False positive pharmacologic myocardial perfusion SPECT study in the setting of a left bundle branch block.

We herein report a case of a false positive vasodilatory pharmacologic SPECT stress test in the setting of a left bundle branch block (LBBB). While this is more commonly seen with exercise stress testing, it can also occur with pharmacologic stress testing. In our SPECT exam, we illustrate the commonly mistaken septal/anteroseptal perfusion defects in those patients with a LBBB. PET stress testing may be more reliable for patients with LBBB.