Usefulness of combined quantitative assessment of myocardial perfusion and velocities by myocardial contrast and doppler tissue echocardiography during coronary blood flow reduction

Abstract

Objectives: We sought to characterize regional myocardial perfusion and contraction in a closed-chest swine model during and after coronary blood flow reduction using myocardial contrast and Doppler tissue echocardiography. Methods and Results: Regional myocardial perfusion was assessed by myocardial contrast echocardiography using the corrected contrast peak intensity (baseline-subtracted contrast peak intensity), the peak intensity ratio (contrast peak intensity in ischemic/control wall), and a transmural video-intensity gradient. Regional peak systolic velocities and strain rate were measured using M-mode color Doppler tissue echocardiography. In 12 pigs, coronary blood flow reduction resulted in a significant decrease in peak intensity ratio and in peak systolic velocities in the subendocardium. At baseline and during ischemia, corrected contrast peak intensity and peak systolic velocities in the subendocardium, video-intensity gradient, and strain rate were closely related (r = 0.88 and 0.93, respectively). After reperfusion, in contrast to peak systolic strain rate that remained altered, the peak intensity ratio and video-intensity gradient recovered nearly baseline values. Conclusion: The combination of myocardial contrast and Doppler tissue echocardiography may distinguish between ischemic and postischemic myocardial wall dysfunction during severe coronary blood flow reduction. (J Am Soc Echocardiogr 2003; 16:1-8.)