Cardiac catheterization, which is the insertion of a catheter into the heart, is the definitive method for diagnosing Aortic stenosis, typically first discovered during ultrasound.
Cardiac catheterization (heart cath) is the insertion of a catheter into a chamber or vessel of the heart. Cardiac chamber catheterization provides a definitive diagnosis, indicating severe stenosis in valve area of <1.0 cm (normally about 3 cm). Ultrasound of the heart 
