Author + information
- Received September 25, 2000
- Revision received February 20, 2002
- Accepted February 25, 2002
- Published online May 15, 2002.
- Yutaka Otsuji, MD, FACC*,* (, )
- Toshiro Kumanohoso, MD*,
- Shiro Yoshifuku, MD*,
- Keiko Matsukida, MD*,
- Chihaya Koriyama, MD†,
- Akira Kisanuki, MD*,
- Shinichi Minagoe, MD*,
- Robert A. Levine, MD, FACC‡ and
- Chuwa Tei, MD, FACC*
- ↵*Reprint requests and correspondence:
Dr. Yukata Otsuji, First Department of Internal Medicine, Kagoshima University School of Medicine, 8-35-1 Sakuragaoka, Kagoshima City, 890-8520, Japan.
Objectives We sought to test whether isolated mitral annular (MA) dilation can cause important functional mitral regurgitation (MR).
Background Mitral annular dilation has been considered a primary cause of functional MR. Patients with functional MR, however, usually have both MA dilation and left ventricular (LV) dilation and dysfunction. Lone atrial fibrillation (AF) can potentially cause isolated MA dilation, offering a unique opportunity to relate MA dilation to leaflet function.
Methods Mid-systolic MA area, MR fraction, LV volumes and papillary muscle (PM) leaflet tethering length were compared by echocardiography among 18 control subjects, 25 patients with lone AF and 24 patients with idiopathic or ischemic cardiomyopathy (ICM).
Results Patients with lone AF had a normal LV size and function, but MA dilation (isolated MA dilation) significant and comparable to that of patients with ICM (MA area: 8.0 ± 1.2 vs. 11.6 ± 2.3 vs. 12.5 ± 2.9 cm2[control vs. lone AF vs. ICM]; p < 0.001 for both lone AF and ICM). However, patients with lone AF had only modest MR, compared with that of patients with ICM (MR fraction: −3 ± 8% vs. 3 ± 9% vs. 36 ± 25%; p < 0.001 for patients with ICM). Multivariate analysis identified PM tethering length, not MA dilation, as an independent primary contributor to MR.
Conclusions Isolated annular dilation does not usually cause moderate or severe MR. Important functional MR also depends on LV dilation and dysfunction, leading to an altered force balance on the leaflets, which impairs coaptation.
☆ This study was supported by a grant of Fukuda Foundation of Medical Technology and by a Grant-in-Aid for Scientific Research (no. 13670730) from the Japan Society for the Promotion of Science, Tokyo, Japan. Dr. Minagoe was also supported by a Grant-in-Aid for Scientific Research (no. 12670682) from the Japan Society for the Promotion of Science, Tokyo, Japan.
- Received September 25, 2000.
- Revision received February 20, 2002.
- Accepted February 25, 2002.
- American College of Cardiology Foundation