Peak aortic blood acceleration reflects the extent of left ventricular ischemic mass at risk

Peak aortic blood velocity (Vel), peak acceleration (Acc), stroke volume (SV), and left ventricular (LV) ejection fraction (EF) have been used as noninvasive indicators of global LV performance. The purpose of this study was to determine which of these indices of LV performance relates best to the extent of LV ischemic mass at risk. Studies were performed in 24 open-chest anesthetized dogs. Acute ischemia was produced by occlusion of various levels of the left anterior descending and circumflex coronary arteries. LV ischemic mass, measured as a percent of total LV mass, was delineated by injection of Evans blue dye into the nonischemic zone. Acc and Vel were measured with continuous-wave Doppler ultrasound. EF was measured angiographically. All parameters were measured during a control period and within 6 minutes of coronary occlusion. The percent change during ischemia of each parameter relative to control (% delta) was calculated. The correlation coefficient between the percent ischemic mass at risk and % delta Acc was 0.88. It was 0.84 for % delta EF, 0.77 for % delta Vel, and 0.17 for % delta SV. These results indicate that among the various global indices of LV performance that have been used noninvasively, Acc correlates most closely with the extent of LV ischemic mass at risk.