A case report of a coronary myocardial bridge with impaired full-cycle ratio during dobutamine challenge.

Optical coherence tomography may contribute to anatomical detections of MBs. Because a systolic compression of the MB and release of the vascular lumen during early diastole leads to an early steep pressure loss, early diastolic Pd drop should be one of the specific haemodynamic characteristics of MBs. On the other hand, in a severe atherosclerotic stenosis, Pd drop is typically observed in late diastole, which could be differentiated from that of MBs. Because full-cycle ratio reflects the whole cardiac cycle including early diastole, this might be more useful than other physiological indices for detection of MB-related ischaemia induced by a dobutamine challenge.