1. Regional Myocardial Three-Dimensional Principal Strains During Postinfarction Remodeling 
James J. Pilla, PhD, Kevin J. Koomalsingh, MD, Jeremy R. McGarvey, MD, Walter R.T. Witschey, PhD, Larry Dougherty, PhD, Joseph H. Gorman, MD, Robert C. Gorman, MD 
The Annals of Thoracic Surgery 
Volume 99, Issue 3, Pages (March 2015)
DOI: /j.athoracsur
Copyright © 2015 The Society of Thoracic Surgeons Terms and Conditions

2. Fig 1
Coordinate system of principal strain vectors. (A) Radial-circumferential angle (θRC) is the principal strain vector projected on the radial-circumferential plane. Analogous descriptions are used for the (B) radial-longitudinal (θRL) and (C) longitudinal circumferential (θCL) planes. (Circ = circumferential; Long = longitudinal.)
The Annals of Thoracic Surgery  , DOI: ( /j.athoracsur )
Copyright © 2015 The Society of Thoracic Surgeons Terms and Conditions

3. Fig 2
Tagged images of left ventricular remodeling after myocardial infarction. Short-axis midventricular images acquired at baseline (left), 1 week (middle), and 4 weeks (right) after infarct. (Top row) End diastole (ED) images show the change in left ventricle size and geometry with infarct progression. (Bottom row) Regional tag deformation at end systole (ES) are shown for the three timepoints. Infarct region is delineated using markers, which create signal voids (arrows).
The Annals of Thoracic Surgery  , DOI: ( /j.athoracsur )
Copyright © 2015 The Society of Thoracic Surgeons Terms and Conditions

4. Fig 3
Regional maximum principal strain magnitude and angles during left ventricle remodeling. (A) Maximum principal strain magnitude (E1Mag) is altered in all regions as the ventricle remodels. Infarct (INF) has the greatest change in E1Mag, decreasing at 1 week, then increasing at 4 weeks. Maximum principal strain angles (B) E1θRC, (C) E1θRL, and (D) E1θCL were unchanged in the remote (REM) region. Infarct and border zone (BZ) angles rotated away from the radial direction to a more circumferential-longitudinal direction, indicating stretch. +p < 0.05 versus baseline; ‡p < 0.05 versus 1 week; *p < 0.05 versus remote; •p < 0.05 versus BZ. (Black bars = baseline; dark gray bars = 1 week; light gray bars = 4 weeks.)
The Annals of Thoracic Surgery  , DOI: ( /j.athoracsur )
Copyright © 2015 The Society of Thoracic Surgeons Terms and Conditions

5. Fig 4
Regional minimum principal strain magnitude and angles during left ventricle remodeling. (A) At 1 week, minimum principal strain magnitude (E3Mag) decreases in all regions but increases as remodeling continues. Remote (REM) improvement could be attributed to left ventricle compensation whereas border zone (BZ) and infarct (INF) increase is probably a consequence of tissue stretch. Angles (B) E3θRC, (C) E3θRL, and (D) E3θCL are altered in all regions, which may be attributed to both changes in infarct and BZ tissue properties and decreased left ventricular torsion. +p < 0.05 versus baseline; ‡p < 0.05 versus 1 week; *p < 0.05 versus remote; •p < 0.05 versus BZ. (Black bars = baseline; dark gray bars = 1 week; light gray bars = 4 weeks.)
The Annals of Thoracic Surgery  , DOI: ( /j.athoracsur )
Copyright © 2015 The Society of Thoracic Surgeons Terms and Conditions

6. Fig 5
Bulls-eye plots of (A) maximum principal strain (E1Mag) and (B) minimum principal strain (E3Mag) at baseline, 1 week (1-Wk), and 4 weeks (4-Wk) after infarct (INF) for a representative animal. Plots display three midventricular slices from apex (inner) to base (outer) for remote (REM), border zone (BZ), and infarct (INF) regions. The E1Mag decreases in all regions at 1 week but increases at 4 weeks in the infarct. Infarct E1 vectors (E1θRC, E1θRL) shift from radial direction at baseline to more circumferential-longitudinal, signifying decreased wall thickening and increased tissue stretch. Circumferential shortening (E3Mag) decreases in all regions as the left ventricle remodels, whereas infarct E3 vectors (E3θRC, E3θRL) shift from circumferential-longitudinal to a more radial direction, indicating tissue stretch.
The Annals of Thoracic Surgery  , DOI: ( /j.athoracsur )
Copyright © 2015 The Society of Thoracic Surgeons Terms and Conditions

7. Fig 6
Regional intermediate principal strain magnitude and angles during left ventricle remodeling. (A) Contrasting maximum strain magnitude (E1Mag) and minimum strain magnitude (E3Mag), the regional magnitude of E2 (E2Mag) varies significantly with location before infarction (INF). (B) After infarction, E2θRC is altered at 4 weeks, with little change in the remote (REM) and border zone (BZ). (C) The E2θRL is decreased at 1 week and 4 weeks after myocardial infarction. (D) E2θCL decreases in REM and BZ as LV remodels while INF remains elevated above baseline at 1 week and 4 weeks. +p < 0.05 versus baseline; *p < 0.05 versus REM; •p < 0.05 versus BZ. (Black bars = baseline; dark gray bars = 1 week; light gray bars = 4 weeks.)
The Annals of Thoracic Surgery  , DOI: ( /j.athoracsur )
Copyright © 2015 The Society of Thoracic Surgeons Terms and Conditions