Estimation of PCWP from E/E ’ on Tissue Doppler Imaging

Estimation of PCWP from E/E’ on Tissue Doppler Imaging Conventionally, pulmonary capillary wedge pressure (PCWP) is measured using a catheter in the pulmonary artery. Pulmonary artery diastolic pressure measured by a Swan Ganz balloon floatation catheter at bedside is often taken as the surrogate of PCWP. Ideal method of bedside measurement is balloon occlusion of a pulmonary artery branch to get the distal pressure. But it cannot be done on a continuous basis as it will compromise flow to the territory and vascular complications can ensue. True PCWP, as the name implies, is obtained after wedging an end hole catheter with no side holes (Cournand catheter), during right heart catheterization. Nagueh formula can be used for calculation of PCWP from the Doppler derived mitral E/E’ ratio [1]. PCWP is usually equal to the left atrial pressure and hence the left ventricular filling pressure. E’ (Ea) has been considered as a preload independent index of left ventricular relaxation. Nagueh formula uses mitral E velocity during early diastolic flow corrected for the influence of left ventricular relaxation (E/E’ ratio) to estimate the mean PCWP [1]. Nagueh formula: PCWP = 1.24 [E/E’] + 1.9 Ea was taken from the lateral mitral annulus in the pioneering study of Nagueh SF et al. 60 patients had invasive measurement of PCWP and simultaneous Doppler echocardiography [1]. Comparison of pulmonary arterial diastolic pressure by an implantable device known...
Source: Cardiophile MD - Category: Cardiology Authors: Tags: Echocardiography Estimation of PCWP from E/E' Nagueh formula Source Type: blogs