Figure 1

A 65 year old lady had LBBB on her ECG but normal coronary arteries on X-ray coronary angiography. A myocardial blood flow (MBF) map generated from quantitative perfusion CMR data at stress demonstrates a relative but not absolute reduction in septal perfusion (arrow, septal stress MBF = 2.76 ml/g/min) compared to the lateral region (lateral stress MBF= 3.74 ml/g/min).