What is the most common cause of mitral stenosis?

The most common cause of mitral stenosis is rheumatic heart disease, which typically results from complications following rheumatic fever—a condition caused by untreated streptococcal throat infections. Over time, repeated episodes of rheumatic fever can lead to inflammation and scarring of the heart valves, specifically affecting the mitral valve. This scarring eventually narrows the valve opening, causing mitral stenosis.

Understanding the historical context of rheumatic fever is essential; it was far more common before the widespread use of antibiotics for streptococcal infections. As a result, many patients who experienced rheumatic fever in childhood can develop mitral stenosis later in life as a long-term complication. While calcific degeneration and degenerative valve disease are important in the broader context of heart valve issues, they are more commonly associated with aortic stenosis rather than mitral stenosis, especially in elderly populations. Congenital anomalies can result in stenotic conditions, but they are less prevalent compared to rheumatic heart disease when discussing the overall incidence of mitral stenosis in the general population. Hence, rheumatic heart disease stands out as the primary culprit in this condition.