Myocardial perfusion gated single-photon emission computed tomography in patients with left bundle branch block: comparison between the end-diastolic images and the ungated images.
OBJECTIVE
Septal perfusion abnormalities are frequently observed in patients with left bundle branch block (LBBB). The aim of this study was to compare myocardial perfusion imaging obtained from ungated and diastolic thallium gated single-photon emission computed tomography (SPECT) images in patients with LBBB.


METHODS
Stress/rest SPECT was performed in 70 patients with LBBB [38 with coronary artery disease (CAD) (G1), 32 without (G2)] and 19 control participants (G3). Diastolic images were obtained as the sum of four diastolic bins. Perfusion was assessed by summed stress, rest, and difference scores for both diastolic and ungated images.


RESULTS
In G1, there was no difference between diastolic and ungated perfusion scores. In G2, summed stress score and summed rest score were increased in diastolic versus ungated imaging, and perfusion defect extent was increased on diastolic versus ungated images at stress (diastole: 6.2 +/- 9.9% vs. ungated: 5.1 +/- 9.70/%, P = 0.01) and rest (diastole: 4.3 +/- 9.3% vs. ungated: 2.8 +/- 9.50%, P = 0.0014), with an increased extent of reversible defect (diastole: 3.4 4.7% vs. ungated: 2.3 3.7%, P = 0.01). In G2, diastolic images failed to correct septal perfusion abnormalities. The number of normal SPECT did not increase with diastolic versus ungated imaging (24 and 180% in G1, 66 and 53% in G2, respectively). Otherwise, a significant association between left ventricular dysfunction and CAD was found, stress ejection fraction being decreased in 20 patients (53%) in G1 and seven patients (22%) in G2 (CHI2 = 6.93, P < 0.01).


CONCLUSIONS
In patients with LBBB, diastolic imaging did not provide additional information to ungated perfusion imaging, but left ventricular dysfunction was associated with CAD.
Edet-Sanson
Agathe
A
Department of Nuclear Medicine, Rouen University Hospital-Henri Becquerel Center, France.
Hitzel
Anne
A
Guernou
Mohamed
M
Véra
Pierre
P
Manrique
Alain
A
D002037:Bundle-Branch Block / Q000000981:diagnostic imaging* / Q000503:physiopathology*; D055426:Cardiac-Gated Single-Photon Emission Computer-Assisted Tomography / Q000379:methods*; D003971:Diastole; D005260:Female; D006352:Heart Ventricles / Q000000981:diagnostic imaging / Q000503:physiopathology; D006801:Humans; D008297:Male; D055414:Myocardial Perfusion Imaging / Q000379:methods*; D012189:Retrospective Studies