Value of transthoracic Doppler echocardiography in the assessment of the left anterior descending artery flow in patients follow acute myocardial infarction

BackgroundThe primary goal in the management of acute myocardial infarction is to institute reperfusion as early as possible. A major problem facing cardiologists lies in the limitation of accurate identification of patients in whom antegrade coronary flow has not been restored, whether spontaneously or following thrombolytic therapy. Clinical markers of reperfusion, such as relief of ischemic-type of chest discomfort, resolution of the ST-segment elevation, and the occurrence of reperfusion arrhythmias have limited predictive value in identifying failure of thrombolysis.ObjectivesAssessment of reperfusion by direct visualization of the distal left anterior descending artery (LAD) flow using transthoracic Doppler echocardiography (TTDE) with 2.5MHz probe, making assessment of reperfusion bedside, simple and reliable tool.MethodsWe prospectively studied 74 consecutive patients who underwent coronary angiography following an acute ST-segment elevation myocardial infarction. We performed for all of them TTDE with assessment of the LAD distal flow by color Doppler.ResultsUsing TTDE, it was possible to visualize the distal LAD flow in 49 among 60 patients with angiographically patent LAD. Occluded LAD was detected in 9 among 14 patients with angiographically occluded LAD. The sensitivity, specificity, positive predictive value, negative predictive value and accuracy of the transthoracic Doppler echocardiography in the noninvasive assessment of the left anterior descending artery reperfusion with 2.5MHz transducer were 81.6%, 64%, 90.7%, 54% and 78% respectively. Detection of the distal left anterior descending artery flow by TTDE was significantly correlated with the reperfusion of the left anterior descending artery as assessed by coronary angiography (P=0.001).ConclusionsUnlike the widely used noninvasive methods (ECG changes, resolution of ischemic-type of chest pain and characteristic pattern of rise and decline of cardiac markers) for assessment of reperfusion following anterior myocardial infarction, the use of TTDE can be used as more reliable, simple, noninvasive, and widely available tool for direct visualization of the LAD distal flow