Pulmonary capillary wedge pressure in mitral stenosis accurately reflects mean left atrial pressure but overestimates transmitral gradient

Mean pulmonary capillary wedge pressure correlates well with mean left atrial pressure in MS. However, transmitral gradient assessed using pulmonary capillary wedge pressure varies significantly from that assessed using left atrial pressure, and is too inaccurate for routine clinical use. This disparity is due to the phasic delay inherent in capillary wedge traces and the dampened post-v-wave descent. We suggest that, rather than undergo cardiac catheterization with routine overestimation of transmitral gradient, patients with MS should be referred on the basis of symptoms and echocardiography alone, with balloon mitral valvuloplasty performed as appropriate at one-stop cardiac catheterization.