Final answer:
In severe valvular aortic stenosis, the onset of flow to peak aortic velocity Doppler tracing is increased.
Step-by-step explanation:
In severe valvular aortic stenosis, the onset of flow to peak aortic velocity on the Doppler tracing is increased. This means that the blood flow velocities in the aorta are higher compared to normal. This is due to the increased pressure gradient across the stenotic valve, causing the blood to accelerate and reach peak velocity earlier in systole.