The pulse wave is broad in the ascending aorta. The ascending portion of the pulse wave is the anachrotic limb and the descending portion is the catachrotic limb. The dichrotic notch on the descending portion results from closure of the aortic valve.
The diastolic pressure is found immediately before the beginning of the ascending limb, while the systolic pressure is reached at the peak of the pulse wave. The difference between the two is the pulse pressure.