Normal or expected range for an aorta root is 2.0 - 3.7 cm or 20mm - 37mm. A narrow aorta opening (orifice) is medically referred to stenosis. Usually stenosis is the result of calcification, and if considered serious the valve can be repaired or replaced. The 1.9 cm may not cause any problems, but if there develops a problem the left ventricle can enlarge due to the gradient pressure.