[Congenital mitral stenosis. Report on 33 patients].

Thirty-three patients with congenital mitral stenosis are presented. Congenital mitral stenosis occurs as an isolated malformation and in combination with additional cardiac lesions. A new classification into 5 groups is suggested. It is possible to classify congenital mitral stenosis with and without additional lesions according to these 5 groups. This is of particular clinical advantage. Isolated congenital mitral stenosis is a rare malformation. In combination with additional obstructive left-sided cardiac malformations mitral stenosis occurs more frequently. In infancy and early childhood the so-called parachute valve is a stenotic lesion. According to our experience the parachute valve tends to the development of additional mitral incompetence in older children. This observation is of clinical and diagnostic importance. In patients with additional valvular aortic stenosis the mortality is very high. The operative treatment of congenital mitral stenosis with a parachute valve in combination with other obstructive lesions of the left ventricular outflow tract and the aorta without removal of the parachute valve seems to be unable to improve the hemodynamic situation and the prognosis of these patients. There is not enough experience with artificial valves in congenital mitral stenosis in early childhood.