Natural History of Mitral Stenosis: A Review

T HE INTRODUCTION of cardiovascular surgery has profoundly influenced the natural history of many cardiac diseases. Availability of surgical means of benefiting serious heart disease-regardless of whether these means are curative of palliative-provides a powerful temptation to take advantage of such an opportunity. It is evident, however, that in many instances medical therapy may carry a much smaller risk than that of surgical intervention. It is therefore crucial to consider the natural history of a disease before a decision regarding surgery is made. The natural history of many diseases can no longer be observed, since it would be improper to withhold surgical help in certain advanced stages. Consequently, natural history often has to be extrapolated from older studies, which are incomplete by today's standards, and from observations of patients who for various reasons were not subjected to surgical therapy. In this review, we have attempted to analyze critically the natural history of mitral stenosis as it can be reconstructed today, and from these observations have attempted to formulate a rational therapeutic approach to this disease.