Exercise thallium-201 imaging in complete left bundle branch block and the prevalence of septal perfusion defects.
To determine the prevalence of septal defects in a generalized referral population, the records of 93 consecutive patients with complete left bundle branch block (BBB) who underwent symptom-limited treadmill exercise testing with thallium-201 myocardial imaging over a 3-year period were reviewed. Segmental analysis of the planar thallium-201 images was performed in a blinded fashion with agreement by consensus. Computerized quantitative analysis of the images also was independently performed, and was correlated with the visual interpretations. Forty-seven patients (51%) had normal images, and 46 (49%) had defects of greater than or equal to 2 segments. In the abnormal studies, only 13 patients (14% of the total population) had septal defects, while a much higher number of patients, 33 (39%), had inferior or apical defects, or both. Coronary angiography was performed in 6 patients with septal defects: Significant narrowing of the left anterior descending coronary artery was found in 4 patients, a narrowed right coronary artery was found in 1, and normal coronary arteries were seen in the other patient. In conclusion, whereas previous studies have suggested a high percentage of false-positive septal defects in patients with left BBB, this study demonstrates a low prevalence (14%) of septal defects in a large population of unselected patients presenting for exercise thallium-201 imaging. Therefore, exercise thallium-201 imaging remains a useful procedure for evaluating patients with complete left BBB.
Jazmati
B
B
Department of Medicine, Memorial Hospital of Rhode Island, Pawtucket 02860.
Sadaniantz
A
A
Emaus
S P
SP
Heller
G V
GV
D000368:Aged; D002037:Bundle-Branch Block / Q000000981:diagnostic imaging*; D009202:Cardiomyopathies / Q000000981:diagnostic imaging / Q000453:epidemiology; D004562:Electrocardiography; D005080:Exercise Test; D005189:False Positive Reactions; D005260:Female; D006346:Heart Septum / Q000000981:diagnostic imaging* / Q000503:physiopathology; D006801:Humans; D008297:Male; D015995:Prevalence; D011877:Radionuclide Imaging; D013794:Thallium Radioisotopes
D013794:Thallium Radioisotopes