The incisura portion of the aortic pressure occurs immediately after which action?

The incisura or dicrotic notch in the aortic pressure waveform occurs immediately after the aortic valve closes. This notch represents a brief moment where there is a slight rebound in pressure due to the closure of the valve, which prevents backflow into the left ventricle. As the aortic valve closes, the pressure in the aorta briefly decreases, but the continued momentum of blood flow creates a characteristic dip in the pressure tracing known as the incisura.

Understanding this phenomenon is key in interpreting the aortic pressure curve, as it provides insight into the hemodynamics of the heart and the functioning of the aortic valve during the cardiac cycle. The other choices do not correlate with the timing of the incisura and do not produce this specific pressure change in the aorta following their episodes in the cardiac cycle.