99mTc-MIBI stress-rest myocardial perfusion scintigraphy in patients with complete left bundle branch block

Abstract
Background. Patients with complete left bundle branch block (LBBB) often show a false-positive ischaemic pattern in the interventricular septum on thallium-201 (201Tl) stress-rest myocardial perfusion scintigraphy. Equivocal results have been reported with technetium-99m labelled hexakis-methoxyisobutyl isonitrile (99mTc-MIBI) in such patients. The aim of this retrospective study was to determine the effect of LBBB on the septal uptake of 99mTc-MIBI during stress-rest single photon emission computed tomography (SPECT) scintigraphy. Methods. We studied 75 consecutive patients with LBBB, referred for 99mTc-MIBI stress-rest SPECT. Studies were evaluated by visual analysis using a semi-quantitative grading technique. In all patients with abnormal septal segments, the presence or absence of ischaemic heart disease was confirmed either clinically or by means of angiographical examination. Results. Forty-three patients (57.3%) had completely normal studies. Only 15 (20%) had septal abnormalities (11 with reversible and 4 with fixed defects), while 17 patients (22.7%) had abnormal segments in areas other than the interventricular septum. Except for 1 patient lost to follow-up, ischaemic heart disease was confirmed in all the patients with septal changes. Conclusion. We conclude that 99mTc-MIBI is more specific than 201Tl for identifying ischaemic heart disease in the presence of LBBB.
Description
CITATION: Ellmann, A. et al. 2001. 99mTc-MIBI stress-rest myocardial perfusion scintigraphy in patients with complete left bundle branch block. Cardiovascular Journal of Africa, 12(5).
Keywords
methoxy isobutyl isonitrile technetium tc 99m
Citation
Ellmann, A. et al. 2001. 99mTc-MIBI stress-rest myocardial perfusion scintigraphy in patients with complete left bundle branch block. Cardiovascular Journal of Africa, 12(5).
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