Determination of the End-Diastolic Pressure Gradient Across the Mitral Valve at Mitral Commissurotomy

The attempted quantitation of mitral valvular obstruction from data obtained by right-heart catheterization1has been extended and refined by techniques designed to record pressures directly from the left atrium and left ventricle2-6and by the use of simultaneous right- and left-heart catheterization and central arterial pulse forms for the estimation of flow and pressures in the cardiovascular system.7-11These procedures have made possible a reasonably accurate assessment of mitral-valve obstruction prior to surgery and have allowed an estimation of the degree of relief obtained by surgical intervention.12,13The recent reports of "restenosis"14-20raise the question whether these diagnostic adjuncts may not be of value in evaluating the surgical procedure itself. This report concerns the application of the principles of left-heart catheterization to the operation of mitral commissurotomy, with a twofold purpose in mind: First, an accurate quantitation of the degree of mitral stenosis might be