Doppler ultrasound observation of pathological heart valves

A simple, noninvasive technique based on Hilbert transform (HT) time-signal displays is described. The authors discuss methods of showing forward- and reverse-flow Doppler echocardiograph signals as a time course of events relating to valve stenosis and regurgitation for providing additional cardiac insonation diagnostic information. The Doppler ultrasound demodulated signals are separated using the HT technique and then shown as segments of waveforms along with the corresponding electrocardiogram. This allows one to relate cardiac activity events, to assess valve leaflet thickness in severe mitral-valve stenosis cases, and to examine the opening and closing of valve leaflets for diagnosis