Aortic Regurgitation

A leaky one-way door in a water system

Imagine a one-way door (the aortic valve) that lets water flow out of a tank (the left ventricle) into a big pipe (the aorta) when you push the door open, then snaps shut to stop backflow when you release it. In aortic regurgitation, the door warps (leaflet damage) or the frame it sits in stretches (root dilation), so it never closes all the way—water constantly seeps backward into the tank during the resting phase. A normal tank can handle this for a while by stretching its walls (eccentric hypertrophy) to pump out both the fresh water coming in and the leaked water, so the system keeps working. But the pump works twice as hard, and pressure in the big pipe swings wildly—shooting high when you push (wide systolic pressure) and dropping fast as water leaks back (low diastolic pressure). Eventually the tank's walls give out, it cannot stretch anymore, and the system floods backward into the lungs (pulmonary swelling (edema)). If the leak suddenly gets huge, the tank gets crushed before it can stretch, and the system shuts down immediately (acute shock).