Approach to TOF physiology

Clinical approach to TOF physiology - cyanotic congenital heart disease with decreased pulmonary blood flow

1. DIFFERENTIAL DIAGNOSIS of TOF PHYSIOLOGY Satyam Rajvanshi

2. Cyanotic chd CLASSIFICATION

3. Cyanotic CHD CLASSIFICATION Anatomico -pathological Physiological

4. Cyanotic CHD with Increased PBF (5 Ts and 2 Ss) TAPVC – Single Ventricle TGA – Single (Common) Taussig -Bing Atrium Tricuspid Atresia Truncus Arteriosus

5. Cyanotic CHD with Increased PBF (5 Ts and 2 Ss)

6. Cyanotic CHD with Decreased PBF

7. Cyanotic CHD with Decreased PBF

8. Cyanotic CHD with Near Normal PBF Pulmonary AV Fistula Unroofed coronary sinus into LA Anomalous drainage of vena cava to LA

9. CCHD Physiological classification TOF Physiology Transposition Physiology Admixture Physiology Eisenmenger Physiology Duct-dependent Physiology For PBF – Pulmonary atresia For SBF – Aortic atresia /HLHS Near-normal Physiology Pulmonary AVFs Miscellaneous Ebstein’s ASD with PS Unroofed CS into LA

10. Symptom complex – guide to PHYSIOLOGY Examination – guide to ANATOMY (Physical findings) Radiology, ECG – add to BOTH

11. TOF PHYSIOLOGY? What is

12. TOF PHYSIOLOGY Cyanotic CHD with decreased PBF having 2 key components anatomically Severe PS – Decreasing PBF Large VSD – with right to left shunt due to outflow obstruction ( Acyanotic TOF not included)

13. TOF PHYSIOLOGY Cyanotic CHD with decreased PBF having 2 key symptoms Physiologically History of Spells History of Squatting No CHF symptoms

14. Cyanotic CHD with Decreased PBF

15. Cyanotic CHD with Decreased PBF

16. Cyanotic CHD with Decreased PBF

17. TOF

18. “ Tetralogy of Fallot ” History 1671: First reported by Niels Stenson a.k.a Nicholas Steno 1777; 1784; 1839; 1866; 1872 Similar Case reports

19. 1888: Etienne Louis Arthur Fallot Anatomic diagnosis at bedside Confirmed at postmortem Coined term Tetralogie (Fr.)

20. 1894: Pierre Marie (French), first used term “ Tetralogie de Fallot ” 1924: Maude Abbott , first used term “ Tetralogy of Fallot ” & “ Fallot’s Tetralogy ”

21. Pathology Van Praagh called TOF “ Monology of Stenson ” Central pathology – Underdevelopment/ hypoplasia of Subpulmonary infundibulum Gives rise to 4 components of ‘ tetralogy ’ Obstructive RVOT Large Malaligned VSD Aortic override Dominant RV hypertrophy

22. Pathology Van Praagh called TOF “ Monology of Stenson ” Central pathology – Underdevelopment/ hypoplasia of Subpulmonary infundibulum Gives rise to 4 components of ‘ tetralogy ’ Obstructive RVOT Large Malaligned VSD Aortic override Dominant RV hypertrophy

23. TOF 1 in 3600 live births M=F

24. Natural History Survival 66% 1 st yr 50% 3 rd yr 25% 1 st decade Poor survival with PA 50% 1 st yr 10% 1 st decade

25. Symptoms/Presentation Cyanosis 1-2 weeks after birth More severe the PS, earlier the presentation Hypercyanotic Spells 2 months to 2 years of age Exertional dyspnoea Older child Squatting To alleviate a spell or dyspnoea

26. Physical Exam Physically underdeveloped Cyanosis (Depending on PBF) Pulse NORMAL (irrespective of PS severity) Wide PP – only in Large MAPCA/Severe AR

27. Physical Exam JVP NORMAL (Height and waveform) (RAP stays normal unless significant TR present)

28. Physical Exam Palpation RV impulse Gentle; like normal neonatal RV; but stays like that even as child grows 4 th LICS 5 th LICS & Subxyphoid (if Sub- Infundibular stenosis )

29. Physical Exam Palpation LV impulse ABSENT (Conspicuous feature) Absent even if MAPCAs present

30. Physical Exam Palpation 2 nd / 3 rd LICS A2 maybe palpable Left upper ICS (Not right) (due to hypoplastic PA)

31. Physical Exam Palpation Right sternoclavicular joint pulsation Right sided Aortic arch No thrill due to RVOTO BF goes uninterrupted to dilated Aorta

32. Physical Exam Auscultation Aortic area (2 nd RICS) Loud aortic EC from aortic root Maximum in expiration Pulmonary area Very delayed and soft P2 EC and P2 almost inaudible (Bicuspid PV – decreased mobility)

33. Physical Exam Auscultation 3 rd LICS Superficial murmur starting with S1 Duration and intensity decreases with severity of PS No S4 (RA contraction not forceful, RAP normal) No S3 (No RVF)

34. Physical Exam Auscultation Continuous murmurs In case of Pulmonary atresia /MAPCAs AR murmur ± PR murmur ±

35. ECG P wave Height normal, peaked Duration short (LA underfilled ) PR – Normal

36. ECG QRS RAD (Like newborns) Clockwise depn Normal duration No notching RVH Tall R in V1 Sudden transition V1-2 Q in V5,6 - PBF

37. ECG T wave Maybe upright/inverted Deep inversion rare (RVSP never suprasystemic )

38. CXR

39. CXR Reduced PBF markings Lacy appearance in Pulmonary Atresia Dilated Asc Ao Rt Ao arch 20-30%

40. CXR Coer -en-Sabot Heart resembling a wooden boot Concave PA bay Small underfilled LV above a horizontal IVS Concentric RVH

41. CXR Coer -en-Sabot Intrauterine life LV is normal – so boot shape develops after 1-2 mos of birth TOF-PA – Boot even in neonates if low PBF

42. Dorv-vsd-ps

43. DORV Exact incidence unknown – Less than TOF Subaortic VSD 40-50% DORV PS 40-70% Subaortic VSD

44. DORV-PS History Physical Exam CXR Same as TOF

45. DORV-PS Exceptions If restrictive VSD present ( Subaortic stenosis ) Long decrescendo systolic murmur at LPS area (obligatory flow murmur) ECG - LVH

46. DORV-PS Differentiation from TOF ECG PR Prolonged Counterclockwise depn RVH but no sudden transition

47. D- tga – vsd – ps

48. D-TGA 1 in 2500-5000 live births M>F 4:1 VSD is most common communication PS (LVOTO) present in 15%

49. Symptoms/Presentation Cyanosis Since birth – 1 st day of life Hypercyanotic Spells May be present occasionally Squatting Rare

50. Natural History Mortality rate in TGA without PS 30% 1 st week 50% 1 st month 90% 1 st year Better survival with PS – may survive adolescence

51. Physical Exam Birth weight > normal (Contrast to other CHDs) Deep Cyanosis Scalp & Arm varicose veins (Systemic volume overload with desaturated blood)

52. Pulse Full volume bounding pulse Warm extremities JVP Elevated RAP with dominant A wave (Systemic volume overload with desaturated blood)

53. Palpation RV impulse gentle at birth Soon after 1 week – Prominent RV impulse (Systemic volume overload with desaturated blood) Rt sternoclavicular impulse – Rt arch (11-16% in TGA-VSD-PS) Just like TOF

54. Auscultation Just like TOF

55. ECG P wave Tall , Peaked ( Hypervolemic RA) RAD, RVH T Usually positive in ALL precordial leads Taller in right precordial leads Counterclockwise depn

56. CXR Thymic shadow absent (after 12 hrs of birth) Characteristic narrow pedicle (egg on side) ABSENT in severe PS – due to dilated right anterior aorta CXR like TOF

57. l - tga – vsd – ps

58. L-TGA 1 in 13000 live births M>F 1.5:1 VSD 80% L-TGA PS 50% L-TGA 80% of PS a/w VSD

59. Symptoms/Presentation Cyanosis appearance according to PS severity Spells and squatting uncommon Older adults – Stokes-Adams & Syncope (High degree AV blocks)

60. Natural History Better survival with VSD-PS – may survive adolescence

61. Physical Exam Like TOF

62. Pulse Normal Bradycardia /Blocks JVP Normal 1 st /2 nd /3 rd degree AV blocks

63. Palpation IVS almost vertical and parallel to left sternal border Morph. RV – anterior & left position forming apex – Systolic RV Impulse Morph. LV – posterior & right position behind sternum – LV Impulse non-palpable (even if enlarged) Ao EC & A2 palpable 2 nd LICS

64. Auscultation Just like TOF In case of blocks Soft S1 – in 1 st degree AVB Variable S1 – High degree AVB

65. ECG AV Blocks maybe present CHB – ventricular activation sequence normal; QRS narrow LAD (d/t LAFB) RVH

66. Q /q Present in right precordial leads / absent in left ( Septal activation right to left directed) Present in III, avf (III> avf ) / absent in I, aVL ( Septal activation superiorly directed) T Usually positive in ALL precordial leads Clockwise depn

67. CXR Thymic shadow absent Ao & PA side by side Ao left and Anterior Straight left border Hump shaped heart RPA and LPA at same level

68. Tricuspid atresia – ps

69. Tricuspid Atresia (TA) 1 in 17000 live births 90% TA No TGA 90% have Restrictive VSD – Physiologically PS 10% TA TGA 90% have no PS – Increased PBF

70. Symptoms/Presentation Just like TOF

71. Natural History TA-NRGA-PS 80% mortality in 1 st yr Already restrictive VSD – decreases in size and closes! (Like a PM-VSD!) Acquired Pulmonary atresia without embryological collaterals – fatal!

72. Physical Exam Like TOF No left precordial bulge – RV underdeveloped

73. Pulse Normal JVP Height increased A prom – PFO/Restrictive ASD/ Decr LV compliance V prom – MR

74. Palpation IVS almost vertical and parallel to left sternal border Systolic LV Impulse (present even if low PBF) RV Impulse non-palpable

75. Auscultation Single S1 (M1) Single S2 (A2); P2 soft & delayed – maybe heard LVS4 if unrestrictive VSD/LVH Obligatory VSD holosystolic murmur 3 rd -4 th LICS Radiates to 2 nd LICS Duration shortens in closing VSD

76. ECG P wave Tall , Peaked (RAE) LAD LVH with adult precordial progression Counterclockwise depn

77. CXR RAE – prominent rt. Upper border Small RV – Flat receding rt. Inferior border LV apex Prominent Ao /small PA

78. Single ventricle – ps

79. Single ventricle (SV) 1 in 20000 live births M>F 2-4:1 80% SLV 10% SRV 10% Indeterminate SLV OC inverted (right); Noninverted (left) TGA present ( Ao from OC; PA from SLV)

80. Symptoms/Presentation Cyanosis since birth Spells and squatting maybe present

81. Natural History SLV 50% mortality before 14 yrs SRV 50% mortality before 4 yrs

82. Physical Exam Like TOF

83. Pulse Normal JVP Normal V prom – if Rt AV valve regurgitant

84. Palpation Systolic LV Impulse at apex 3 rd LICS – palpable impulse due to inverted OC maybe present

85. Auscultation Like TOF

86. ECG P wave Tall , Peaked (RAE) Inverted OC – RAD, Clockwise depn Noninverted OC – LAD, Counterclockwise depn Stereotyped rS or RS complexes V2-V5 Tall R in V1 despite LVH

87. CXR Non-inverted OC Doesn’t form right border – just like D-TGA LV apex Characteristic waterfall appearance of RPA – NOT present in PS – Low PBF

88. CXR Inverted OC Form left border – just like L-TGA Maybe visible as convexity on left Left straight border LV apex

89. APPROACH?

90. Incidence acccording to age and natural history Age of presentation? Survival?

91. PRESENTATION Timing of cyanosis appearance? Characteristic spells/squatting?

92. Physical Exam LV or RV predominent ?

93. ECG LAD/RAD Clock/ Counterclock LVH/RVH AV Blocks

94. CXR Less helpful LV/RV apex Left Straightening