High accuracy of myocardial perfusion imaging in patients with left bundle branch block: comparison of four interpretation approaches.
Although myocardial perfusion imaging (MPI) with pharmacologic stress is the standard method for screening coronary artery disease (CAD) in patients with left bundle branch block (LBBB), controversies remain about its correct interpretation. We sought the best interpretation approach in these patients to achieve higher accuracy. Forty-two patients with LBBB underwent MPI with dipyridamole stress and the criteria for positive results with four patterns of interpretation were as follows: Pattern A: any reversible or irreversible perfusion abnormality in the myocardium irrespective of the location or extension was considered positive. Pattern B: any reversible or irreversible perfusion abnormalities except in the septal/anteroseptal region were defined as positive. Pattern C: in the absence of fixed LV cavity dilatation, the scan was interpreted the same as pattern A, while in the presence of fixed LV cavity dilatation, only the abnormalities outside the LAD territory was defined as positive. Pattern D: as in pattern C, except that in the absence of fixed LV cavity dilatation, the scan was read according to pattern B. For all patients, the angiographic results were considered as gold standard of CAD diagnosis. Our results showed that the false positive rate of MPI in patients with fixed LV dilatation was 50%, while in cases with normal LV size or transient dilatation, was 38.5%. This difference was more prominent in the female patients. The accuracy for screening CAD for patterns A, B, C and D were 57%, 62%, 69% and 69%, respectively. Pattern D was the better approach in female cases and patients with fixed septal/anteroseptal defects. In conclusion, a) in the male population without fixed defects in the septal/anteroseptal region, the specificity and accuracy are high in all patterns and the pattern of reading does not significantly influence the diagnostic value of MPI for CAD screening. b) in LBBB patients, fixed defects limited to the septal/anteroseptal region should be considered a significant finding only when LV cavity is not dilated.
Fallahi
Babak
B
Research Institute for Nuclear Medicine, Shariati Hospital, Tehran, Iran.
Beiki
Davood
D
Eftekhari
Mohammad
M
Gilani
Kianoush Ansari
KA
Fard-Esfahani
Armaghan
A
Gholamrezanezhad
Ali
A
Sharif
Ahmad Yamini
AY
Ansari
Mojtaba
M
Saghari
Mohsen
M
D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D000465:Algorithms; D002037:Bundle-Branch Block / Q000150:complications / Q000000981:diagnostic imaging*; D005260:Female; D006801:Humans; D007089:Image Enhancement / Q000379:methods; D007090:Image Interpretation, Computer-Assisted / Q000379:methods*; D008297:Male; D008875:Middle Aged; D055420:Perfusion Imaging / Q000379:methods*; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity; D018487:Ventricular Dysfunction, Left / Q000000981:diagnostic imaging* / Q000209:etiology