When does the incisura portion of the aortic pressure wave occur?

The incisura portion of the aortic pressure wave occurs immediately after the aortic valve closes. This is an important phase in the cardiac cycle that reflects a specific moment when the left ventricle has finished ejecting blood into the aorta, and the aortic valve has clamped shut. At this point, there is a brief but noticeable dip in the aortic pressure before it stabilizes, which is visually represented as the incisura or dicrotic notch on a pressure waveform.

This dip occurs due to the sudden decrease in blood flow from the left ventricle, which contrasts with the continued pressure in the aorta as the elastic walls of the artery maintain some degree of force. Understanding this timing is crucial for interpreting aortic pressure waveforms and cardiac function, making it a fundamental concept in adult echocardiography and cardiovascular physiology.