This Article Full Text Full Text (PDF) Alert me when this article is cited Alert me if a correction is posted Citation Map Services Email this article to a friend Similar articles in this journal Similar articles in PubMed Alert me to new issues of the journal Download to citation manager Request Permissions Citing Articles Citing Articles via HighWire Citing Articles via Google Scholar Google Scholar Articles by Schwammenthal, E. Articles by Levine, R. A. Search for Related Content PubMed PubMed Citation Articles by Schwammenthal, E. Articles by Levine, R. A. Pubmed/NCBI databases Medline Plus Health Information Cardiomyopathy

(Circulation. 1998;98:856-865.)
© 1998 American Heart Association, Inc.

Clinical Investigation and Reports

Mechanism of Mitral Regurgitation in Hypertrophic Cardiomyopathy

Mismatch of Posterior to Anterior Leaflet Length and Mobility

Ehud Schwammenthal, MD, PhD; Satoshi Nakatani, MD; Shengqiu He, MD; Joanne Hopmeyer, BS, ChE; Alex Sagie, MD; Arthur E. Weyman, MD; Harry M. Lever, MD; Ajit P. Yoganathan, PhD; James D. Thomas, MD; ; Robert A. Levine, MD

From the Noninvasive Cardiac Laboratory, Massachusetts General Hospital, Department of Medicine, Harvard Medical School, Boston, Mass (E.S., A.S., A.E.W., R.A.L.); the Cardiovascular Imaging Center of the Department of Cardiology, Cleveland Clinic Foundation, Cleveland, Ohio (S.N., H.M.L., J.D.T.); and the Cardiovascular Fluid Mechanics Laboratory, School of Chemical Engineering, Georgia Institute of Technology, Atlanta, Ga (S.H., J.H., A.P.Y.).

Background—In hypertrophic cardiomyopathy, a spectrum of mitral leaflet abnormalities has been related to the mechanism of mitral systolic anterior motion (SAM), which causes both subaortic obstruction and mitral regurgitation. In the individual patient, SAM and regurgitation vary in parallel; clinically, however, great interindividual differences in mitral regurgitation can occur for comparable degrees of SAM. We hypothesized that these differences relate to variations in posterior leaflet length and mobility, restricting its ability to follow the anterior leaflet (participate in SAM) and coapt effectively.

Methods and Results—Different mitral geometries produced surgically in porcine valves were studied in vitro. Comparable degrees of SAM resulted in more severe mitral regurgitation for geometries characterized by limited posterior leaflet excursion. Mitral geometry was also analyzed in 23 patients with hypertrophic cardiomyopathy by intraoperative transesophageal echocardiography. All had typical anterior leaflet SAM with significant outflow tract gradients but considerably more variable mitral regurgitation; therefore, regurgitation did not correlate with obstruction. In contrast, mitral regurgitation correlated inversely with the length over which the leaflets coapted (r=-0.89), the most severe regurgitation occurring with a visible gap. Regurgitation increased with increasing mismatch of anterior to posterior leaflet length (r=0.77) and decreasing posterior leaflet mobility (r=-0.79).

Conclusions—SAM produces greater mitral regurgitation if the posterior leaflet is limited in its ability to move anteriorly, participate in SAM, and coapt effectively. This can explain interindividual differences in regurgitation for comparable degrees of SAM. Thus, the spectrum of leaflet length and mobility that affects subaortic obstruction also influences mitral regurgitation in patients with SAM.

Key Words: mitral valve • echocardiography • regurgitation • cardiomyopathy

This article has been cited by other articles:

				A. J. Mittnacht, M. Fanshawe, and S. Konstadt Anesthetic Considerations in the Patient With Valvular Heart Disease Undergoing Noncardiac Surgery Seminars in Cardiothoracic and Vascular Anesthesia, March 1, 2008; 12(1): 33 - 59. [Abstract] [PDF]

				A. J. C. Mittnacht, C. Moung, and W. W. Lai Massive Cardiac Hypertrophy in a Patient with Danon Disease: An Intraoperative Transesophageal Echocardiographic Evaluation Anesth. Analg., October 1, 2007; 105(4): 963 - 965. [Full Text] [PDF]

				G. Parodi, S. Del Pace, C. Salvadori, N. Carrabba, I. Olivotto, G. F. Gensini, and for the Tuscany Registry of Tako-Tsubo Cardiomyopa Left Ventricular Apical Ballooning Syndrome as a Novel Cause of Acute Mitral Regurgitation J. Am. Coll. Cardiol., August 14, 2007; 50(7): 647 - 649. [Full Text] [PDF]

				A. Civelek, Z. Szalay, M. Roth, R. Arnold, W.-P. Klovekorn, P. R. Vogt, and E. P. Bauer Post-mitral valve repair systolic anterior motion produced by non-obstructive septal bulge Eur. J. Cardiothorac. Surg., December 1, 2003; 24(6): 857 - 861. [Abstract] [Full Text] [PDF]

				E. H. C. Yu, A. S. Omran, E. D. Wigle, W. G. Williams, S. C. Siu, and H. Rakowski Mitral regurgitation in hypertrophic obstructive cardiomyopathy: relationship to obstruction and relief with myectomy J. Am. Coll. Cardiol., December 1, 2000; 36(7): 2219 - 2225. [Abstract] [Full Text] [PDF]