The Doppler method of obtaining left ventricular Max(dP/dt) proposed recently was based on the measurement of mitral regurgitation velocity. Since Max(dP/dt) is an isovolumic phase index, its use in cases of mitral regurgitation may be open to argument. However, we had proposed a noninvasive method of estimating left ventricular Max(dP/dt) based on different principles. In our method, Max(dP/dt) had been given by Max(dP/dt) = (rho)cMax (du/dt), where rho is the blood density, c is the pulse wave velocity, and u is the flow velocity in the aorta. We had derived the above equation theoretically, and confirmed its validity by animal experiments. In our previous study, we also applied our method in the clinical setting. The aortic flow velocity was measured by Doppler echocardiography, and the pulse wave velocity by mechanocardiography or Doppler echocardiography. (Rho)cMax(du/dt) obtained noninvasively was compared with Max(dP/dt) measured with a catheter-tip micromanometer. We found an excellent correlation between (rho)cMax(du/dt) and Max(dp/dt), and concluded that (rho)Max(du/dt) is useful in assessing noninvasively the contractile state of the left ventricle. Here, we summarize our method, review previous results, and report new results of the clinical application of our method.