title: False-positive reversible perfusion defect during dobutamine-thallium imaging in left bundle branch block.
abstract: In the presence of pre-existing left bundle branch block (LBBB) exercise stress thallium scans have been associated with false-positive septal and apical perfusion abnormalities. Recent reports have documented a lower incidence of false-positive septal perfusion defects when pharmacologic agents such as dipyridamole or adenosine are utilized in patients with LBBB. Dobutamine, a synthetic catecholamine, is being used with increasing frequency in combination with perfusion agents for the diagnosis of coronary artery disease in patients unable to achieve an adequate exercise workload. Because the positive inotropic and chronotropic actions of doubtamine are similar to the physiologic effects of treadmill exercise, it is conceivable that false-positive perfusion abnormalities will be observed in patients with pre-existing LBBB undergoing dobutamine perfusion imaging. We describe a patient with underlying LBBB who underwent dobutamine thallium imaging which revealed septal and periapical defects. Subsequent coronary angiography showed these abnormalities to be false-positive. It is concluded that septal and periapical perfusion abnormalities during dobutamine thallium imaging may be false-positive and should be interpreted cautiously.
authors.affiliation: Division of Cardiology, Jefferson Medical College, Thomas Jefferson University, Philadelphia.
authors.forename: D A
authors.initials: DA
authors.lastname: Tighe
authors.forename: H G
authors.initials: HG
authors.lastname: Hutchinson
authors.forename: C H
authors.initials: CH
authors.lastname: Park
authors.forename: E K
authors.initials: EK
authors.lastname: Chung
authors.forename: D L
authors.initials: DL
authors.lastname: Fischman
authors.forename: J S
authors.initials: JS
authors.lastname: Raichlen
mesh_terms: D002037:Bundle-Branch Block / Q000000981:diagnostic imaging*; D002637:Chest Pain; D017023:Coronary Angiography; D003331:Coronary Vessels / Q000000981:diagnostic imaging; D004280:Dobutamine; D004562:Electrocardiography; D005080:Exercise Test; D005189:False Positive Reactions; D006801:Humans; D008297:Male; D008875:Middle Aged; D010477:Perfusion; D011877:Radionuclide Imaging; D013794:Thallium Radioisotopes
chemical_list: D013794:Thallium Radioisotopes; D004280:Dobutamine