[Regional work of the left ventricle before and after CABG]

To evaluate the effects of CABG on regional function of the left ventricular wall, regional work of the left ventricular anterior wall was calculated before and after CABG in 8 patients with multivessel coronary artery disease. In all patients, including CABG for LAD branch, complete revascularization was performed. Regional work of the left ventricular wall was calculated as RW (mJ/cm3) = - integral of sigma d epsilon, where sigma = wall stress and epsilon = regional strain (1n (1/H): H = wall thickness). A major and a minor axis, and anterior wall thickness during cardiac cycle were obtained from the left ventriculogram. Preoperatively, the RW varied widely (from -0.9 to 13.3 mJ/cm3). In 4 cases, the RW decreased and in the other cases, it increased. The RW converged in the tight range (from 2.5 to 6.7 mJ/cm3), postoperatively. These results suggest a uniformalization of the RW in the different regions of the left ventricle was established after the complete revascularization. We conclude that the RW obtained from the analyses of sigma-epsilon relationship is a useful index for evaluating the effects of CABG on the treated region of the left ventricle.