reduced thallium-uptake area was significantly higher in abnormal wall motion segments than in normal wall segments both before and after dopamine administration. The percentage of segments with reduced thallium-uptake area was significantly higher in abnormal wall motion segments after loading than in normal wall segments before loading or in dopamine responding segments. However, in reduced uptake area, the asynergy of the left ventricle was improved significantly after dopamine administration. These results demonstrated that the abnormality of Tl-uptake was correlated roughly to the asynergy of the left ventricle, but that the state of remaining myocardium was not necessarily evaluated correctly by Tl-uptake. Dopamine loading seemed to be useful for more accurate evaluation of myocardial residual function.
First Department of Internal Medicine, Niigata University School of Medicine, Japan.
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Oda
D002311:Cardiomyopathy, Dilated / Q000000981:diagnostic imaging / Q000503:physiopathology*; D004298:Dopamine; D004452:Echocardiography; D006352:Heart Ventricles / Q000000981:diagnostic imaging; D006439:Hemodynamics / Q000187:drug effects; D006801:Humans; D009200:Myocardial Contraction / Q000187:drug effects*; D011877:Radionuclide Imaging; D013794:Thallium Radioisotopes
D013794:Thallium Radioisotopes; D004298:Dopamine