Multislice computed tomographic patterns of muscle bridging of left anterior descending artery and their relation to atheromatous coronary artery disease

ABSTRACT

To determine the frequency of atheromatous coronary artery disease in patients with myocardial bridge. Descriptive study. AFIC/NIHD Rawalpindi from September 2010 to November 2010. Patients undergoing MSCT angiography for diagnosis of CAD having an abnormal finding were included. Patients with history of prior coronary artery bypass grafting [CABG], coronary stenting and with chronic total occlusions were excluded. Computed Tomographic [CT] examinations were performed with a dual-source CT scanner. Scanning parameters detector collimation, 2 x 32 x 0.6 mm; slice collimation, 2 x 64 x 0.6 mm; gantry rotation time, 330 milliseconds; tube current-time product, 350 mAs per rotation and tube potential 120 kV. Reconstructions done and data transmitted to workstations and analyzed. Myocardial bridge [MB] was diagnosed and evaluated when an intramuscular segment of LAD artery was visualized on axial, volume rendered and multiplanar reformation [MPR] images. Out of 232 patients 32% had MB. Males were three times more likely to have Myocardial bridge [MB]. Mid and distal LAD showed 54% and 45% MBs respectively. Fourteen percent had evidence of atherosclerosis proximal to MB segment. Mean length and depth of MB segment was 18mm and 1.8mm respectively. Superficial type was most common [44%], followed by deep type [33%] while RV type was least common [23%].Frequency of patients with myocardial bridge having concomitant atheromatous coronary artery disease was 14%