Cardiac Catheterizations - Cao Việt Tùng

CARDIAC CATHETERIZATIONS 
 Cao Việt Tùng. MD 
National Hospital of Pediatrics 
Part I 
Basic concept 
Indications 
Diagnostic 
Intervention 
Which Catheter should be used ? 
• End hole catheter- to measure wedged 
pressures and to precisely localized gradients 
• Side hole catheters - for angiography prevent 
clot/tissue obstruction during pressure 
measurement 
Type of catheter 
Size of catheter 
Patient weight Catheter size (PG) 
2-4 kg 4 F 
3-10 kg 4F 
8-20 kg 5F 
15-20 kg 6F 
30-60 kg 7F 
50-90 kg 8F 
HOW MUCH CONTRAST 
Chamber/
vessel 
Normal size 
(cc/kg) 
Increase volume, 
normal flow 
(cc/kg) 
Marked 
increase. 
Volume & 
flow 
Aorta 
LV 
LA 
PA 
RV 
RA 
1.0 
1.2 
1.0 
1.0 
1.2 
1.0 
1.5 
2.0 
1.5 
1.2 
2.0 
1.5 
1.8 
2.5 
2.0 
1.5 
2.5 
2.0 
Part II 
Hemodynamic 
Normal pressure & Saturation 
RA m=3mmHg 
RV: 25/3 mmHg 
 LA: Mean=8 mmHg 
LV: 100/ 8 mmHg 
75% 
75% 
75% 
75% 
98% 
98% 
98-99% 
98-99% 
75 
Ao: 100/ 60 (75)mmHg 
PV 
PA: 25/10 (15)mmHg 
SVC 
PRESSURE – VOLUME LOOP 
RA 
• Increase ‘a’: 
• PS, PA, PHT 
• Non compliance RV:- RVH 
• Large ‘v’ : 
• TR, Ebstein’s anomaly, 
• Left ventricular to right atrial shunt 
RV 
• Peak systolic pressure is less than 30mmHg and EDP 
is less than 7mmHg (represents peak ‘a’ wave in right 
atrium) 
• Increase RV pressure: 
 PHT 
 RVOT obstruction 
PA 
• Increase PA pressure: 
– Peripheral PA stenosis 
– Pulmonary venous or arteriolar obstruction 
– Left atrial hypertension 
– LV failure 
– PHT 
PA - RV 
• Systolic gradient between the RV and PA :(gradient up 
to 10mmHg may be normal) 
• RVOT obstruction 
• Gradients up to 30-40mmHg may be seen with 
structurally normal PV but increase blood flow i.e. 
large ASD 
WEDGE PRESSURE 
• Obtained by “wedging” an end hole catheter in 
a distal PA, good reflection of the downstream 
pressure i.e. LA pressure, LVED 
• PA wedge Pressure= LA pressure 
• PV Wedge pressure= PA pressure 
LA 
• LA 
 same waves as RA 
 mean LA pressure is normally higher 
 ‘v’ wave is higher than ‘a’ wave - caused by pulmonary 
vein contraction 
 ‘v’ even higher when measured in PV’s 
LV 
• Early diastolic pressure (EDP) should be at or near 
zero 
• Longer , flatter plateau phase at maximum systolic 
pressure 
LV 
 • EDP can be as high as 10-12mmHg in children 
• Increased EDP: 
– Heart failure 
– Restrictive pericardial 
– Myocardial disease 
– Large left to right shunt 
INTRACARDIAC SHUNT 
• An increase saturation in between different sites in 
right heart suggest presence and magnitude of left to 
right shunt 
• Decrease saturation in between different sites in left 
heart suggest presence and magnitude of right to left 
shunt 
• A step up of less than 6% at atrial level, 4% at 
ventricular level and 4% at great vessel level – can be 
consider as normal 
RA 
 • Step up of more than 9% is highly suggestive of Left 
to right shunt: 
– ASD with or without mitral valve disease 
– Left ventricular to right atrial shunt 
– VSD defect with TR 
– Coronary AV fistula 
– Ruptured sinus valsava into RA 
RV 
 • Step up of more than 6% suggest of left to right shunt 
– Low ASD level 
– VSD defect 
– Coronary AV fistula 
– Ruptured sinus valsava into RV 
PA 
 • Step up of more than 6% at Pulmonary suggest of left 
to right shunt: 
– High VSD 
– PDA 
– AP window 
– Anomalous origin of CA to PA 
RIGHT TO LEFT SHUNT 
• Suspicious if 
 the aortic saturation is <95% or 
 2% or greater step between LA/LV and aorta 
LA 
 • Desaturation in LA: right to left shunt through ASD 
or PFO in: 
– TA/stenosis 
– PA 
– Severe PS 
– Severe vascular disease 
SHUNT CALCULATION 
Flow (L/min/m2) 
• Pulmonary blood flow (Qp) 
• Systemic blood flow (Qs) 
SHUNT CALCULATION 
Qp = VO2 
 (PV sat - PA sat)(Hgb)(1.34)(10) 
Qs = VO2 
 (Ao sat - SVC sat)(Hgb)(1.34)(10) 
SHUNT CALCULATION 
• Shunt ratio 
• MV (mixed vein): 
• (3 SVC + IVC )/4 
• (SVC + 2IVC) /3 
• PV ( Pulmonary vein) : 
• assumed 98% or LA/LV/aortic if no R to L shunt 
Need to get saturation for: 
 Aorta 
 IVC (high and low) 
 SVC (high and low) 
 PA 
 PV 
SHUNT CALCULATION 
 • Normal ratio of Qp/Qs=1 
• In left to right shunt, increase pulmonary blood flow 
the ratio increase 
SHUNT CALCULATION 
 • On oxygen: VO2 150 ml; Hb 15g; MV 70%, SA 
98%; PV 100%; PA 95%; pO2 (mmHg) MV 40, SA 
500, PV 600, PA 80 
Qp/Qs = 5.8/2.1 = 2.7/1 
PVR and SVR 
 • PVR= (PA mean - LA mean) / Qp 
(Normal PVR: 1-3 wood) 
• SVR= (Mean Ao - Mean RA) / Qs 
 (Varies 15-30 unit.m2) 
• Rp:Rs= 1: 10 To calculate PVR: 
Mean PA/LA/RA 
Qp and Qs 
PVR and SVR 
• O2, inhaled NO, IV or nebulized prostacyclin 
• What is positive response? 
– Reduction of mean PAP & PVR > 20%? 
– Acute reduction of the mean PAP of > 10 mm 
Hg with a resultant mean PAP of 40mmHg or 
less without a fall in cardiac output is 
considered a positive vasoreactivity response.