A saddle-shaped annulus reduces systolic strain on the central region of the mitral valve anterior leaflet  Jorge H. Jimenez, PhD, Shasan W. Liou, BSc, Muralidhar Padala, BSc, Zhaoming He, PhD, Michael Sacks, PhD, Robert C. Gorman, MD, Joseph H. Gorman, MD, Ajit P. Yoganathan, PhD  The Journal of Thoracic and Cardiovascular Surgery  Volume 134, Issue 6, Pages 1562-1568 (December 2007) DOI: 10.1016/j.jtcvs.2007.08.037 Copyright © 2007 The American Association for Thoracic Surgery Terms and Conditions

Figure 1 A, Schematic of the Georgia Tech Physiological Left Heart Simulator and its different components. B, Diagram of the marker array used for the leaflet strain experiments. C, Dual-camera photogrammetric images of the mitral valve and the ink marker array. The Journal of Thoracic and Cardiovascular Surgery 2007 134, 1562-1568DOI: (10.1016/j.jtcvs.2007.08.037) Copyright © 2007 The American Association for Thoracic Surgery Terms and Conditions

Figure 2 A, Plots of the major and minor principal strains during the systolic phase of the cardiac cycle for a typical porcine mitral valve. B, Average major and minor principal strains for the 8 valves studied during the systolic phase of the cardiac cycle. Bars represent 1 standard deviation. The Journal of Thoracic and Cardiovascular Surgery 2007 134, 1562-1568DOI: (10.1016/j.jtcvs.2007.08.037) Copyright © 2007 The American Association for Thoracic Surgery Terms and Conditions

Figure 3 A, Plot of transmitral pressure against average areal strain (n = 8) for the valves in the normal annular configuration. Error bars represent 1 standard deviation. B, Loading and unloading strain curves for typical mitral valve under physiologic conditions. Hysteresis is observed because the loading and unloading paths are different. The Journal of Thoracic and Cardiovascular Surgery 2007 134, 1562-1568DOI: (10.1016/j.jtcvs.2007.08.037) Copyright © 2007 The American Association for Thoracic Surgery Terms and Conditions

Figure 4 A, Average peak major principal strain for the different annular configurations. B, Average peak minor principal strain for the different annular configurations. C, Average peak areal strain for the different annular configurations. Paired t tests were used for statistical comparisons. Bars represent 1 standard deviation. The Journal of Thoracic and Cardiovascular Surgery 2007 134, 1562-1568DOI: (10.1016/j.jtcvs.2007.08.037) Copyright © 2007 The American Association for Thoracic Surgery Terms and Conditions