Figure 1From: Arterial stiffness in adult patients after Fontan procedure The pulse waveform in the ascending aorta. P1 - the first systolic peak caused by the force of myocardial contraction, P2 - the second peak caused by pulse wave reflected returning from the periphery to the heart, AP (AP = P1 - P2) - augmented pressure, PP - (pulse pressure).Back to article page