Value of acceleration flow in the left anterior descending coronary artery for the detection of coronary artery stenosis by transthoracic coronary color Doppler echocardiography.

Whether the localized flow acceleration occurs in the resting stenotic left anterior descending coronary artery was explored and its value for detection of coronary stenosis estimated. Blood flow in the left anterior descending coronary arteries in 45 patients was detected by transthoracic color Doppler echocardiograph and multipoint pulse Doppler spectrums were recorded in the same segment. The ratio of the maximal peak diastolic velocity to the minimal peak diastolic velocity was calculated. The ratio > or = 1.5 was the cutoff value for the presence of localized acceleration flow. There were 23 patients with localized acceleration flow examined by echocardiography. Twenty of them were found to have luminal diameter stenosis (60% - 98%) in the left anterior descending coronary arteries by coronary angiography and 3 patients were normal. There were 22 patients without localized acceleration flow examined by echocardiography. Eighteen of them had no or < 60% stenosis. Four patients had serious stenosis (> or = 95%) or occluded segments in the left anterior descending coronary arteries on coronary angiography. The ratio of the maximal peak diastolic velocity to the minimal peak diastolic velocity was significantly higher in patients with left anterior descending coronary artery stenosis than that in those without stenosis (1.9 +/- 0.3 vs 1.3 +/- 0.2, P < 0.01) and it correlated significantly with left anterior descending coronary artery stenosis (r = 0.77, P < 0.01). The specificity by using the ratio > or = 1.5 for stenosis detection was 85.7% (18/ 21), and the sensitivity was 83.3% (20/24). This study demonstrated that local blood flow velocity was increased in the resting stenotic left anterior descending coronary artery. Transthoracic color Doppler echocardiography is a reliable noninvasive method to detect localized acceleration flow in the left anterior descending coronary artery stenosis and it is useful in the noninvasive diagnosis of stenosis in the left anterior descending coronary artery.