THE DIAGNOSIS OF MITRAL INCOMPETENCE FROM LEFT ATRIAL PRESSURE CURVES

Abstract

Left atrial and ventricular pressure tracings were taken at operation on 77 patients with mitral valve disease. Neither the height of the v wave measured from the atrial pressure immediately preceding the a or c wave nor the maximum height of the v wave above the maximum height of the c wave (v-c difference) correlated well with the degree of mitral incompetence as estimated by palpation of the mitral orifice. Likewise, the Ry/v ratio (Owen and Wood, 1955) did not correlate. However, the "corrected x descent", calculated by subtracting (1) the atrial pressure just prior to the a or c wave and (2) the height of the c wave from the pressure at the nadir of x descent (or if there is no x descent, the atrial pressure is measured at the end of the first 3d of ventricular diastole), was felt to be of value. When the "corrected x descent" is > 5 mm Hg, there is mitral incompetence; when it is under 5 mm Hg, there is no severe incompetence although moderate incompetence may exist.