Mitral valve area by pressure half time

Mitral valve area by pressure half time Measurement of mitral valve area by pressure half time is an often applied method using Doppler echocardiography. Mitral valve area by pressure half time Mitral valve area can be calculated from the pressure half time (PHT) of the initial downward slope of the mitral A wave, which fuses with the E wave in mitral stenosis. Lower the slope, lower the mitral valve area and higher the severity of mitral stenosis. Pressure half time is the time taken for the gradient to reduce to half of its peak value. PHT 220 ms corresponds to a mitral valve area of 1 square centimeter. Here the PHT is 163 ms, hence mitral valve area will be higher (machine calculated value displayed as 1.3 square centimeters). Mitral valve area by pressure half time: 220/PHT Mitral valve area calculated by PHT has its own limitations, especially in the immediate post balloon valvotomy situation where there is an abrupt hemodynamic change [1]. Error increases if there is significant mitral regurgitation [2]. How was the pressure half time formula derived? The value 220 in the pressure half time formula shown above is an empirical constant derived by Hatle J et al [3]. The relation between mitral valve area and fall in left atrial pressure when the mitral valve opens was noted as early as 1957 by Morrow AG et al during cardiac catheterization studies [4]. Libanoff AJ et al later used the pressure half time derived by cardiac catheterization to estimate mitral valve area [5]...
Source: Cardiophile MD - Category: Cardiology Authors: Tags: Echocardiography Source Type: blogs