TY  - CHAP
M1  - Book, Section
TI  - Measurements and Calculations
A1  - Mathew, Joseph P.
A1  - Nicoara, Alina
A1  - Ayoub, Chakib M.
A1  - Swaminathan, Madhav
PY  - 2018
T2  - Clinical Manual and Review of Transesophageal Echocardiography, 3e
AB  - Fractional  shortening(%)=(end-diastolic  diameter)−(end-systolic  diameter)(end-diastolic  diameter)×100Velocity  of  circumferential  fiber  shortening  (circ/s)  =  fractional  shortening  ×1/  ejection  timeFractional  area  change(%)=(end-diastolic  area)−(end-systolic  area)(end-diastolic  area)×100Fractional  area  change  corrected  for  afterload(FAC  afterload  corrected(FACac)=FAC×log([MAP-RAP]/CI)×100%)Ejection  fraction(%)=(end-diastolic  volume)−(end-systolic  volume)(end-diastolic  volume)×100Volume  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)×Hwhere  D1  and  D2  are  orthogonal  diameters  of  the  cylinder,  and  H  is  the  height  of  the  cylinderandVolumeelliptical  disk=Ah2+a2b2×π×h36where  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  a  cylinder–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)  =(stroke  volume×heart  ratebody  surface  area)Meriodinal  wall  stressσm=1.33×P(Ac/Am)×103dyne/cm2where  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  stressσc=[(1.33PAc)(Am+Ac−Ac)]×[4AcAc/πL2(Am+Ac−Ac)]dyne/cm2where  L  represents  the  LV  long-axis  lengthPreload-Adjusted  Maximal  Power  index  =Integrated  Area  within  Pressure-Area  Loop(End-Diastolic  Area)3/2Strain  (%)  =length−length0length0where  length0  is  the  initial  lengthStrain  rate  (s−1)  =straintimeStrain  Rate≅Velocitya−VelocitybDistanceLV  mass  (g)  =  (1.04×[(LVID+PWT+IVST)3−LVID3])×0.8+0.6  gdP/dt  (mm  Hg/s)  =  32  ×  1000/dtwhere  dt  (in  ms)  is  the  time  for  velocity  to  rise  from  1  to  3  m/s  on  a  continuous-wave  Doppler  tracing  of  mitral  regurgitationMyocardial  performance  index  =(isovolumic  contraction  time+isovolumic  relaxation  time)(ejection  time)  
SN  - 
PB  - McGraw-Hill Education
CY  - New York, NY
Y2  - 2024/04/16
UR  - accessanesthesiology.mhmedical.com/content.aspx?aid=1195104639
ER  -