Coronary flow abnormalities with myocardial bridging

The contrasting patterns of variation in vessel area (VA) and coronary flow velocity (CFV) in a normal vessel (N) and in a muscle bridge segment (B). The end of the QRS (black line) represents the start of isometric contraction of the left ventricle and point of opening of aortic valve and the end of the T-wave (red line) represents the end of systole and the point of closure of aortic valve. In the bridged segment, vessel area falls markedly during systole and increases during diastole with a marked early peak in diastolic coronary flow velocity (arrow).