Figure 3.

Pictorial representation of central vessel waveform. P1 represents the pressure effected by the forward traveling wave. P2 minus P1 represents the amount of systolic pressure augmentation attributed to the reflected wave. P2 minus the diastolic blood pressure (DBP) is the central pulse pressure. The augmentation pressure (P2-P1) divided by the central pulse pressure is the Augmentation Index. The shaded area in the waveform estimates the effect of the reflected wave form on systolic workload.