Characteristic coronary flow pattern of left anterior descending stenosis by transthoracic echocardiography

Coronary flow reserve (CFR) as detected by echocardiography correlate well with the angiographic degree of coronary stenosis whether significant or not. However, value of resting coronary flow velocities (CFV) and its pattern in predicting coronary artery disease (CAD) severity is not studied enough. The present study aimed to assess CFV and pattern of distal left anterior descending (LAD) artery of different stenosis using transthoracic echocardiography (TTE) to elucidate the possible association. CFV and CF pattern were measured in distal LAD by TTE in 97 patients who were subjected for coronary angiography (CA) at our department for suspected CAD and were found to have LAD stenosis of different severity during the period from November 2011 to December 2012. Peak systolic velocity (PFVS), peak diastolic velocity (PFVD), average velocity (VA) and diastolic deceleration time (DDT) were obtained. The patients were enrolled in three groups, group I included 30 patients with normal CA, group II included 34 patients with LAD stenosis 50–69% and group III included 33 patients with LAD stenosis ≥70%. There was no significant difference between the studied groups regarding age and gender. There was no significant difference between the studied groups regarding PFVS, PFVD and VA (p > 0.05). While DDT showed significant shortening in group III (580 ± 19.3 ms) versus 800.7 ± 6.4 ms in group I and 750 ± 34.7 ms in group II (p = 0.001). A receiver-operating characteristic-derived DDT cut point ≤655 ms was 100% specific and 100% sensitive for detecting severe LAD stenosis (>70%). In patients with suspected CAD, short DDT of distal LAD flow as detected by TTE can effectively detect severe LAD stenosis.