Fig. 5.
Example of an aortic pressure waveform of a nominal pulse height from diastolic pressure (DP) to systolic pressure (SP). The anacrotic shoulder is associated with the commencement of augmentation of the forward-going pressure wave by the reflected pressure wave. The pressure at which this occurs is the inflection pressure (Pi). The incisura, not to be confused with the dicrotic notch seen in more peripheral waves, is associated with the closing of the aortic valve and the end of systole (Pes). The dotted line shows an estimated flow wave of arbitrary units using these points as a guide for the waveform shape. The subendocardial viability ratio can be calculated as the ratio of systolic area to diastolic area.