Gated spect myocardial perfusion scintigraphy for identifying septal perfusion artifacts in left bundle branch block.
OBJECTIVE
To determine the role of gated Single Photon Emission Computed Tomography (SPECT) for accurate assessment of myocardial perfusion scintigraphy (MPS) of patients with left bundle branch block (LBBB).


METHODS
Analytical study.


METHODS
Punjab Institute of Nuclear Medicine (PINUM), Faisalabad, Pakistan, from June 2002 to April 2003.


METHODS
MPS data of patients with LBBB was analyzed. Resting gated SPECT MPS was performed after an injection of 740 MBq 99mTc-MIBI in 10 normal and 25 subjects with LBBB (with low probability of coronary artery disease). Visual and quantitative analyses were done on non-gated (NG), end diastolic (ED), end systolic (ES) images. Calculations included septal to lateral wall ratio (SLR), myocardial thickening (MT=% increase in counts during systole) at end systolic phase and myocardial thickening at peak level (% peak MT).


RESULTS
Septal hypoperfusion was noted in 19 (76%) patients on NG images and in only 1 (4%) patient on gated SPECT ED images. On NG images of LBBB group, SLR was lower than in controls (0.68+/-0.07 vs. 0.87+/-0.05, p<0.001). SLR of LBBB patients approached to that of control group in gated SPECT ED data (0.86+/-0.06 vs 0.88+/-0.06, p=ns). Myocardial thickening at ES for septum was markedly lower in LBBB group than in controls (21.83%+/-10.86 vs. 66.32%+/-20.15, p<0.001).


CONCLUSIONS
In patients with LBBB, reduced septal thickening results in artifactual septal perfusion defects. Gating the perfusion scintigraphy and reporting perfusion status on end diastolic frames in LBBB patients can eliminate these artifacts.
Afzal
Muhammad Shehzad
MS
Department of Nuclear Cardiology, Punjab Institute of Nuclear Medicine, Adjacent Allied Hospital, Faisalabad, Pakistan. pinum@fsd.comsats.net.pk
Imran
Muhammad Babar
MB
Aslam
Naeem
N
Khurshid
Syed Javaid
SJ
Khan
Muhammad Aleem
MA
Irfan
Javaid
J
Farooq
Umer-I-
UI
Shoaib
Muhammad
M
Akhtar
M Saeed
MS
Muhammad
Khan
K
Nadeem
Afzal
A
D000328:Adult; D000368:Aged; D016477:Artifacts; D002037:Bundle-Branch Block / Q000000981:diagnostic imaging* / Q000473:pathology; D016022:Case-Control Studies; D003324:Coronary Artery Disease / Q000000981:diagnostic imaging; D005260:Female; D015637:Gated Blood-Pool Imaging; D006346:Heart Septum / Q000000981:diagnostic imaging* / Q000473:pathology* / Q000503:physiopathology; D006801:Humans; D008297:Male; D008875:Middle Aged; D009200:Myocardial Contraction; D015425:Myocardial Reperfusion; D009206:Myocardium / Q000473:pathology; D010154:Pakistan; D019275:Radiopharmaceuticals; D017256:Technetium Tc 99m Sestamibi; D015899:Tomography, Emission-Computed, Single-Photon
D019275:Radiopharmaceuticals; D017256:Technetium Tc 99m Sestamibi