Two-dimensional echocardiography correlated well with reference methods for estimating LV dyssynergy and infarct size (r=0.89), but correlated poorly in the presence of coronary reflow (r=0.39).
Does two-dimensional echocardiography accurately estimate the extent of myocardial dyssynergy and infarct size compared to force-gauge mapping and NBT staining in a canine model of ischemia and infarction?
Two-dimensional echocardiography provides an adequate estimate of LV dyssynergy and infarct size during acute ischemia or permanent occlusion, but is inaccurate following reperfusion due to the discrepancy between myocardial viability and functional recovery.
Effect estimate: r = 0.89
The extent of left ventricular (LV) dyssynergy was assessed noninvasively in 19 dogs with two-dimensional echocardiographic short-axis sections during myocardial ischemia and infarction. After coronary occlusion, two-dimensional echocardiography uniformly indicated an increase in LV end-diastolic volume and a decrease in LV ejection fraction. Two-dimensional echocardiographic measurements of dyssynergy were evaluated and compared in three subgroups against (1) the extent of LV dyssynergy determined by force-gauge mapping during 10 coronary occlusions of 30-60 minutes' duration in eight open-chest dogs, (2) infarct size delineated by nitroblue tetrazolium (NBT) staining of left ventricular slabs after 48 hours of left anterior descending coronary artery (LAD) occlusion in five closed-chest dogs, and (3) NBT infarct size after 3-hour LAD occlusion followed by 45 hours of reperfusion in six closed-chest dogs. Linear regression analysis of results from these three comparisons gave good correlations (r = 0.89) for groups 1 and 2; in group 2, the extent of dyssynergy by two-dimensional echocardiography was consistently greater than infarct size by NBT. In group 3, the correlation was poor (r = 0.39). These results suggest that an adequate estimate for the extent of LV dyssynergy or infarct size may be obtained with two-dimensional echocardiography during myocardial ischemia or infarction, but not in the presence of coronary reflow, which causes an acute discrepancy between myocardial viability and function.
Wyatt et al. (Sun,) conducted a other in Myocardial ischemia and infarction (n=19). Two-dimensional echocardiography vs. Force-gauge mapping and nitroblue tetrazolium (NBT) staining was evaluated on Correlation between extent of LV dyssynergy by 2D echocardiography and reference methods (r = 0.89). Two-dimensional echocardiography correlated well with reference methods for estimating LV dyssynergy and infarct size (r=0.89), but correlated poorly in the presence of coronary reflow (r=0.39).