Frequency of false-positive septal defects on adenosine/201Tl images in patients with left bundle branch block

Comparison of myocardial contrast echocardiography with SPECT in the evaluation of coronary artery disease in asymptomatic patients with LBBB

“…The frequency of such false defects ranges in the literature from 10% to 80% and may relate to the patient population under study and the exercise protocol and endpoints used by the different authors [22]. Various mechanisms have been proposed to explain these false-positive myocardial perfusion defects.…”

“…At that time the outflow resistance is lower and, as a consequence of coronary autoregulation, perfusion is reduced [1]. However, we wish to specify that the mechanism by which false septal defects are created on scintigraphic images is currently a matter of speculation [22].…”

“…Adenosine thallium imaging is safe and has been proved superior to exercise thallium imaging in the detection of CAD in patients with LBBB, obviating septal artifacts (thereby markedly improving the specificity in the left anterior descending artery territory) [5]. In a large series, only 4% of the patients with LBBB had a false-positive reversible septal defect [22].…”

Adenosine Myocardial Perfusion Imaging

“…The predictive accuracy of exercise was 68% compared to 93% with adenosine. In a study of 900 patients who underwent adenosine thallium MPI [95], 68 patients had LBBB. Only 6 of the 68 patients had reversible septal defects on thallium imaging 3 of whom underwent coronary angiography and had significant LAD stenosis yielding at most a 4% incidence of false positive reversible septal defects with adenosine.…”

Comparative utility of gated myocardial perfusion imaging and transthoracic coronary flow reserve for the assessment of coronary artery disease in patients with left bundle branch block

“…Therefore, stress tests with non-inotropic agents, such as dipyridamole and adenosine, have been proposed as the procedures of choice for detecting CAD in patients with LBBB. Although false-positive (FP) results have been reduced by using this approach, about 20-30% of the cases still remain misclassified [3]. Regional wall motion changes and wall thickening have been considered responsible for septal perfusion abnormalities and FP findings on gated SPECT in patients with LBBB [4].…”