Thirty-eight patients were operated on for mitral stenosis between March 1979 and September 1981. Thirty-six of them were examined as to their age, symptom duration, chest roentgenograms, electrocardiograms and echocardiograms to obtain various indices of left ventricular function. The usefulness of these indices as preoperative risk factors for predicting postoperative low cardiac output syndrome (LOS) was investigated. Cases which had values of ejection fraction, cardiac index, percent fiber shortening or mean velocity of circumferential fiber shortening less than 0.45, 2.0 l/min/m2, 25% and 0.80 circ/sec, respectively, in the preoperative echocardiographic examination were associated with a greater chance of postoperative LOS. Each of these factors was independently useful as a risk factor in cardiac surgery for mitral stenosis. Moreover, it was revealed that the combination of a preoperative percent fractional shortening (%FS) of less than 30% and a cardiac index smaller than 2.0 l/min/m2 indicated a strong predisposition toward postoperative LOS.</p
