Systemic Vascular Resistance


  • SVR is calculated from the Cardiac Output (CO) (or Cardiac Index (CI)) and the right atrial pressure (RAP) (or Central venous pressure (CVP).
  • Estimate CVP/RAP.
  • Small underfilled heart (5), normal (10) , enlarged IVC with full RA/RV (15).
  • Using 10 is acceptable in most cases, just trying to get an estimate of SVR.


SVR (dynes⋅sec⋅cm-5) = 80 x [MAP-RAP] (mmHg) / CO (L/min)

SVRI = 80 x (MAP-RAP)/CI

  • Normal: 900-1200
  • Vasodialted: 400-900
  • Vasoconstricted: >1200


Will be incorrect if the CO measurement is inaccurate.

Should be understood as a semi-quantitative estimation; vasodilated, normal or vasoconstricted.


American Society of Echocardiography Guidlines: Assessment of Structure and Function