End-systolic pressure-volume relations.

tive prosthetic orifice size may have to be performed at least a few weeks after valve insertion. Second, in some patients, the problem is compounded by the small size of the annulus compared with the size of the patient. My article was not written just to highlight the difficulties of a small aortic annulus. Dr. Kinsley's ability to insert a prosthetic valve size commensurate with the patient's body size is to be applauded. However, Dr. Kinsley's letter and previous paper' leave many questions unanswered. The technique of anticipating stroke volume and tailoring the prosthetic valve to that stroke volume is not described. The belief that favorable hemodynamic characteristics are actually enhanced is not based on data that have been presented. Although gradients obtained at surgery are cited, calculated prosthetic valve areas and valve area indices of patients studied some weeks or months after surgery have not been presented. It would also be of interest to know how many patients had aortic valve replacement without use of this technique during the same period of time when the 52 patients were operated on with use of this technique. There have been two deaths with the use of this technique, and some patients already have aortic incompetence; moreover, the device is inserted in an abnormal position. Before one is convinced that the technique is safe and effective, one should know: 1) the long-term mortality and morbidity of patients so treated and the data analyzed with the use of actuarial techniques;5 and 2) the results of detailed hemodynamic evaluation which provide information about prosthetic valve areas, frequency and severity of valvular regurgitation and about ventricular performance. SHAHBUDIN S. RAHIMTOOLA, M.D. Visiting Professor University of California, San Francisco San Francisco, California 94143