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Figure 2 Signal-averaged data of left ventricular pressure–volume loops at baseline (before the beginning of the inflation of vascular occlusion balloon) during right ventricular apical (A), left ventricular free wall (B), and biventricular pacing (C) in the patient of Figure 1. Left ventricular–based pacing consistently shifted the end-systolic pressure–volume point upwards and to the left, and the end-diastolic pressure–volume point downwards and to the right. The area of the entire loop increased, indicating that left ventricular free wall and biventricular pacing produce a more effective contraction than does conventional right ventricular apical pacing.