Chisato Izumi, MD, Kanji Iga, MD, Hirokazu Kondo, MD, Toshihiro Tamura, MD, Moriaki Inoko, MD, Shoji Kitaguchi, MD, Toshiro Hirozane, MD, Yoshihiro Himura, MD, Hiromitsu Gen, MD, Yuichi Ueda, MD*, Takashi Konishi, MD

Background. Mitral regurgitation (MR) associated with secondum atrial septal defect (ASD) sometimes develops several years after ASD closure.

Methods. To clarify the clinical characteristics of progressive MR after ASD closure, we evaluated valve anatomy, the thickness of the anterior mitral leaflet, and the diameter of the mitral annulus in 50 patients with secondum ASD by transthoracic echocardiographms.

Results. During the follow-up period, MR progressed in five patients (groupA), but not in the other 45 patients (groupB). Atrial fibrillation was seen in all groupA patients, but only in 24% of groupB patients. The anterior mitral leaflet was thicker in groupA than groupB in the preoperative echocardiograms. In the postoperative echocardiograms, the mitral annulus diameters were longer in groupA than groupB and they disproportionally increased between the long axis and four chamber views in some patients of groupA.

Conclusions. Progressive MR was seen in 10% of patients with ASD closure, especially aged patients with thickened mitral leaflets and atrial fibrillation before the operation. The dilatation or deformation of the mitral annulus were related to progressive MR indicating serial echocardiographic examinations are necessary in following patients after ASD closure.