Effects of isolated interventricular septal ischemia on global and segmental function of the canine right and left...

The effects of isolated septal artery ligation wee studied in 17 dogs. Contraction of the interventricular septum (IVS) and the free walls of both ventricles was measured by implanting ultrasonic crystals. Global ventricular function was assessed by Starling function curves. Following septal artery ligation, IVS shortening was immediately replaced by systolic lengthening. Thirty minutes after septal artery ligation, the right ventricular (RV) stroke work (SW) was significantly depressed at end-diastolic pressure (EDP) of 8 and 8.5 mm Hg from control values of 7.6 +/- 0.4 and 8.6 +/- 0.6 gmM to 6.7 +/- 0.4 and 7.4 +/- 0.5gmM respectively. However, LVSW after septal artery ligation was similar to control values for EDP from 5 to 19 mm Hg. These changes were associated with unchanged RV free wall movement of 21 +/- 3% in the inflow region and 23 +/- 5% in the outflow region. LV free wall systolic shortening following septal artery ligation increased by 16 +/- 3%. It is concluded that canine septal artery ligation causes global dysfunction of the RV but not of the LV.