Morphology of myocardial bridging of right coronary artery: delineation using coronary computed tomography angiography

Objectives: To reveal the morphological features and follow-up outcome of right coronary artery myocardial bridging (RCA-MB) using coronary computed tomography angiography (CCTA). Methods: 37 consecutive patients with RCA-MB referred for CCTA were obtained. All subjects were divided into incomplete MB and complete MB groups according to the continuity of the myocardium over the tunneled segment of RCA. The length, Thickness, stenosis rate was evaluated. An individual follow-up study was executed to the subjects without coronary artery disease (CAD). Follow-up data were obtained from telephone contact and all available medical records in hospital. Results: Total 41 RCA-MB were detected (complete type, 63.4%). 60.9% (25/41) occurred in mid segment of RCA. 73% (30/41) occurred in right atrium and 68.3% (28/41) coexisted with MB in other segment. The mean length, thickness and stenosis rate were 11.7 +/- 7.5 mm, 1.8 +/- 0.3 mm and 29 +/- 10.8% respectively. 21 patients finished the follow-up study with 2 positive readmitting subjects. There was no significant difference in clinical symptoms and objective signs of ischemia between controls and patients with RCA-MB. Conclusions: Although it did not increase prevalence of myocardial ischemia statistically, RCA-MB still could induce clinical symptoms by chance and should be paying attention in daily reconstructing workflow.