Figure 2. Systolic arterial pressure (SBP) and end-systolic meridional wall stress (SWS), parameters that correspond to left ventricular afterload, are decreased in intraaortic balloon counterpulsation-augmented (A) cardiac beats compared to subsequent nonaugmented (N⁰, N¹, N², and N³) cardiac beats. All values (n = 27) are the mean +/-SE. Comparisons were performed using analysis of variance for repeated measures adjusted for multiple comparisons.