Clinical value of the correlations of mural coronary artery compression extent with myocardial bridge length and thickness evaluated by 128-slice CT

This study aimed to investigate the correlations between the detection rate of mural coronary artery (MCA) by 128-slice CT and the MCA compression extent in systole with myocardial bridge (MB) length and thickness. A retrospective analysis was conducted for 580 patients receiving multislic-espiral CT coronary angiography (MSCTCA). In addition, the MCA incidence rate and position were detected, and the MB length and thickness in the left anterior descending branch (LAD) and MCA compression extent in systole were measured to compare the differences between MB-MCA length and thickness among the mild, moderate and severe groups. A total of 140 cases of MB-MCA (24.14%) were involved in the study. Among them, 104 cases occurred in the middle segment of the LAD (74.3%), 16 cases (11.4%) occurred in the distal segment of the LAD, 8 cases (5.7%) occurred in the left circumflex-obtuse marginal branch (LCX-OM),7 cases (5.0%) occurred in the first diagonal branch (1st D), 3 cases (2.1%) in the intermediate branch (M) and 2 cases (1.5%) occurred in the posterior descending branch of the right coronary artery (RCA-PD). The mean length of the MB in the LAD was 21.80 +/- 5.98 mm, the mean thickness was 2.15 +/- 0.74 mm and the mean compression extent was 38.5 +/- 19.6%. Among the different groups, there were no significant difference in MB length (P>0.05) but there were significant differences in MB thickness (P<0.05). In addition, the extent of MCA compression in systole was linearly and positively correlated with MB thickness (r=0.408, P<0.05) but was not correlated with MB length (r=0.076, P>0.05). 128-slice CT coronary angiography (SCTCA) is able to accurately detect MB-MCA and evaluate the correlations of MCA compression extent in systole with MB length and thickness which provides a basis for its clinical use.