3-DIMENSIONAL ECHOCARDIOGRAPHIC ESTIMATION OF INFARCT MASS BASED ON QUANTIFICATION OF DYSFUNCTIONAL LEFT-VENTRICULAR MASS

Background Two-dimensional echocardiography is useful for estimating t he extent of infarct-related wall motion abnormalities. Such estimatio n, however, is based on a few selected views and extrapolated for the whole left ventricle (LV). This approach does not provide us with the actual amount of dysfunctional myocardium. Volume-rendered three-dimen sional echocardiography (3DE) might overcome these limitations. In thi s study we explored (I) how well volume-rendered 3DE delineates region al dysfunction of the infarcted LV and (2) how well dysfunctional myoc ardial mass quantified by 3DE reflects the actual anatomic infarct mas s. Methods and Results 3DE was performed before and 3 hours after coro nary occlusion in 16 dogs. With the LV viewed in equidistant short-axi s slices, the region of dysfunction was demarcated, and the dysfunctio nal myocardial mass was derived from this. With triphenyltetrazolium c hloride staining, anatomic infarct regions were delineated, dissected, and weighed. The anatomic infarct mass was 16.3+/-7.7 g (mean+/-SD) ( range, 6.4 to 31.4 g); the dysfunctional mass estimated by 3DE was 17. 4+/-9.1 g (range, 5.2 to 39.0 g). The mean difference was 1.0 g. The c orrelation between dysfunctional mass Oil and infarct mass (x) was y=1 .1x-0.6, r=.93 (P<.0001). The percentage of LV involved in infarction was 18.2+/-5.8% (range, 9.1% to 26.1%); the percentage of LV involved in regional dysfunction was 18.3+/-6.9% (range, 7.9% to 31.2%). The me an difference was 0.1%. The correlation between percentage of LV invol ved in Infarction (x) and percentage of LV involved in dysfunction (y) was y=1.0x-1.1, r=.92 (P<.0001). Conclusions Volume-rendered 3DE cris ply displays regional dysfunction of infarcted LV. 3DE-measured dysfun ctional mass accurately reflects the anatomic infarct mass.