The Physiologic Evaluation of Patients Before and After Mitral Commissurotomy

1) The resting cardiac output of patients with mitral stenosis is normal, and does not decrease until the onset of heart failure. 2) Pressure levels are more critical than flow levels in estimating the function of the right heart. 3) The most adequate picture of the right ventricular function is obtained from an analysis of pulmonary resistance and of the work of the right ventricle. 4) Patients who are most likely to benefit from mitral commissurotomy are those with high pulmonary artery pressures. 5) The degree of fall of the pulmonary artery pressure following commissurotomy is roughly parallel to the degree of clinical improvement in the few cases studied. 6) Patients with very low pulmonary artery pressures are not benefited by mitral commissurotomy and such low initial pressures may be present in patients with low grade rheumatic myocarditis. 7) Comparison of pre- and postoperative catheterization findings is the only critical method of evaluating results of mitral commissurotomy and should be further pursued. We wish to acknowledge the technical assistance of Mrs. Helen Obernolte, Dr. Andrew Farr, Miss Mary Mayo and Mr. Lucius Collier.