Myocardial Contrast Echocardiography for the Assessment of Coronary Blood Flow Reserve

ABSTRACT

BACKGROUND: The assessment of coronary blood flow reserve measured by intracoronary Dopper syudy is a useful method for evaluation of functional impairment of coronary artery disease irrespective of significant anatomic stenosis. To validate the usefullness of myocardial contrast echocardiography in clinical assessment of coronary blood flow reserve, several variables analysed by myocardial contrast echocardiography were compared with coronary flow reserve measured by Dopper catheter study. METHODS: During the coronary angiography, coronary flow reserve was measured by intracoronary Dopper-tipped guidewire with coronary blood flow velocity ratio in 16 patients without angiographically significant coronary artery disease. For the measurement of coronary flow reserve, we analyzed the time-video intensity curve of short axis image of the left ventricle follwing infusion of sonicated hexabrix before and after intracoronary administration of adenosine. RESULTS: 1) There was no significiant difference or correlation between peak intensity, peak intensity ratio, washout time, half time of washout, and washout time ratio analysed by contrast echocardiography and coronary blood flow reserve measured by intracoronary Doppler study(p>0.05). But inverse correlation was observed between half time ratio of contrast washout and coronary flow reserve(r=0.63,p<0.05). 2) There was no significiant difference between non myocardial infarction group and myocardial infartion group in coronary flow reserve and half time ratio of contrast washout. 3) No significant difference was observed before and after administrantion of sonicated hexabrix in hemodynamic variables. CONCLUSION: Among several variables of myocardial contrast echocardiography analysis half time ratio of washout was significantly correlated with coronary flow reserve. Thus assesssment of coronary flow reserve with myocardial contrast echocardiography is promising method in the evaluation of dymamic coronary perfusion and myocardial viability.