HEMODYNAMIC ASSESSMENT: CARDIAC CATHETERIZATION LABORATORY William Hellenbrand MD Director, Pediatric Cardiology Morgan Stanley Children’s Hospital of New York - Presbyterian Columbia University Medical Center Komansky Center for Children’s Health Cornell University Medical Center

CARDIAC CATHETERIZATION Cardiac output Shunt & Resistance Oxygen transport Pressure-Volume loops

FICK PRINCIPLE The amount of flow through an organ or any circuit may be determined if 1 - that organ consumes or secrets a given substance 2 - the concentration of that substance can be measured as it enters and leaves the organ 3 - The total amount of the substance consumed or secreted can be measured per unit time ∆S/∆t C2S – C1S

FICK PRINCIPLE

OXYGEN IN BLOOD When oxygen is exposed to blood it exists in 2 forms Bound to hemoglobin Each gram of Hgb is capable of binding 1.36 ml O2. Therefore if the Hgb is 15 gm/100ml then the maximal amount of oxygen(Capacity) that can be taken up by Hgb is 20.4 ml/100ml(Vol%)

OXYGEN IN BLOOD When oxygen is exposed to blood it exists in 2 forms(cont) In solution in plasma – At body temperature of 370 , there is .00003 ml of O2 per one ml of plasma at a partial pressure of oxygen of 1 mm Hg(1 torr) Thus the solubility coefficient of oxygen in plasma is 0.00003 ml/ml/mm Hg Therefore the amount of dissolved oxygen in plasma is equal to .003(PO2)

OXYGEN IN BLOOD Oxygen capacity = Hgb(gm/100ml)*1.36 ml O2/gm = ml O2/100ml (Vol%) Oxygen saturation = proportion of O2 actually combined with hemoglobin to the total capacity Oxygen content = Capacity*Saturation + .003*PO2 = ml/100ml (Vol%)

OXYGEN CONSUMPTION VO2 = VIFIO2 - VEFEO2 If RER is 1 then VI = VE and all you need to measure is VEFEO2 RER = VCO2 / VO2 RER is close to 1 with carbohydrate metabolism RER may be as low as 0.7 with mostly fat metabolism Standard nomograms assume RER of 0.9

Oxygen Consumption

CARDIAC OUTPUT SYSTEMIC BLOOD FLOW Qp = VO2 CpvO2 - CpaO2 Qs = VO2 CaoO2 - CmvO2 If there is no shunt Qp = Qs

SHUNT CALCULATIONS Qs = VO2 CaoO2 - CmvO2 Qp = VO2 CpvO2 - CpaO2 Qep = VO2 CpvO2 - CmvO2

SHUNT CALCULATIONS SIMPLE SHUNT BIDIRECTIONAL SHUNT Ql-r = Qp - Qs Qr-l = Qs - Qp BIDIRECTIONAL SHUNT Ql-r = Qp - Qep Qr-l = Qs - Qep

RESISTANCE TO FLOW Q Q = ∆Pπr4 1 = 8nl R πr4 8nl R = ∆P Poiseuille equation Q = ∆Pπr4 1 = 8nl R ∆P = pressure drop r = radius Q = ∆P n = viscosity R l = length of tube πr4 8nl R = ∆P Q

RESISTANCE SVR = AO(MEAN) - RA(MEAN) Qs PVR = PA(MEAN) - LA(MEAN) Qp

SYSTEMIC OXYGEN TRANSPORT (SOT) SOT = Q X OXYGEN CONTENT SOT = Q X [(1.36 X Hgb X O2 SAT) + (.003 X PO2)]

SYSTEMIC OXYGEN TRANSPORT (SOT) SOT = Q X [(1.36 X Hgb X O2 SAT) + (.003 X PO2)] Anemic Hypoxia:  Hgb SOT  Acute compensation  Q SOT  Chronic compensation  Hgb SOT 

SYSTEMIC OXYGEN TRANSPORT (SOT) SOT = Q X [(1.36 X Hgb X O2 SAT) + (.003 X PO2)] Hypoxic Hypoxia:  02 SAT SOT  Acute compensation  Q SOT  Chronic compensation Hgb,  Q SOT 

SYSTEMIC OXYGEN TRANSPORT (SOT) SOT = Q X [(1.36 X Hgb X O2 SAT) + (.003 X PO2)] Stagnant Hypoxia:  Q SOT  (Low Cardiac Output) Compensation  Hgb,  02 SAT SOT 

VSD 80/50 M=65 95 80/40 M=60 80 70 80 M=8 M=6 70 80/6 85

VSD Room Air Hgb = 10.0 Vol% V02 = 150 ml/min/m2 Saturations Pressures Svc = 70 Ra = 70 Rv = 85 Pa = 80 Ao = 95 Pressures Ra = 6(mean) Rv = 80/6 Pa = 80/40 60(mean) La = 8(mean) Ao = 80/50 65(mean)

VSD Room Air S(a-v)02 difference = 3.4 Capacity = 1.36*10 = 13.6 Contents = Ao =13.6*.95=12.9 Mv = 13.6*.70=9.5 Pa = 13.6*.80=10.9 Pv = 13.6*.95=12.9 S(a-v)02 difference = 3.4 P(a-v)02 difference = 2.0 Qp = 150/2.0 = 7.5 l/min/m2 Qs = 150/3.4 = 4.4 l/min/m2 Ql-r = 7.5-4.4=3.1 Qp/Qs = 7.5/4.4=1.7 PVR =(60-8)/7.5 =6.9 SVR =(65-6)/4.4=13.4

VSD fI02 = 1.0 Hgb = 10.0 Vol% V02 = 150 ml/min/m2 Saturations Svc = 75 (45) Ra = 80 Rv = 94 Pa = 95 (85) Ao = 100 (600) Pressures Ra = 6(mean) Rv = 80/6 Pa = 80/40 60(mean) La = 8(mean) Ao = 80/50 65(mean)

VSD fI02 = 1.0(PO2 not included) Capacity = 1.36*10 = 13.6 Contents = Ao =13.6*1.0=13.6 Mv = 13.6*.75=10.2 Pa = 13.6*.95=12.9 Pv = 13.6*1.0=13.6 S(a-v)02 difference = 3.4 P(a-v)02 difference = 0.7 Qp = 150/0.7 = 21.4 l/min/m2 Qs = 150/3.4 = 4.4 l/min/m2 Ql-r = 21.4-4.4=17.0 Qp/Qs =21.4/4.4=>4/1 PVR =(60-8)/21.4 =2.4 SVR =(65-6)/4.4=13.4

VSD fI02 = 1.0(PO2 included) S(a-v)02 difference = 5.0 Capacity = 1.36*10 = 13.6 Contents = Ao =13.6*1.0+1.8=15.4 Mv = 13.6*.75+.15=10.4 Pa = 13.6*.95+.25=13.2 Pv = 13.6*1.0+1.8=15.4 S(a-v)02 difference = 5.0 P(a-v)02 difference = 2.2 Qp = 150/2.2 = 6.8 l/min/m2 Qs = 150/5.0 = 3.0 l/min/m2 Ql-r = 6.8-3.0=3.8 Qp/Qs = 6.8/3.0=2.3 PVR =(60-8)/6.8 =7.6 SVR =(65-6)/3.0=20.0

VSD P02 not included Qp = 150/0.7 = 21.4 l/min/m2 Qs = 150/3.4 Ql-r = 21.4-4.4=17.0 Qp/Qs =21.4/4.4=>4/1 PVR =(60-8)/21.4 =2.4 SVR =(65-6)/4.4=13.4 P02 included Qp = 150/2.2 = 6.8 l/min/m2 Qs = 150/5.0 = 3.0 l/min/m2 Ql-r = 6.8-3.0=3.8 Qp/Qs = 6.8/3.0=2.3 PVR =(60-8)/6.8 =7.6 SVR =(65-6)/3.0=20.0

VALVE AREA CALCULATION

VALVE AREA CALCULATION

VALVE AREA CALCULATION

OXYGEN DISSOCIATION CURVE

OXYGEN DISSOCIATION CURVE

OXYGEN DISSOCIATION CURVE

PRESSURE-VOLUME LOOPS

P-V LOOPS

P-V LOOPS Pump Failure

P-V LOOPS Pump Failure

P-V LOOPS