CARDIAC CATHETERISATION

CARDIAC CATHETERISATION: PRINCIPALS & PRACTICES

1. Murtaza kamal Murtaza.vmmc@ gmail .com 20/09/2018 PRINCIPLES AND PRACTICES OF CARDIAC CATHETERISATION 1

2. OBJECTIVES… Overview of history and development How to perform a study tailored to answer specific clinical question Gain better understanding of role of as a diagnostic tool in specific situations 2

3. CLAUDE BERNARD 1844: France 1 st RHC on horse Inserted glass tubes via jugular vein and carotid artery Measured temperature in both ventricles Later measured intracardiac pressures too 3 Nossaman BD et al. H/o RHC: 100 years of experimentation and methodology development. Cardiol Rev 2010;18:94-101.

4. WERNER FORSSMANN 1929; Germany Self catheterization using urethral catheter Used lt. anticubital vein  RV; (X-RAY) Against medical ethics 4 Meyer JA. W Forssmann and catheterisation of the heart, 1929. Ann Thorac Surg 1990;49:497-9

5. Finally got recognized… 5 The Nobel Foundation: 1956

6. Introduction Advent of non-invasive modalities (ECHO, MRI): Cardiac catheterization reduced Gold standard: For assessment of cardiac hemodynamics Resolves discrepancy b/w c/fs+ non-invasive measurements 6

7. Introduction Cont … Through review of clinical history, physical exam, ECG, CXR, ECHO, MRI(+/-) before patient enters cath lab Why is study performed? If results are not going to alter course of management: Best not to perform Have clear idea as what is the data one wishes to seek Wild goose chase: More questions than answers 7

8. Conduct of catheterization study Adherence to standard protocols Due attention to pressure recordings and saturation assessments Flexibility: Each case is different 8

9. PATIENT PREPARATION Parents informed of indication and risks of procedure Retrospective and prospective data: 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 CONT… MC complications: Access site hematoma Vagal reaction Pneumothorax Arrhythmias Quote individual/ departmental complications 10

11. Patient preparation Rule out anemia, infections, thrombocytopenia Electrolyte/ metabolic disturbances Dehydration Digoxin toxicity 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. protocol Cath profile and PAC clearance before admission (1 day prior) NBM: 4 hours before Caution: OVERZELOUS FASTING PROTOCOLS MAY LEAD TO VOLUME DEPLETION: MAKING CHALLENGING VENOUS ACCESS IVFs: 1/2DNS since NMB Blood in hand Injection Cefazolin 30mg/kg i/v 1 hr before procedure 12

13. VENOUS ACCESS Route of access depends on: Operator experience Presence of cardiac devices and indwelling catheters Prior h/o venous cannulation and associated complications FV access commonly used in children or if LHC performed concurrently Small studies demonstrated feasibility and safety of RHC+LHC via ACV+ 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;47:21–7. 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;19:258–63 Gilchrist IC, Kharabsheh S, Nickolaus MJ, et al. Radial approach to right heart catheterization: early experience with a promising technique. Catheter Cardiovasc Interv 2002;55:20–2 Gilchrist IC, Moyer CD, Gascho JA. Transradial right and left heart catheterizations: a comparison to traditional femoral approach. Catheter Cardiovasc Interv 2006;67:585–8 13

14. VENOUS ACCESS CONT… USG guided vs landmark based: Meta-analysis available Clear benefit of USG for IJV cannulation Higher success rate Fewer complications Faster access Hind Daniel, Calvert Neill, McWilliams Richard, et al. Ultrasonic locating devices for central venous cannulation : meta-analysis. BMJ 2003;327:361. Data very limited: USG for FV and SCV cannulation 14

15. VENOUS ACCESS CONT… Balloon flotation catheters (Swan- Ganz ) : Balloon at distal end, facilitate passage through RH Designed to be placed without fluoroscopy, although screening helps (marked RH dilatation/ severe TR) 15

16. VENOUS ACCESS CONT… Catheter inserted into RA and balloon inflated Catheter follows direction of blood flow towards PAs Advancing further should allow performer to obtain PCWP Important to avoid leaving balloon inflated for longer than necessary : Risk of pulmonary infarction/ rupture 16

17. Catheterization from FV Commonly performed using multipurpose end hole catheter using direct fluoroscopy Requires greater manipulation than balloon flotation catheters to navigate through RH: Guide wire may be required to improve steerability MP catheters can be used to cross directly into LA in patients with PFO for direct pressure recordings 17

18. PROCEDURE Before starting: Confirm pressure transducers are zeroed, leveled, appropriately calibrated Establishment of “zero” value: Concept of making hydrostatic measurements with fluid filled systems relative to a reference value, usually atmospheric pressure (760mm Hg), then examining change from that value 18

19. PROCEDURE Transducer should be placed at appropriate level For every 1cm above/ below LA the catheter is referenced, the pressure measurement is underestimated/ overestimated by?? 0.74mmHg 19

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21. THE CONCEPT OF PHLEBOSTATIC AXIS Correct reference point Midpoint b/w anterior and posterior surfaces of chest at 4 th ICS Essential that level of stopcock of transducer be at this level All transducers must be at this level 21

22. PRINCIPALS TO BE ADHERED TO DURING CATH STUDY Data to be obtained in a steady state Essential to maintain decorum in a quiet and calm environment Appropriate sedation needed in case of agitated child Watch for over sedation: Respiratory depression, consequently changes in sats 22

23. PRINCIPALS TO BE ADHERED TO DURING CATH STUDY Obtain entire data in………..?? Withdrawal pressures and saturations better than ingoing If sample can’t be obtained from a site due to ventricular premature complex: Skip site until rest of run completed Complete hemodynamic data must be obtained before angiograms Obtain pressures and oxymetry samples as close in time as possible 23

24. PRINCIPALS TO BE ADHERED TO DURING CATH STUDY Repeated measurements : More accurate Record catheter course Sat syringes not to be overheparinized , sample gets diluted; just quote inner lining of syringe Remove air bubbles: PO2 rises 24

25. PRINCIPALS TO BE ADHERED TO DURING CATH STUDY Glass syringes: Gold standard Plastic syringes: Porous, fall in PO2 Metabolism of WBCs: Tends to fall in PO2 Measure sats <5 mins (if delay: Transfer in ice <30 mins ) 25

26. USE DEDICATED OXYMETRY MACHINE Should be in lab Measures directly o2 saturation using spectrophotometry to correctly quantify oxy, deoxy, carboxy and methHb and total Hb Do not use ABG machines: WHY??? O2 saturation results derived from o2 dissociation curves, using PO2 values: Affected by many factors ( Adult or fetal Hb, temp, ph , CO2, 2,3-DPG levels) 26

27. THE ACTUAL MEASUREMENTS FOR SHUNTS 27

28. THE ACTUAL MEASUREMENTS FOR SHUNTS CONT… 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 Mean RA pressure=RVEDP RVSP=Peak PA pressure PA diastolic pressure=Mean PCWP=Mean LA pressure= LVEDP LVSP= Ao pressure Presence of gradients across these chambers indicates obstruction to blood flow 30

31. RIGHT ATRIAL PRESSURES A: Atrial systole, just after P wave C: RV contraction/ TV closure V: Filling of RA against closed TV valve X: Atrial relaxation Y: Opening of TV in early diastole 31

32. RV Pressure A rapid upstroke during isovolumetric contraction A plateau during systolic ejection A decline to near zero during isovolumetric relaxation A slow rise to the end diastolic pressure during diastolic filling 32

33. PA PRESSURE PA systolic pressure= RVSP (<30mm Hg) Mean pressure< 20mm Hg 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 Is usually a good reflection of LA and LVEDP because of absence of valves in pulmonary circulation 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

36. Saturations Coronary sinus?? 36

37. 37 SHUNT DETECTION & QUANTIFICATION

38. WHEN IS IT UTILISED? Discrepancy b/w physical and non-invasive findings Time of device closure Assessment of shunt operability in patients with severe PAH with borderline findings 38

39. SHUNT DETECTION Oximetric run used Past: Indicator dye ( Indocyanine green) used Detected very small lt  rt shunt missed by oxymetry No longer used Presence of unexplained arterial desaturation (FA SaO2<95%) or unexpectedly high O2 content in PA (SaO2>80%): Raises suspicion of rt lt or a lt  rt shunt respectively Follow this by a complete oximetry run 39

40. Oximetry run Full oximetry run involves taking serial samples at following locations: Lt+ rt. PA MPA RVOT RV mid RV tricuspid valve or apex RA low or near TV RA mid RA high SVC low (near RA junction) SVC high (near innominate vein junction) IVC high ( just at/ below diaphragm) IVC low L4-5 LV Ao ( diatal to ductus insertion) 40

41. DETECTION OF LEFT TO RIGHT SHUNT BY OXIMETRY 41 Antman et al, AJC 80; Barrat et al, JLCM 57, Freed et al, BHJ 79

42. CAUSES OF STEP UP AT ATRIAL LEVEL?? ASD PAPVC VSD with TR RSOV  RA LV  RA shunt Cor AV Fistula  RA 42

43. CAUSES OF STEP UP AT VENTRICULAR LEVEL?? VSD RSOV  RV Low ASD Cor AV Fistula  RA PDA with PR AVSD 43

44. CAUSES OF STEP UP AT GREAT VESSEL LEVEL?? Patent Ductus Arteriosus Aorto -pulmonary Window Outlet VSD Coronary origin from pulmonary artery 44

45. LIMITATIONS Steady state may not be present: Patient agitation/ Arrhythmias Lacks sensitivity: Small shunts may be missed 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 45

46. UNDERSTANDING THE FICK’S 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 46

47. PULMONARY BLOOD FLOW Lung as an organ and O2 as substance: Bld flow to lung will be: Qp (L/min) = O2 consumption(VO2) / AV O2 difference =VO2/ PV O2 content-PA O2 content 47

48. PBF If PV can’t be entered See systemic arterial O2 content ≥95% <95 Use this value Determine if rt  lt shunt + nt – nt Use 98% value Use observed systemic arterial saturation value 48

49. SYSTEMIC BLOOD FLOW Using body as an organ and O2 as substance: Bld flow to body will be: Qs= o2 consumption(VO2)/ SA02-MVO2 In presence of shunt lesions, MVO2 is to be measured in chamber immediately proximal to shunt 49

50. Calculation of QS in presence of lt -> rt shunt 50 Grossman & Baim’s , 8 th edition (FLAMM’S FORMULA)

51. SHUNT QUANTIFICATION Absolute terms (L/min)= Qp -Qs Relative terms (ratio)= Qp /Qs Ratio advantageous as it takes out unreliable variables like VO2 Qp /Qs=(SAO2-MVO2)/ (PVO2-PAO2) 51

52. QP/QS 1: No shunt <1: Rt lt shunt 1-1.5: Small lt  rt shunt (in absence of PAH; would not need closure) 1.5-2: Intermediate lt  rt shunts (may be closed if risk of closure low) >2: Large lt  rt shunt (Needs closure) 52

53. CALCULATION OF BIDIRECTIONAL SHUNT Effective bld flow: Flow that would exist in absence of any lt —> rt or rt  lt shunt Qeff = O2 consumption/ (PVO2-MVO2) Lt rt : Qp-Qeff Rt  lt : Qs- Qeff 53

54. SHUNT OPERABILITY Large shunts: High PAH due to increased flow Anatomic changes takes place in pul . vasculature Reversible initially, later ir -reversible As PVRI increases> 6-8 Wood U: Poor operative outcome In these cases: If PAH irreversible; Sx tends to transform these from Eisenmenger’s syndrome to one analogous to idiopathic PAH 54

55. SHUNT OPERABILITY CONT… Compared to idiopathic PAH; pts. with ES have much better prognosis with 40% expected to survive till 25 yoa Assessment of operability is not an “ all or none” phenomenon Clinical and non invasive parameters too are considered 55

56. CLINICAL & NON INVASIVE FINDINGS TO ASSESS SHUNT OPERABILITY 56 Vijaylaxmi : Cardiac Catheterization From Pediatric to Geneatric : 1 st edition

57. HEMODYNAMIC ASSESSMENT OF SHUNT OPERABILITY Favorable outcomes: Baseline Qp /Qs >1.5-2 PVRI <6Wood U PVR:SVR <0.3 without vasoreactive test Age <1 year (Most imp.) 57

58. TECHNIQUES TO ASSESS OPERABILITY Lung biopsy Exposure to vasodilator Temporary balloon occlusion of defect 58

59. 01. LUNG BIOPSY Gold standard Heath Edward classification Grade 4-6: Irreversible Invasive Associated with morbidity Not available at all centers Some studies have questioned reliability 59

60. HEATH-EDWARDS CLASSIFICATION 60

61. 02. EXPOSURE TO VASODILATOR 100% O2 NO (+/- O2) Tolazoline Adenosine Epoprostenol Used to assess pulmonary reactivity in cath labs 61

62. PROCEDURE Pt. adequately sedated Obtain baseline rt / lt heart studies (PVRI,SVRI, Qp , Qs) 100% o2 X 10 mins Repeat rt / lt heart studies (recalculate Qp , Qs, PVRI, SVRI) If NO used: 20-80ppm by NO ventilator 62

63. TIPS FOR CALCULATION O2 consumption remains constant Post O2 inhalation: Dissolved O2 must be taken into account in calculating O2 content Failure to take into consideration the dissolved O2 may make an inoperable case appear operable 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 63

64. PRESENCE OF ALL OF THESE INDICATES FAVOURABLE OUTCOME FOLLOWING SURGERY Decrease of 20% in PVRI Decrease of 20% in PVR: SVR ratio Final PVRI <6Woods U/m2 Final ratio of PVR: SVR <0.3 64

65. 03. TEMPORARY BALLOON OCCLUSION Occlusion abolishes lt  rt shunt Operable pts : Drop in PA pressure Inoperable pts : No drop in PA pressure; actual rise in PA pressure with/without a fall in Ao pressure Best studied in PDAs and sometimes in ASDs Technically difficult in VSDs 65

66. PDA Balloon occlusion 10 mins occlusion A 25% fall in PA pressures or 50% fall in ratio b/w pulmonary and Ao diastolic pressures A fall in PA pressure with a > 20 mm Hg systolic, diastolic and mean pressure difference b/w PA and FA during balloon occlusion 66

67. ASD BALLOON OCCLUSION 15 mins + ve response: Mean reduction in pulmonary pressure of ≥25% after balloon occlusion compared to basal levels, without a fall in systemic pressure or an increase in VEDP 67

68. 68 MEASUREMENT OF CARDIAC OUTPUT

69. JUST A GLANCE AT THE FORMULAE 69 Callan P, Clark AL. Heart 2016;102:1–11. doi:10.1136/heartjnl-2015-307786

70. CARDIAC OUTPUT Fick method Thermo dilution method Angiographic method 70

71. A. FICK METHOD of co estimation Gold standard Fick’s principal In the absence of shunts: Qp =Qs=CO Also useful in patients with TR where thermodilution method is unreliable 2 main variables: O2 consumption (VO2) AVO2 71

72. 01. O2 CONSUMPTION (VO2) Earlier methods: Rarely used Douglas bag/ polarography method/ paramagnetic method Cumbersome/ specialized equipments / experienced personnel Only means of getting accurate VO2 Children: La Farge - Miettinen tables 72

73. La Farge - Miettinen tables: BOYS 73 Vijaylaxmi : Cardiac Catheterization From Pediatric to Geneatric : 1 st edition

74. La Farge - Miettinen tables: GIRLS 74 Vijaylaxmi : Cardiac Catheterization From Pediatric to Geneatric : 1 st edition

75. 02. AV O2 difference O2 content = O2 bound to Hb + Dissolved O2 = 1.36mlx Hbx saturation+ 0.003mlxPaO2 In pts on RA: Content of dissolved O2 low: Hence ignored (= 1.36x Hb (g/L)X 10X (AO2-MVO2) If breathing with FiO2 >50%: Take dissolved O2 too (Imp when shunt operability in severe PAH cases is assessed) 75

76. BEFORE STARTING THE CASE, do have these handy Hb level Ht + Wt for BSA calculation HR, age, sex: For VO2 76

77. LIMITATIONS OF THE FICK PRINCIPAL Use of assumed VO2 value (Errors of 10-25% can creep in) Inability to obtain steady state under certain circumstances (samples to be obtained simultaneously) Do not use this method in: Significant MR, AR 77

78. B. THERMODILUTION METHOD of co estimation Values correlate well to Fick method Involves determining the extent and rate of thermal changes in blood stream following injection of fixed vol of cold NS Temperature time curve obtained: Area gives CO 78

79. METHOD Distal tip of Swan Ganz catheter placed in PA, proximal port in RA 10 ml NS bolus injected rapidly in proximal port at a constant rate Resultant change in temperature in liquid measured by thermistor mounted at the distal end of catheter Result displayed on computer Repeated 3 times 3 recordings should be within 15-20% of each other, otherwise repeat procedure Result displayed is CO 79

80. LIMITATIONS OF THERMODILUTION METHOD Do not use in: Severe TR Low CO states (overestimates CO) Intracardiac shunts Marked respiratory variation Cardiac arrhythmias 80

81. c. Angiographic method of co estimation CO=SV X HR SV= EDV- ESV By tracing LV ED and ES images of a high quality ventriculogram , EDV and ESV can be calculated Inherent inaccuracies of calibrating angiographic volumes: Rarely used clinically Only use: Calculation of stenotic valve areas in pts with significant AR or MR 81

82. 82 MEASUREMENT OF RESISTANCE

83. Resistance measurement Ohm’s law?? R=V/I Resistance= Δ Pressure/ Flow SVR= Mean Ao Pre – Mean RA pre/ Qs Wood units(mm Hg/L/min) X 80: dynes/sec/cm-5 Normal SVR: 8-20 Wood U (700-1,66 dynes/sec/cm-5) 83

84. Resistance measurement cont … PVR= Mean PA pre- Mean LA (or PCWP) pre/ Qp Normal PVR: 20-130dynes/sec/cm-5(.25-1.6W U) PVRI = Mean PA- Mean PCWP/ CI = Mean PA- Mean PCWP/ Qp /BSA = (Mean PA- Mean PCWP/ Qp ) x BSA = PVR X BSA 84

85. Resistance measurement cont … 85

86. 86 ANGIOGRAMS

87. Angiograms Should be performed after all hemodynamic and oximetry data have been obtained In pts with elevated LVEDP/ PCWP (>25 mmHg), avoid angiograms or perform only it has been reduced to safe levels with NTG/ lasix 87

88. PRIOR TO PERFORMING ANGIOGRAMS, ALWAYS DO: Confirm catheter type Ensure catheter is not entrapped and no air bubble Perform a test injection to confirm that catheter has not migrated Confirm contrast volume, flow rates and injection pressures 88

89. COMMONLY USED RADIOLOGICAL VIEWS 89 Vijaylaxmi : Cardiac Catheterization From Pediatric to Geneatric : 1 st edition

90. 90 ERRORS AT VARIOUS LEVELS

91. 01. ERRORS IN PRESSURE RECORDING Errors at zero level, balancing, calibration of transducers Clots or kinks in system Loose connections/ defective transducers Use of multi hole catheter for withdrawal gradients Systolic pressure amplification in periphery Use of computer derived mean values in patients with marked respiratory variation 91

92. 02. ERRORS IN SAMPLING Obtaining samples in different physiologic states ( arrhythmias, acidosis, hypoventilation) Partial wedging of catheter (PA) Non representative sampling (PVs) 92

93. 03. ERRORS IN OXIMETRY Diluted samples (saline/ heparin) Air bubble in syringe Delay in sample sending Using ABG samples to estimate O2 sats Using non standardized equipment 93

94. 04. ERRORS IN CALCULATION Assumed VO2 Assumed PV saturation Failure to account for dissolved O2 during O2 study Flows corrected for BSA by dividing instead of multiplying Errors in identifying the mixing chamber correctly and using O2 sats from wrong chamber 94

95. 95 COMPLICATIONS

96. COMPLICATIONS Access site complications: Access site hematomas Pseudoaneurysms AV fistulas IJV access: Hemo / pneumothorax Acute/ chronic limb ischemia: Loss of pulses secondary to thrombosis Femoral vein thrombosis 96

97. COMPLICATIONS CONT… Arrtythmias : Ventricular/ Supraventricular- Transient Embolism: Espec in rt  lt shunts Air/ blood clots Lead to stroke/ MI/ pulmonary or peripheral embolism Appropriate anticoagulation and diligence during flushing essential Avoid entry into LV in pts with LV clot/ Ao valve endocardotis 97

98. COMPLICATIONS CONT… Infections Bacterial endocarditis Cardiac perforation Tamponade Contrast reaction Precipitation of pulmonary edema Retained equipment ARF Rarely death 98

99. SO, TAKE HOME MESSAGE IS… Catheterization is like a puzzle Everything must fit with everything else 99