title: Abnormal nondefect zone myocardial thallium washout ratio in patients with reversible thallium defects and normal coronary arteriograms.
abstract: Thallium myocardial defects in patients with no angiographic coronary artery stenosis have been attributed to attenuation effects and other artifacts. Of 323 patients having thallium myocardial imaging following dipyridamole infusion, 10 of 159 patients with a segmental perfusion abnormality were found to have no luminal diameter stenosis greater than 20% on coronary angiography and no electrocardiographic (ECG) evidence of myocardial infarction or left bundle branch block. A time-standardized regional thallium washout ratio was calculated as thallium myocardial counts with dipyridamole to counts without dipyridamole. In comparison to 10 age-matched control patients with no evidence of cardiac disease and no myocardial thallium defect, study patients had a lower regional myocardial thallium washout ratio from both the defect and nondefect (1.57 +/- 0.40 versus 2.27 +/- 0.92, p = 0.041) zones. Nine of the 10 study patients had independent evidence of noncoronary heart disease, including echocardiographic or ECG evidence of left ventricular hypertrophy in six patients. In patients with thallium defects and normal coronary arteriograms, a time-standardized regional thallium myocardial washout ratio for the nondefect zone may aid in the differentiation of patients with noncoronary heart disease from those with soft tissue artifacts.
authors.affiliation: Department of Internal Medicine, University of Cincinnati, OH 45267-0542.
authors.forename: M C
authors.initials: MC
authors.lastname: Gerson
authors.forename: H
authors.initials: H
authors.lastname: Smith
authors.forename: P
authors.initials: P
authors.lastname: Carr
mesh_terms: D016477:Artifacts; D017023:Coronary Angiography; D003327:Coronary Disease / Q000000981:diagnostic imaging; D003937:Diagnosis, Differential; D004176:Dipyridamole; D004452:Echocardiography; D004562:Electrocardiography; D005260:Female; D006321:Heart / Q000000981:diagnostic imaging*; D006331:Heart Diseases / Q000000981:diagnostic imaging*; D006801:Humans; D008297:Male; D008875:Middle Aged; D011877:Radionuclide Imaging; D013794:Thallium Radioisotopes
chemical_list: D013794:Thallium Radioisotopes; D004176:Dipyridamole