Appendix E: Measurements and Calculations

LEFT VENTRICLE

1. $Fractional shortening(%)=(end-diastolic diameter)−(end-systolic diameter)(end-diastolic diameter)×100$

2. Velocity of circumferential fiber shortening (circ/s) = fractional shortening ×1/ ejection time

3. $Fractional area change(%)=(end-diastolic area)−(end-systolic area)(end-diastolic area)×100$

4. Fractional area change corrected for afterload

   $(FAC afterload corrected(FACac)=FAC×log([MAP-RAP]/CI)×100%)$

5. $Ejection fraction(%)=(end-diastolic volume)−(end-systolic volume)(end-diastolic volume)×100$

6. Volume by Simpson method of disks where the LV is modeled as a series of stacked cylindrical disks capped by an elliptical disk apex

   $Volumecylindrical disks=(π×D12)×D22)×H$

   where D₁ and D₂ are orthogonal diameters of the cylinder, and H is the height of the cylinder

   and

   $Volumeelliptical disk=Ah2+a2b2×π×h36$

   where A is the area of the ellipsoid segment, h is the height of the ellipsoid segment, and a and b are radii of the total ellipsoid.

7. Volume by the area-length method where the LV is modeled as a cylinder–hemi-ellipsoid

   $Volume=(5×area×major-axislength)6$

   where the area is planimetered by using a short-axis view at the level of the mitral valve

8. Volume by the diameter-length method where the LV is modeled as a prolate-ellipsoid

   $Volume=(π×D1×D2×major-axis length)6$

   where D1 and D2 are orthogonal short-axis diameters

9. Stroke volume (ml) = (end-diastolic volume – end-systolic volume)

10. Cardiac output (liters/min) = (stroke volume × heart rate)

11. Cardiac index (liters/min/m²) =

    $(stroke volume×heart ratebody surface area)$

12. Meriodinal wall stress

    $σm=1.33×P(Ac/Am)×103dyne/cm2$

    where P represents LV peak pressure, A_c is LV cavity area, and A_m represents LV myocardial area (area of the muscle in the short-axis view)

13. Circumferential wall stress

    $σc=[(1.33PAc)(Am+Ac−Ac)]×[4AcAc/πL2(Am+Ac−Ac)]dyne/cm2$

    where L represents the LV long-axis length

14. Preload-Adjusted Maximal Power index =

    $Integrated Area within Pressure-Area Loop(End-Diastolic Area)3/2$

15. Strain (%) =

    $length−length0length0$

    where length₀ is the initial length

16. Strain rate (s⁻¹) =

    $straintime$

17. $Strain Rate≅Velocitya−VelocitybDistance$

18. LV mass (g) =

    $(1.04×[(LVID+PWT...$