TY - CHAP
M1 - Book, Section
TI - Appendix E. Measurements and Calculations
A1 - Mathew, Joseph P.
A1 - Swaminathan, Madhav
A1 - Ayoub, Chakib M.
PY - 2010
T2 - Clinical Manual and Review of Transesophageal Echocardiography, 2e
AB - Fractional shortening (%) =Velocity of circumferential fiber shortening (circ/sec) =fractional shortening × ejection timeFractional area change (%) =Ejection fraction (%) =Volume by Simpson's method of disks where the LV is modeled as a series of stacked cylindrical disks capped by an elliptical disk apexVolumecylindrical disks = (π × D1/2) × D2/2) × Hwhere D1 and D2 are orthogonal diameters of the cylinder, and H is the height of the cylinderandVolumeelliptical disk = Ah/2 + a2/b2 × π × h3/6where 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.Volume by the area-length method where the LV is modeled as acylinder–hemi-ellipsoidVolume = (5 × area × major-axis length)/6where the area is planimetered by using a short-axis view at the level of the mitral valveVolume by the diameter-length method where the LV is modeled as a prolate-ellipsoidVolume = (π × D1 × D2 × major-axis length)/6where D1 and D2 are orthogonal short-axis diametersStroke volume (ml) =(end-diastolic volume – end-systolic volume)Cardiac output (liters/min) = (stroke volume × heart rate)Cardiac index (liters/min/m2) =Meriodinal wall stresswhere P represents LV peak pressure, Ac is LV cavity area, and Am represents LV myocardial area (area of the muscle in the short-axis view)Circumferential wall stresswhere L represents the LV long-axis lengthStrain (%) =where length0 is the initial lengthStrain rate (s–1) =LV mass (g) =(1.04 × [(LVID + PWT + IVST)3 – LVID3]) × 0.8 + 0.6dP/dt (mm Hg/s) =32 × 1000/dtwhere dt (in msec) is the time for velocity to rise from 1 m/s to 3 m/s on a continuous wave Doppler tracing of mitral regurgitationMyocardial performance index =
SN -
PB - The McGraw-Hill Companies
CY - New York, NY
Y2 - 2022/05/21
UR - accessanesthesiology.mhmedical.com/content.aspx?aid=6922062
ER -