Angiographic view (LAO 32°/16° cranial) of the left coronary artery reveals left main stem stenosis (arrow, B). During this short angiographic run, there were only a few frames with sufficient amount of contrast dye in the left main stem. In these frames, there was no contrast in the left anterior descending artery, the left circumflex artery did not disclose stenoses. The whole angiographic series is shown as a movie in the Additional file 1 