Semi-continuous left atrial pressure measurements during mitral valvotomy.

or fracturing the commissures, but, as far as can be ascertained, few papers give detailed information about the merits of these pressure readings. In an earlier report from this hospital Pedersen and Tybjaerg Hansen (1953) published measurements from the left atrium in 15 cases. In 12 cases of valvotomy for mitral stenosis without significant regurgitation a decrease of pressure was recorded in every instance, averaging 11 mm. Hg (range 123 mm. Hg). In three cases of pure mitral incompetence, in which only exploration of the atrium