2004 Volume 2 Issue 1 Pages 1-6
Background. Intravenous myocardial contrast echocardiography (MCE) has emerged as a novel method for assessment of myocardial blood volume (MBV), which changes in proportion to coronary stenosis severity at rest. The purpose of this study was to clarify the relation between phasic changes in MBV and the severity of coronary artery stenosis in humans.
Methods. We studied 58 patients with suspected coronary artery disease who underwent MCE with harmonic power Doppler imaging and continuous infusion of Levovist. Both end-systolic and end-diastolic images were obtained separately at every cardiac cycle. Regions of interest were placed at the mid-septum, and phasic changes in myocardial signal intensity (SI) were calculated as (SI at end-diastole)-(SI at end-systole).
Results. Twenty-four patients had significant coronary stenosis in the left anterior descending coronary artery (LAD), and 34 did not. The phasic changes in patients with LAD stenosis were significantly lower than that in patients without LAD stenosis (−0.5±1.2dB vs. 1.3±1.4dB, p<0.001). For the presence of >70% stenosis in LAD, the phasic changes <0.4 was the optimal cut-off value which provided sensitivity of 75%, specificity of 71% and accuracy of 73%.
Conclusions. Phasic changes in MBV assessed by MCE have the potential for detection of coronary artery stenosis in the clinical setting at rest.