Advanced
Technical
IVT
aortic valve dimensionless index
Ratio of aortic valve area to left ventricular outflow tract area, used to assess aortic stenosis severity independently of flow conditions.
Full Definition
The aortic valve dimensionless index (DI) is calculated by dividing the aortic valve area by the left ventricular outflow tract area, providing a flow-independent assessment of aortic stenosis severity. This index is particularly useful in patients with low-flow states where traditional gradients may underestimate stenosis severity. A DI <0.25 generally indicates severe aortic stenosis and supports surgical intervention.
Usage
Usage note: Often abbreviated as DI; emphasize flow independence when describing clinical utility.
In Context
- "The dimensionless index of 0.18 confirmed severe aortic stenosis despite relatively low gradients." — Echocardiography report
- "In low-flow conditions, the dimensionless index provides more reliable stenosis assessment than pressure gradients." — Clinical guideline
Also known as
DI
dimensionless index
Don't confuse with
aortic valve area
aortic valve gradient