The case is reported of mitral valve repair with cusp-level chordal shortening for non-rheumatic mitral anterior leaflet prolapse. The simple and easily reproducible cusp-level shortening procedure consists of plication of the redundant chorda underneath the leaflet. Provided the chorda is thick enough, this procedure is more likely to be applied to regional mitral anterior prolapse due to elongation of the chorda, even in patients with non-rheumatic heart disease. The present patient underwent perioperative adaptive servo-ventilation (ASV) therapy. ASV might help to prevent atrial fibrillation recurrence after the Maze procedure by reducing sympathetic overactivity, contributing to the durability and outcome of mitral valve repair with cusp-level chordal shortening.