Figure 7. The mean change+/-SE in echocardiographic parameters of left ventricular systolic function during the transition from intraaortic balloon counterpulsation (IABP) off to an IABP-to-R wave trigger ratio of 1:1 were measured both before and after myocardial revascularization in 7 patients who underwent CABG for unstable angina. The improvement in left ventricular systolic function as a consequence of IABP was not different after revascularization.