Aetiology of surgically treated mitral regurgitation.

The aetiologies of mitral regurgitation were reviewed in 336 patients operated on between 1970 and 1990. The relative frequency of rheumatic fever has decreased and the most common cause is now primary mitral valve prolapse (PMVP) which accounts for 60% of all patients. The increasing age of the surgical population seems to be one of the main factors of this change. Conservative surgical repair according to Carpentier's technique is now performed in 60% of all patients with mitral regurgitation and 80% of cases of PMVP. The aetiology of PMVP is still under discussion. Surgical description seems to indicate the existence of two different morphological aspects with significantly different rates and localizations of chordae ruptures, but our study failed to demonstrate any other anatomical, clinical or histological differences between the two groups.