Non invasive estimation of pulmonary artery pressure (PAP) is of paramount importance in var!ous form of cardiac, respiratory and intensive care medicinc practice. Using pressure gradient between different chambers enablcs a reliablc estimation of PAP and are being largely practiced. In absence of these pressurc gradient, various time interval or the ratios of pulmonary blood now velocit), curve (PBFVC) in pulsed wave doppler echocardiography (PWDE) can predict the PAP. But there is lack of general agreement as which parameter should be used. We hypothesized that using separate time interval or their ratios of PBFV C for different group of patient may improve the PWDE prediction of PAP.