What is the dicrotic notch and what does it signify to the nurse?

Cardiac term: It is s secondary part of a pulse tracing corresponding to the transient increase in aortic pressure upon closure of the aortic valve. To a physician this is not complicated but to the layman it may not be very clear. The best thing to do is to go over the tracing with your family physician or cardiologist.

It is the: sudden drop in blood pressure after systolic(ventricular) contraction. It is due to the backwards flow of blood in the arteries when the aortic valve is still in closing up phase. This is a normal part of vascular physiology.

Closure of valves: The tracing of the pressure curves of the pulmonary artery and aorta demonstrate a characteristic rise with a peak followed by a rapid fall until the pulmonic valve and the aortic valve close. At that point, there is a transient rise of pressure in both arteries, creating a notch in the waveform, termed the dicrotic notch, following which the pressure continues to fall until the cycle repeats.