dicrotic notch
Pronunciation: die-KROT-ik
Characteristic deflection in arterial pressure waveform corresponding to aortic valve closure during cardiac cycle.
Full Definition
The dicrotic notch is a distinctive downward deflection seen in arterial pressure waveforms that occurs during early diastole, marking the closure of the aortic valve and the transition from systole to diastole. This waveform feature results from the brief reversal of blood flow that causes aortic valve closure, creating a momentary pressure drop followed by the dicrotic wave. In cardiothoracic anesthesia, analysis of the dicrotic notch provides valuable information about cardiac function, vascular compliance, and hemodynamic status. The timing and amplitude of the notch can be affected by factors such as heart rate, contractility, and afterload.
Usage
Usage note: From Greek 'dikrotos' meaning double-beating; maintain consistent spelling.
In Context
- "The arterial waveform displayed a prominent dicrotic notch, indicating good aortic valve competence." — Hemodynamic monitoring note
- "Loss of the dicrotic notch in the pressure tracing suggested significant aortic regurgitation." — Intraoperative observation