Detection of severe stenosis and total occlusion in the left anterior descending coronary artery with transthoracic Doppler echocardiography in the emergency room.

Background: The noninvasive measurement of coronary flow velocity in the left anterior descending artery (LAD) has recently been realized by using the transthoracic Doppler echocardiography (TTDE). A couple of investigations demonstrated that the diastolic-to-systolic peak velocity ratio (DSVR) by TTDE is a simple and noninvasive method for the detection of severe stenosis in the elective settings. However, the usefulness of DSVR by TTDE in the emergency settings has not been evaluated. Objective: The purpose of this study was to assess the clinical feasibility to document the LAD flow by TTDE in emergency patients who complained of chest pain. Methods: We studied 49 consecutive patients with acute coronary syndrome who were going to undergo emergency coronary angiography (CAG) for the anatomical diagnosis and the facilitated percutaneous coronary intervention (PCI). Prior to CAG, we recorded the LAD flow by TTDE and measured the diastolic peak velocity (DVp), systolic peak velocity (SVp), and their ratio, DSVR (DVp/SVp) of LAD flow. Results: By CAG, the culprit lesions actually resided in the proximal LAD in 36 patients. Among the 36 patients, we detected the Doppler LAD flow in 29. Five out of 7 patients who were unable to detect the LAD flow revealed total occlusions by CAG. DSVR of the LAD is significantly lower in 17 patients who showed severe stenoses (>90%) than those in the rest of 12 patients who did not show such critical stenoses (1.44 ± 0.16 vs 2.10 ± 0.26, P < 0.0001). Conclusion: In the emergency settings, a noninvasive assessment of the LAD flow by TTDE accurately estimates the critical stenotic lesions of the LAD.