The diastolic pressure gradient between the left atrium and the left ventricle in cases of mitral stenosis

Abstract

1. 1. The end-diastolic pressure gradient between the left atrium and the left ventricle has been determined at rest in 63 patients with mitral valvular lesion. The diagnosis was verified at surgery in all cases. 2. 2. In all patients with a mitral stenosis, there was a positive end-diastolic pressure gradient between the left atrium and the left ventricle, varying between 36 and 1 mm. Hg. In 56 of these patients who had mitral lesions with a dominating mitral stenosis the pressure gradient averaged 10.5 mm. Hg. In 10 patients it was less than 5 mm. Hg. A corresponding pressure gradient could not be observed in 7 patients who had an aortic lesion without a mitral lesion. 3. 3. In 14 patients in whom the minute volume was determined during the measurement of the pressure gradient, there was a slight but probably significant correlation between these two factors. 4. 4. No correlation could be observed between the degree of the pressure gradient and the size of the orifice as measured by the surgeon's observations. Furthermore, in this material no correlation could be found between the pressure gradient and the heart volume or the patient's working capacity. 5. 5. A diastolic pressure gradient over the mitral orifice of at least 5 mm. Hg will indicate the presence of a stenotic component in the mitral valves. However, such a pressure gradient does not help to distinguish cases of pure mitral stenosis from those with a concomitant mitral regurgitation, nor to evaluate the degree of such mitral regurgitation.