Systolic flutter of the mitral valve.

Systolic flutter of the mitral valve was observed in 11 cases during the past 3-1/2 years. All patients had mitral regurgitation due to mitral valve prolapse or flail leaflets, and nine of the 11 (82%) had prior or concurrent bacterial endocarditis. Systolic flutter is uncommon in the absence of endocarditis and was observed in only two of 15 patients (13%) with proven chordae tendinae or papillary muscle rupture without historical and pathological evidence of infection involving the mitral valve. Systolic flutter was also not seen in a large number of patients with mitral regurgitation due to other causes. It is postulated that the regurgitation jet of blood across the edge of a structurally abnormal but flexible mitral leaflet is important for the development of flutter.