This document provides an overview of right heart catheterization (RHC) in children. It begins with a brief history of RHC, describing early experiments in the 1840s-1920s. The document then covers patient preparation, venous access approaches, conducting the procedure, normal pressure values, shunt detection/quantification using oximetry, and understanding Fick's principle. The key objectives are to gain knowledge on performing tailored RH studies, the diagnostic role of RHC, and quantifying left-to-right shunts.
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PRINCIPLES AND PRACTICES OF RIGHT HEART CATHETERIZATION IN CHILDREN
1. MURTAZA KAMAL
MBBS, MD, DNB
RESIDENT DNB-SS (PEDIATRIC CARDIOLOGY)
MURTAZA.VMMC@GMAIL.COM
DOP: 5-7/12/2017
PRINCIPLES AND
PRACTICES OF RIGHT
HEART
CATHETERISATION
IN CHILDREN
1
2. OBJECTIVESâĻ
ī Gain an overview of history and development of
RHC
ī Learn how to perform a RH study tailored to
answer a specific clinical question
ī Gain a better understanding of role of RHC as a
diagnostic tool in specific situations
2
3. CLAUDE BERNARD
ī 1844: France
ī 1st RHC on horse
ī Inserted glass tubes via
jugular vein and carotid
artery
ī Measured temperature
in both ventricles
ī Later measured
intracardiac pressures
too
Nossaman BD et al. H/o RHC: 100 years of experimentation and methodology development. Cardiol Rev 2010;18:94-101. 3
4. WERNER FORSSMANN
ī 1929; Germany
ī Self catheterization
using urethral catheter
ī Used lt. anticubital
veinī RV; (X-RAY)
ī Against medical ethics
Meyer JA. W Forssmann and catheterisation of the heart, 1929.
Ann Thorac Surg 1990;49:497-9
4
6. INTRODUCTION
ī With advent of non-invasive modalities (ECHO,
MRI): Cardiac catheterization has reduced
dramatically
ī Gold standard: For assessment of cardiac
hemodynamics
ī Resolves discrepancy b/w c/fs and non-invasive
measurements
6
7. INTRODUCTION CONTâĻ
ī Perform through review of clinical history,
physical exam, ECG, CXR, ECHO, MRI(+/-)
before patient enters cath lab
ī Why is the study being performed?
ī If results are not going to alter the course of
management: Best not to perform
ī Have a clear idea as what is the data one
wishes to seek
ī Wild goose chase: More questions than
answers 7
8. CONDUCT OF A CATHETERIZATION STUDY
ī Proper study needs adherence to standard
protocols
ī Due attention to be given to pressure
recordings and saturation assessments
ī Flexibility is approach needed: Each case is
different
8
9. PATIENT PREPARATION
ī The parents must be informed of indication and
risks of procedure
ī Retrospective and prospective data revealed:
Serious adverse event: 1.1%
Mortality: 0.05%
Hoeper M et al. Complications of RHC procedures in patients with PH in experienced centers. J Am Coll Cardiol 2006;48: 2546-52
9
10. PATIENT PREPARATION CONTâĻ
ī MC complications:
Access site hematoma
Vagal reaction
Pneumothorax
Arrhythmias
ī If available: Quote individual/ departmental
complications
10
11. PATIENT PREPARATION
ī Rule out anemia, infections, thrombocytopenia
ī Electrolyte/ metabolic disturbances
ī Dehydration
ī Digoxin toxicity
ī Coagulopathy
Safe in patients with INR <3.5 undergoing
RHC via IJV or anti cubital veins
Ranu H et al. A retrospective review to evaluate the safety of RHC via IJV in assessment of PH.. Clin Cardiol 2010;33: 303-6
11
12. OUR HOSPITAL PROTOCOL
ī Obtain cath profile and PAC clearance before
admission (1 day prior)
ī NBM: 4 hours before
ī Caution: OVERZELOUS FASTING PROTOCOLS
MAY LEAD TO VOLUME DEPLETION: MAKING
CHALLENGING VENOUS ACCESS
ī IVFs: 1/2DNS since NMB
ī Blood in hand
ī Injection Cefazolin 30mg/kg i/v 1 hr before
procedure 12
13. VENOUS ACCESS
ī Route of access depends on:
ī Operator experience
ī Presence of cardiac devices and indwelling catheters
ī Prior h/o venous cannulation and associated
complications
ī FV access commonly used in children or if LHC
performed concurrently
ī Small studies demonstrated feasibility and
safety of RHC+LHC via ACV and radial artery
respectively
Yang CH, Guo GB, Yip HK. Bilateral cardiac catheterizations: the safety and feasibility of a superficial forearm venous and transradial arterial
approach. Int Heart J 2006;47:21â7.
Lo TS, Buch AN, Hall IR, et al. Percutaneous left and right heart catheterization in fully anticoagulated patients utilizing the radial artery and
forearm vein: a two-center experience. J Interv Cardiol 2006;19:258â63
Gilchrist IC, Kharabsheh S, Nickolaus MJ, et al. Radial approach to right heart catheterization: early experience with a promising technique.
13
14. VENOUS ACCESS CONTâĻ
ī USG guided vs landmark based:
īMeta-analysis available
īClear benefit of USG for IJV cannulation
īHigher success rate
īFewer complications
īFaster access
Hind Daniel, Calvert Neill, McWilliams Richard, et al. Ultrasonic locating devices for central venous cannulation: meta-analysis. BMJ
2003;327:361.
ī Data very limited: USG for FV and SCV
cannulation
14
15. VENOUS ACCESS CONTâĻ
ī Balloon flotation catheters (Swan- Ganz) :
Balloon at distal end, facilitate passage through
RH
ī Designed to be placed without fluoroscopy,
although screening helps (marked RH
dilatation/ severe TR)
15
16. VENOUS ACCESS CONTâĻ
ī Catheter inserted into RA and balloon inflated
ī Catheter then follows direction of blood flow
towards PAs
ī Advancing further should allow performer to
obtain PCWP
ī Important to avoid leaving balloon inflated for
longer than necessary : Risk of pulmonary
infarction/ rupture
16
17. CATHETERIZATION FROM FV
ī Commonly performed using multipurpose end
hole catheter using direct fluoroscopy
ī Requires greater manipulation than balloon
flotation catheters to navigate through RH:
Guide wire may be required to improve
steerability
ī MP catheters can be used to
cross directly into LA in patients
with PFO for direct pressure
17
18. PROCEDURE
ī Before starting: Confirm pressure transducers
are zeroed, leveled, appropriately calibrated
ī Establishment of âzeroâ value is the concept of
making hydrostatic measurements with fluid
filled systems relative to a reference value,
usually atmospheric pressure (760mm Hg),
then examining the change from that value
18
19. PROCEDURE
ī Transducer should be placed at appropriate
level
ī For every 1cm above LA the catheter is
referenced, the pressure measurement is
underestimated by 0.74mmHg and vice versa
19
21. THE CONCEPT OF PHLEBOSTATIC AXIS
ī Correct reference point
ī Midpoint b/w anterior
and posterior surfaces
of chest at 4th ICS
ī Essential that level of
stopcock of transducer
be at this level
ī All transducers must
be at this level
21
22. PRINCIPALS TO BE ADHERED TO DURING CATH
STUDY
ī Data to be obtained in a steady state
ī Essential to maintain decorum in a quiet and
calm environment
ī Appropriate sedation needed in case of agitated
child
ī Watch for over sedation: Respiratory
depression, consequently changes in sats
22
23. PRINCIPALS TO BE ADHERED TO DURING CATH
STUDY
ī Obtain entire data in<7 mins
ī Withdrawal pressures and saturations better
than ingoing
ī If sample canât be obtained from a site due to
ventricular premature complex, skip site until
rest of run completed
ī Complete hemodynamic data must be obtained
before angiograms
ī Obtain pressures and oxymetry samples as
close in time as possible
23
24. PRINCIPALS TO BE ADHERED TO DURING CATH
STUDY
ī Repeated measurements : More accurate
ī Record catheter course
ī An end hole catheter (eg: Swan Ganz) or one
with side holes close to its tip (eg. NIH) can be
used
ī Sat syringes not to be overheparinized, sample
gets diluted; just quote the inner lining of the
syringe
ī Remove air bubbles: PO2 rises
24
25. PRINCIPALS TO BE ADHERED TO DURING CATH
STUDY
ī Glass syringes: Gold standard
ī Plastic syringes: Porous, fall in PO2
ī Metabolism of WBCs: Tends to fall in PO2
ī Measure sats <5 mins (if delay: Transfer in ice
<30 mins)
25
26. USE DEDICATED OXYMETRY MACHINE
ī Should be in lab
ī Measures directly the o2 saturation using
spectrophotometry to correctly quantify oxy,
deoxy, carboxy and methHb and total Hb
ī Do not use ABG machines: O2 saturation
results derived from o2 dissociation curves,
using PO2 values: Which is affected by many
factors ( Adult or fetal Hb, temp, ph, CO2, 2,3-
DPG levels)
26
27. THE ACTUAL MEASUREMENTS FOR SHUNTS
âĸ Place catheter in PA (Swan Ganz) and pigtail in Ao
âĸ Measure PA and Ao pressures
âĸ Take o2 sat in PA+ Ao blood
âĸ Enter LV by retrograde crossing of Ao valve
âĸ Advance PA catheter to PCWP position
âĸ Measure simultaneously LV-PCWP pressures
27
28. THE ACTUAL MEASUREMENTS FOR SHUNTS
CONTâĻ
âĸ Pull back from PCWP to PA
âĸ Pull back from PA to RV for PS and record RV
pressure. Take RV sample for O2 sats
âĸ Record simultaneous LV-RV pressure
âĸ Pull back from RV to Rato screen for tricuspid
stenosis and record RA pressure. Take RA sample
âĸ Take SVC+IVC samples for O2 saturations
âĸ Pull back from LV to aorta for AS
28
29. NORMAL PRESSURE VALUES OF VARIOUS
HEART CHAMBERS
CHAMBER AVERAGE PRESSURE
RA 6/5/3
RV 25/4
PA 25/9/15
PCWP 9
LA 10/12/8
LV 130/8
Ao 130/70/85
29
30. DO MAKE A NOTE OF THESE
ī Mean RA pressure=RVEDP
ī RVSP=Peak PA pressure
ī PA diastolic pressure=Mean PCWP=Mean LA
pressure= LVEDP
ī LVSP=Ao pressure
ī Presence of gradients across these chambers
indicates obstruction to blood flow
30
31. RIGHT ATRIAL PRESSURES
ī A: Atrial systole, just
after P wave
ī C: RV contraction/ TV
closure
ī V: Filling of RA against
closed TV valve
ī X: Atrial relaxation
ī Y: Opening of TV in
early diastole
31
32. RV PRESSURE
ī A rapid upstroke
during isovolumetric
contraction
ī A plateau during
systolic ejection
ī A decline to near zero
during isovolumetric
relaxation
ī A slow rise to the end
diastolic pressure
during diastolic filling
32
33. PA PRESSURE
ī PA systolic pressure=
RVSP (<30mm Hg)
ī Mean pressure< 20mm
Hg
ī PA diastolic pressure
begins with dicrotic
notch caused by valve
closure, and the diastolic
pressure is typically no
more than 2-3 mm Hg
higher than the wedge
pressure
33
34. PCWP
ī Is usually a good
reflection of LA and
LVEDP because of
absence of valves in
pulmonary circulation
ī It has the characteristic
a and v wave
appearance of an atrial
tracing
34
35. SATURATIONS
Site Average Range
SVC 74% 67-83%
IVC 78% 65-87%
RA 75% 65-87%
RV 75% 67-84%
PA 75% 67-84%
LA 95% 92-98%
LV 95% 92-98%
FA 95% 92-98%
35
37. WHEN IS IT UTILISED?
ī When the is discrepancy b/w physical and
non-invasive findings
ī At the time of device closure
ī Assessment of shunt operability in patients
with severe PAH with borderline findings
37
38. SHUNT DETECTION
ī Oximetric run used
ī Past: Indicator dye (Indocyanine green) used
īDetected very small ltī rt shunt missed by
oxymetry
īNo longer used
ī Presence of unexplained arterial desaturation
(FA SaO2<95%) or unexpectedly high O2
content in PA (SaO2>80%): Raises suspicion of
rtī lt or a ltī rt shunt respectively. Follow this
by a complete oximetry run 38
39. OXIMETRY RUN
ī Full oximetry run
involves taking serial
samples at following
locations:
ī Lt+ rt. PA
ī MPA
ī RVOT
ī RV mid
ī RV tricuspid valve or
apex
ī RA low or near TV
ī RA high
ī SVC low (near RA
junction)
ī SVC high (near
innominate vein junction)
ī IVC high ( just at/ below
diaphragm)
ī IVC low L4-5
ī LV
ī Ao (diatal to ductus
insertion)
39
40. DETECTION OF LEFT TO RIGHT SHUNT BY
OXIMETRY
Antman et al, AJC 80; Barrat et al, JLCM 57, Freed et al, BHJ 79
40
41. CAUSES OF STEP UP AT ATRIAL LEVEL
ASD
PAPVC
VSD with TR
RSOV ī RA
LV ī RA shunt
Cor AV Fistula ī RA
41
42. CAUSES OF STEP UP AT VENTRICULAR LEVEL
VSD
RSOV ī RV
Low ASD
Cor AV Fistula ī RA
PDA with PR
AVSD
42
43. CAUSES OF STEP UP AT GREAT VESSEL LEVEL
Patent Ductus Arteriosus
Aorto-pulmonary Window
Outlet VSD
Coronary origin from pulmonary artery
43
44. LIMITATIONS
ī Steady state may not be present: Patient
agitation/ Arrhythmias
ī Lacks sensitivity. Small shunts may be missed
ī In conditions of high level of systemic blood
flow, mixed venous o2 sats tends to be higher
than normal and interchamber variablility would
be reduced equalization of arterial and venous
blood 44
45. UNDERSTANDING THE FICKâS PRINCIPAL
Total uptake/release of a substance by an
organ is the product of the bld flow to the organ
and the AV concentration difference of the
substance
45
46. PULMONARY BLOOD FLOW
ī Using lung as an organ and O2 as substance:
Bld flow to lung will be:
ī Qp (L/min) =O2 consumption(VO2)/ AV O2
difference
=VO2/ PV O2 content-PA O2 content
46
47. PBF
If PV canât be entered
See systemic arterial O2 content
âĨ95% <95
Use this value Determine if rtī lt shunt
+nt ânt
Use 98% value Use observed systemic
arterial saturation value 47
48. SYSTEMIC BLOOD FLOW
ī Using body as an organ and O2 as substance:
Bld flow to body will be:
ī Qs= o2 consumption(VO2)/ SA02-MVO2
ī Note: In presence of shunt lesions, the MVO2 is
to be measured in the chamber immediately
proximal to the shunt
48
49. CALCULATION OF QS IN PRESENCE OF LT->RT
SHUNT
49
Grossman & Baimâs, 8th edition (FLAMMâS FORMULA)
50. SHUNT QUANTIFICATION
ī Absolute terms (L/min)=Qp-Qs
ī Relative terms (ratio)=Qp/Qs
ī Ratio advantageous as it takes out unreliable
variables like VO2
ī Qp/Qs=(SAO2-MVO2)/ (PVO2-PAO2)
50
51. QP/QS
ī 1: No shunt
ī <1: Rtī lt shunt
ī 1-1.5: Small ltī rt shunt (in absence of PAH;
would not need closure)
ī 1.5-2: Intermediate ltī rt shunts (may be
closed if risk of closure low)
ī >2: Large ltī rt shunt (Needs closure)
51
52. CALCULATION OF BIDIRECTIONAL SHUNT
ī Effective bld flow: Flow that would exist in
absence of any ltâ>rt or rtī lt shunt
ī Qeff= O2 consumption/ (PVO2-MVO2)
ī Ltī rt: Qp-Qeff
ī Rtī lt: Qs-Qeff
52
53. SHUNT OPERABILITY
ī Large shunts: High PAH due to increased flow
ī Anatomic changes takes place in pul.
vasculature
ī Reversible initially, later ir-reversible
ī As PVRI increases> 6-8 Wood U: Poor
operative outcome
ī In these cases: If PAH irreversible; Sx tends to
transform these from Eisenmengerâs syndrome
to one analogous to idiopathic PAH
53
54. SHUNT OPERABILITY CONTâĻ
ī Compared to idiopathic PAH; pts. With ES have
much better prognosis with 40% expected to
survive till 25 yoa
ī Assessment of operability is not an â all or
noneâ phenomenon
ī Clinical and non invasive parameters too are
considered
54
55. CLINICAL & NON INVASIVE FINDINGS TO ASSESS
SHUNT OPERABILITY
55
Vijaylaxmi: Cardiac Catheterization From Pediatric to Geneatric: 1st edition
56. HEMODYNAMIC ASSESSMENT OF SHUNT
OPERABILITY
ī Favorable outcomes:
īBaseline Qp/Qs >1.5-2
īPVRI <6Wood U
īPVR:SVR <0.3 without vasoreactive test
īAge <1 year (Most imp.)
56
57. TECHNIQUES TO ASSESS OPERABILITY
ī Lung biopsy
ī Exposure to vasodilator
ī Temporary balloon occlusion of defect
57
58. 01. LUNG BIOPSY
ī Gold standard
ī Heath Edward classification Grade 4-6:
Irreversible
ī Invasive
ī Associated with morbidity
ī Not available at all centers
ī Some studies have questioned reliability
58
60. 02. EXPOSURE TO VASODILATOR
ī 100% O2
ī NO (+/- O2)
ī Tolazoline
ī Adenosine
ī Epoprostenol
ī Used to assess pulmonary reactivity in cath
labs
60
61. PROCEDURE
ī Pt. adequately sedated
ī Obtain baseline rt/lt heart studies (PVRI,SVRI,
Qp, Qs)
ī 100% o2 X 10 mins
ī Repeat rt/lt heart studies (recalculate Qp, Qs,
PVRI, SVRI)
ī If NO used: 20-80ppm by NO ventilator
61
62. TIPS FOR CALCULATION
ī O2 consumption remains constant
ī Post O2 inhalation: Dissolved O2 must be taken
into account in calculating O2 content
ī Failure to take into consideration the dissolved
O2 may make an inoperable case appear
operable
ī In pts with a positive response , there is a fall in
the diastolic and mean PA pressures without a
fall/rise in Ao pressure/ CO
62
63. PRESENCE OF ALL OF THESE INDICATES
FAVOURABLE OUTCOME FOLLOWING SURGERY
ī Decrease of 20% in PVRI
ī Decrease of 20% in PVR: SVR ratio
ī Final PVRI <6Woods U/m2
ī Final ratio of PVR: SVR <0.3
63
64. 03. TEMPORARY BALLOON OCCLUSION
ī Occlusion abolishes ltī rt shunt
ī Operable pts: Drop in PA pressure
ī Inoperable pts: No drop in PA pressure; actual
rise in PA pressure with/without a fall in Ao
pressure
ī Best studied in PDAs and sometimes in ASDs
ī Technically difficult in VSDs
64
65. PDA BALLOON OCCLUSION
ī 10 mins occlusion
ī A 25% fall in PA pressures or 50% fall in ratio
b/w pulmonary and Ao diastolic pressures
ī A fall in PA pressure with a > 20 mm Hg
systolic, diastolic and mean pressure difference
b/w PA and FA during balloon occlusion
65
66. ASD BALLOON OCCLUSION
ī 15 mins
ī +ve response: Mean reduction in pulmonary
pressure of âĨ25% after balloon occlusion
compared to basal levels, without a fall in
systemic pressure or an increase in VEDP
66
70. A. FICK METHOD OF CO ESTIMATION
ī Gold standard
ī Fickâs principal
ī In the absence of shunts:
Qp=Qs=CO
ī Also useful in patients with TR where
thermodilution method is unreliable
ī 2 main variables:
īO2 consumption (VO2)
īAVO2 70
71. 01. O2 CONSUMPTION (VO2)
ī Earlier methods: Rarely used
ī Douglas bag/ polarography method/ paramagnetic
method
ī Cumbersome/ specialized equipments/ experienced
personnel
ī Only means of getting accurate VO2
ī Children: La Farge- Miettinen tables
71
72. LA FARGE- MIETTINEN TABLES: BOYS
72Vijaylaxmi: Cardiac Catheterization From Pediatric to Geneatric: 1st edition
73. LA FARGE- MIETTINEN TABLES: GIRLS
73Vijaylaxmi: Cardiac Catheterization From Pediatric to Geneatric: 1st edition
74. 02. AV O2 DIFFERENCE
ī O2 content
= O2 bound to Hb+ Dissolved O2
= 1.36mlx Hbx saturation+ 0.003mlxPaO2
ī In pts on RA: Content of dissolved O2 low:
Hence ignored (= 1.36x Hb(g/L)X 10X (AO2-
MVO2)
ī If breathing with FiO2 >50%: Take dissolved O2
too (Imp when shunt operability in severe PAH
cases is assessed) 74
75. BEFORE STARTING THE CASE, DO HAVE THESE
HANDY
ī Hb level
ī Ht +Wt for BSA calculation
ī HR, age, sex: For VO2
75
76. LIMITATIONS OF THE FICK PRINCIPAL
ī Use of assumed VO2 value (Errors of 10-25%
can creep in)
ī Inability to obtain steady state under certain
circumstances (samples to be obtained
simultaneously)
ī Do not use this method in: Significant MR, AR
76
77. B. THERMODILUTION METHOD OF CO
ESTIMATION
ī Values correlate well to Fick method
ī Involves determining the extent and rate of
thermal changes in blood stream following
injection of fixed vol of cold NS
ī Temperature time curve obtained: Area gives
CO
77
78. METHOD
ī Distal tip of Swan Ganz catheter placed in PA,
proximal port in RA
ī 10 ml NS bolus injected rapidly in proximal port at
a constant rate
ī Resultant change in temperature in liquid
measured by thermistor mounted at the distal end
of catheter
ī Result displayed on computer
ī This is repeated 3 times
ī 3 recordings should be within 15-20% of each
other, otherwise repeat the procedure 78
79. LIMITATIONS OF THERMODILUTION METHOD
ī Do not use in:
īSevere TR
īLow CO states (overestimates CO)
īIntracardiac shunts
īMarked respiratory variation
īCardiac arrhythmias
79
80. C. ANGIOGRAPHIC METHOD OF CO ESTIMATION
ī CO=SV X HR
ī SV= EDV- ESV
ī By tracing LV ED and ES images of a high
quality ventriculogram, EDV and ESV can be
calculated
ī There are inherent inaccuracies of calibrating
angiographic volumes: Rarely used clinically
ī Only use: Calculation of stenotic valve areas in
pts with significant AR or MR
80
82. RESISTANCE MEASUREMENT
ī Ohmâs law: R=V/I
ī Resistance= Î Pressure/ Flow
ī SVR= Mean Ao Pre â Mean RA pre/ Qs
īWood units(mm Hg/L/min)
īX 80: dynes/sec/cm-5
ī Normal SVR: 8-20 Wood U (700-1,66
dynes/sec/cm-5)
82
83. RESISTANCE MEASUREMENT CONTâĻ
ī PVR= Mean PA pre- Mean LA (or PCWP) pre/
Qp
ī Normal PVR: 20-130dynes/sec/cm-5(.25-1.6W
U)
ī PVRI = Mean PA- Mean PCWP/ CI
= Mean PA- Mean PCWP/Qp/BSA
= (Mean PA- Mean PCWP/ Qp) x BSA
= PVR X BSA
83
86. CONSTRICTIVE PERICARDITIS
ī Hallmark: Diastolic pressure equalization in all
heart chambers due to global inhibition of
diastolic filling from a fibrous, non-compliant
pericardial sac
ī Square root sign: Dip and plateau pattern in RV
pressure waveform
ī Dip: Unimpaired early diastolic filling of ventricles,
coupled with high LA+RA pressures at the moment
the mitral and tricuspid valves open
ī Plateau: Ventricles then fill rapidly and suddenly
meet the constraints of a rigid pericardium:
Pressure in ventricles reaching a plateau 86
87. SQUARE ROOT SIGN OF CP
87
Callan P, Clark AL.Heart2016;102:1â11. doi:10.1136/heartjnl-2015-307786
88. CP CONTâĻ
ī Treatment with high dose
diuretics prior to cath: May
result in low filling pressure,
lead to incorrect exclusion
of diagnosis of constriction
ī Low filling pressures due to
hypervolemia in the
absence of constriction:
May lead to an apparent
pressure equalization and a
FP result
ī A fluid challenge can help in
improving diagnostic power
in both situations 88
Predictive accuracy of individual: 70-85%
PPV if all 3 fulfilled> 90%
Vaitkus P. Kussmaul W. Constrictive pericarditis versus restrictive
cardiomyopathy: a reappraisal and update of diagnostic criteria.
Am Heart J 1991;122:1431 â41.
89. RESTRICTIVE CARDIOMYOPATHY
ī Pressure changes can resemble those of CP,
although LV diastolic pressure is usually
appreciably higher than the right
ī Diastolic pressure may be coincidentally nearly
identical in both ventricles
ī Dip and plateau pattern: Often seen, but with
the diastolic constrain in due to impaired
ventricular relaxation rather than pericardial
constrain 89
91. 01. ERRORS IN PRESSURE RECORDING
ī Errors at zero level, balancing, calibration of
transducers
ī Clots or kinks in the system
ī Loose connections/ defective transducers
ī Use of multi hole catheter for withdrawal gradients
ī Artifacts: Catheter whip artifact, end pressure
artifact, catheter impact artifact, wedging of
catheter, hybrid tracings
ī Systolic pressure amplification in periphery
ī Use of computer derived mean values in patients
with marked respiratory variation 91
92. 02. ERRORS IN SAMPLING
ī Obtaining samples in different physiologic
states ( arrhythmias, acidosis,
hypoventilation)
ī Partial wedging of catheter (PA)
ī Non representative sampling (PVs)
92
93. 03. ERRORS IN OXIMETRY
ī Diluted samples (saline/ heparin)
ī Air bubble in syringe
ī Delay in sample sending
ī Using ABG samples to estimate O2 sats
ī Using non standardized equipment
93
94. 04. ERRORS IN CALCULATION
ī Assumed VO2
ī Assumed PV saturation
ī Failure to account for dissolved O2 during
O2 study
ī Flows corrected for BSA by dividing instead
of multiplying
ī Errors in identifying the mixing chamber
correctly and using O2 sats from wrong
chamber
94
96. ANGIOGRAMS
ī Should be performed after all hemodynamic
and oximetry data have been obtained
ī In pts with elevated LVEDP/ PCWP (>25
mmHg), avoid angiograms or perform only it
has been reduced to safe levels with NTG/ lasix
96
97. PRIOR TO PERFORMING ANGIOGRAMS, ALWAYS
DO:
ī Confirm the catheter type (Berman and not
Swan)
ī Ensure the catheter is not entrapped and no
air bubble
ī Perform a test injection to confirm that
catheter has not migrated
ī Confirm the contrast volume, flow rates and
injection pressures
97
98. COMMONLY USED RADIOLOGICAL VIEWS
98Vijaylaxmi: Cardiac Catheterization From Pediatric to Geneatric: 1st edition