The parameterized diastolic filling (PDF) method is a method for analyzing the early diastolic filling phase of the left ventricle.

During early diastole, the left ventricle recoils from its compressed state in late systole. Its motion during this recoil can be accurately described as a case of damped harmonic motion, a mathematical model from classical mechanics.

Using this model, every filling phase can characterized in terms of the three constants load, stiffness and viscoelastic energy loss. As described by Dr Kóvacs, and implemented in Echo E-waves, the E-wave as recorded by PW Doppler during a conventional echocardiographic examination can be used as input to a mathematical function, resulting in the ouput of the three constants mentioned above. Thus, every E-wave can be used to obtain information on left ventricular diastolic load, stiffness and viscoelastic energy loss.