Schematic presentation of normal Doppler flow across the aortic (A) and mitral (B) valves. Abnormal continuous wave Doppler profiles: C. Aortic stenosis (AS) (peak transaortic gradient = 4 × V_max² = 4 × [3.8]² = 58 mmHg) and regurgitation (AR). D. Mitral stenosis (MS) and regurgitation (MR).