1. The effect of regional ischemia on mitral valve annular saddle shape
Joseph H Gorman, MD, Benjamin M Jackson, MD, Yoshiharu Enomoto, MD, Robert C Gorman, MD 
The Annals of Thoracic Surgery 
Volume 77, Issue 2, Pages (February 2004)
DOI: /S (03)

2. Fig 1
The relationship of the sonomicrometry transducers, annular anatomy, coronary anatomy, and ischemic region: The nomenclature for the transducers is as follows: AC = anterior commissure; AO = aortic; PC = posterior commissure; P1 = anterior portion of mural annulus; P2 = mid portion of mural annulus; and P3 = posterior portion of mural annulus. OM2 and OM3 mark the second and third obtuse marginal branches of the circumflex coronary artery, respectively. PDA marks the posterior descending coronary artery. Note that transducers P2, P3, and PC are most closely associated with the ischemic region. Also note that AC and AO are closely related to the anterior and posterior trigones of the heart's fibrous skeleton, respectively.
The Annals of Thoracic Surgery  , DOI: ( /S (03) )

3. Fig 2
Image of a normal ovine mitral annulus at end systole: a three-dimensional (3D) surface has been fit using the 3D coordinates of six annular sonomicrometry transducers. The surface is not meant to represent the leaflets but rather to allow visualization of the 3D shape of the annulus. Note the saddle shape. Again, the nomenclature for the transducers is as follows: AC = anterior commissure; Ao = aortic; H = annular height; PC = posterior commissure; P1 = anterior portion of mural annulus; P2 = mid portion of mural annulus; P3 = posterior portion of mural annulus; W = intercommissural distance. (A) Annulus as viewed from posterior annulus to aorta. (B) Annulus as viewed from anterior to posterior commissure. Also illustrated is the definition of the annular height to commissural width ratio (AHCWR), a parameter used to quantify the degree of mitral annular nonplanarity. The shading of the images represents the vertical displacement of the transducers and surface relative to a best fit annular reference plane; lighter shading represents points closer to the ventricular apex.
The Annals of Thoracic Surgery  , DOI: ( /S (03) )

4. Fig 3
Changes in annular height to commissural width ratio (AHCWR) throughout the cardiac cycle before (black circles) and during (white circles) ischemia causing acute ischemic mitral regurgitation (AIMR). Each graph represents an average of the same six animals. Differences in AHCWR were compared for all four portions of the cardiac cycle individually using one-way analysis of variance (ANOVA). During ischemia AHCWR was found to be significantly different (p < 0.05) during isovolemic contraction, ejection, and isovolemic relaxation, but not during diastolic filling. Within the portions of the cardiac cycle found to be significantly different by ANOVA each time point was compared using paired Student's t test. Each significantly different time point (p < 0.05) is marked with a white or black dot. Note that the normal systolic accentuation of the saddle shape (increasing AHCWR) is eliminated during ischemia and AIMR. (EIVC = end isovolemic contraction; EIVR = end isovolemic relaxation; and ES = end systole. End diastole is defined as time = 0.)
The Annals of Thoracic Surgery  , DOI: ( /S (03) )

5. Fig 4
End-systolic images of a representative ovine mitral annulus before and after a posterior ischemia causing acute ischemic mitral regurgitation (AIMR). Images were constructed as in Fig 2. Note the relative flattening of the posterior annulus near the posterior commissure (darker shading) during ischemia. (AC = anterior commissure; Ao = aortic; PC = posterior commissure; P1 = anterior portion of mitral annulus; P2 = mid portion of mitral annulus; P3 = posterior portion of mitral annulus.)
The Annals of Thoracic Surgery  , DOI: ( /S (03) )

6. Fig 5
Average changes in mitral annular height to commissural width ratio (AHCWR) throughout the cardiac cycle in nine humans with normally functioning valves (black circles) and 8 patients with chronic ischemic mitral regurgitation (MR) of varying degrees (white circles). This figure was constructed from data in reference 13. The AHCWR values were not presented in the paper but annular height and intercommissural distance were reported. All cardiac cycles are normalized to ten systolic and ten diastolic time points. Note the systolic accentuation of the saddle shape in humans similar to that seen in sheep. In addition chronic ischemic MR in humans seems to be associated with loss of the systolic increase in AHCWR as in our acute ischemic MR model.
The Annals of Thoracic Surgery  , DOI: ( /S (03) )