Cath Hemodynamics & Angiography Fundamentals Notes

Cath Hemodynamics & Angiography Fundamentals

Reporting Hemodynamics

Saturations

-SVC high & low

-RA, RV

-PA, LA/Pulm vns, LV,

-Ao

Pressures

-RA, RV

-MPA, LPA, RPA, PCWP

-LA, LV, asc Ao, desc Ao

double check to ensure your %sats and Pressures make sense!

Angiography

-type of angiogram (location, RAO, AP, etc)

-type of cath

-cath course (cath entering IVC then RA, w tip situated in RV)

-current projection (AP, lateral etc)

Determining Cardiac Output

CO = SV * HR

CI = (SV*HR)/BSA

Fick

CO = O2 consumption/ (A-VO2)

-O2 consumption can be measured directly or assumed. Units: mL/min/m²

-A-VO2 = Art Vn O2 difference in O2 content (e.g.g diff in %sats)

-O2 Content = (1.36*Hgb*%sat) + (0.003*PaO2)

-the dissolved O2 relative to Hgb-O2 increases as FiO2 increases,

so must include if pt on signif amt of FiO2

-CO = VO2/(Ao %sat - MV %sat)(Hgb*1.36*10)

-Resistance: Ohms Law V=IR --> delta P =QR

-PVR = (PA mean - PCWP/Qp)

-if multiple resistors are in series, you must add them: R_∑= R₁+ R₂+ R₃+ ...

-if multiple resistors are in parallel, add the inverses: 1/R_∑= 1/R₁+ 1/R₂+ 1/R₃+ ...

**for mixed venous sats, use the most distal chamber prior to teh step-up. (though bn SVC adn RA might have up to 5% step up, still WNL bc renal vn less desaturated than SVC)

Equations

O2 solubility coefficient = 0.03mL/mmHg/liter blood

O2 capacity mLO2/liter blood = (Hgb g/dL)(1.36 mLO2/g*Hgb)(10dL/L)

dissolved O2 is 0.03mL/mmHg/Liter blood

max O2 capacity is 1.36mLO2/gm of Hgb

O2 capacity thus is the Hgb amt * 1.36 (*10 for unit correction)

O2 Content = (1.36*Hgb*%sat) + (0.03*PaO2)

Qs = VO2 mLO2/ (1.36*10 mLO2/gHgb/L)(Hgb g/dL)(Ao-SVC %O2)

Qp = VO2 mLO2/ (1.36*10 mLO2/gHgb/L)(Hgb g/dL)(PV-PA %O2)

Qp/Qs = systemic AV diff/pulm AV diff = (Ao-SVC %)/(PV-PA %)

Qep - Q effective pulmonary = VO2 mLO2/ (1.36*10 mLO2/gHgb/L)(Hgb g/dL)(PV-SVC%O2)

PVR Wu*m2 = (PAPmean - LAP mean)/Qp

SVR Wu*m2 = (AoPmean - RAPmean)/Qs

Wood units = mmHg/L/min

Pressure Tracings

Atrial Pressures