To improve the standardisation and reproductibility of echocardiographic left ventricular mass (LVM) measurements we developed a specific software for automated measurements of LV diameter (EDD) and wall thickness (ST&PWT) from M mode recordings on SVHS videotapes using a dedicated computer system lô 3.3 (lôDP, Paris, France). Images are digitalised into 640 x 580 pixels with 256 grey levels. The algorithm computes the averages grey-level over an area of 10 pixels width based on the QRS on ECG and the profile obtained is analysed in order to estimate the position of wall interfaces with 2 choices: PENN or ASE conventions. We compared lô results performed twice at 1 week interval (lô 1&2) to conventional (Man) measurement (PENN convention) by a trained echocardiographist in 50 echos performed in hypertensives. Results are mean +/- SD, no significant difference was found between lô 3.3 and Man measurements with closed correlations. The reproductibility of the measurements is significatively improved by the automated procedure as well as the time to recover the results.