Mitral Annular Dynamics in Myxomatous Valve Disease: New Insights With Real-Time 3-Dimensional Echocardiography

Circulation. 2010; 121(4):1423-1431

Jasmine Grewal, Rakesh Suri, Sunil Mankad, Akiko Tanaka, Douglas W. Mahoney, Hartzell V. Schaff, Fletcher A. Miller, Maurice Enriquez-Sarano

OBJECTIVES: Mitral annulus is a complex structure of poorly understood physiology. Full-volume real-time 3-dimensional transesophageal echocardiography offers a unique opportunity to completely image and quantify mitral annulus size and motion.

METHODS: Real-time 3-dimensional transesophageal echocardiography of the mitral valve was acquired in 32 patients with myxomatous valve disease (MVD) and moderate to severe regurgitation, 15 normal control subjects, and 10 patients with ischemic mitral regurgitation of identical body surface area. Mitral annulardimensions (circumference, area, anteroposterior and intercommissural diameters, height, and ratio of height to intercommissural diameter ratio, which appraises annular saddle-shape depth) were measured throughout the cardiac cycle with dedicated quantification software.

RESULTS: Compared with direct surgical measurement, 3-dimensional anterior annular dimension provided reliable measurements (mean difference, 0.1±0.1 mm; P=0.73; 95% confidence interval, ±4.4 mm). Annular dimensions were larger in MVD patients compared with control subjects in diastole (all P<0.05). Normal annulus displayed early-systolic anteroposterior (P<0.001) and area (P=0.04) contraction, increased height (P<0.001), and deeper saddle shape (ratio of height to intercommissural diameter, 15±1% to 21±1%; P<0.001), whereas intercommissural diameter was unchanged (P=0.30). In contrast, MVD showed early-systolicintercommissural dilatation (P=0.02) and no area contraction (P=0.99), height increase (P=0.11), or saddle-shape deepening (P=0.35). Late-systolic MVD annular saddle shape deepened but annular area excessively enlarged (P<0.04) as a result of persistent intercommissural widening (P<0.02). MVD annulus also contrasts with ischemic mitral regurgitation annulus, which, despite similar anteroposterior enlargement, is narrower and essentially adynamic. After MVD repair, the annulus remained dynamic without systolic saddle-shape accentuation (P=0.30).

CONCLUSIONS: Real-time 3-dimensional transesophageal echocardiography provides insights into normal, dynamic mitral annulus function with early-systolic area contraction and saddle-shape deepening contributing to mitral competency. MVD annulus is also dynamic but considerably different with loss of early-systolic area contraction and saddle-shape deepening despite similar magnitude of ventricular contraction, suggestive of ventricular-annulardecoupling. Subsequent area enlargement may contribute to mitral incompetence. After mitral repair, MVD annulus remains dynamic without systolic saddle-shape accentuation. Thus, real-time 3-dimensional transesophageal echocardiography provides new insights that allow the refining of mitral pathophysiology concepts and repair strategies.

PMID: 20231533

3 Responses

  1. Paul Schoenhagen, MD  on April 3rd, 2010

    Also see:
    Real-time three-dimensional transoesophageal echocardiography for guidance of non-coronary interventions in the catheter laboratory.
    Balzer J, Kelm M, Kühl HP.
    J Echocardiogr 2009;10:341-9.
    PMID: 19211569

  2. Jacobo Kirsch, MD  on April 16th, 2010

    Very interesting paper! The schematic representations of the mitral annulus (both normals and abnormal) are superb.

    A very interesting finding made by the authors is that after repair, the annular saddle shape did not change nor showed a return of physiological early saddle-shape deepening.

  3. Paul Schoenhagen  on August 10th, 2010

    See also:

    Anatomy of the Mitral Valvular Complex and Its Implications for Transcatheter Interventions for Mitral Regurgitation.
    Nicolas M. Van Mieghem, Nicolo Piazza, Robert H. Anderson, Apostolos Tzikas, Koen Nieman, Lotte E. De Laat, Jackie S. McGhie, Marcel L. Geleijnse, Ted Feldman, Patrick W. Serruys, and Peter P. de Jaegere.
    J Am Coll Cardiol 2010;56 617-626.


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