Pediatric-Cardiology-101.ppt

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Pediatric-Cardiology-101.ppt

  1. 1. PediatricCardiology 101 Misty Carlson, M.D.
  2. 2. DISCLAIMER: This lecture is based on generalizations. In reality, a congenital heart defect (CHD) can act completely different from one patient to the next (eg- classic ToF vs “pink” ToF). There are many more CHDs than what I’ve listed and I hope you can use these principles to help you out with those.
  3. 3. Fetal Circulation For the fetus the placenta is the oxygenator so the lungs do little work RV & LV contribute equally to the systemic circulation and pump against similar resistance Shunts are necessary for survival  ductus venosus (bypasses liver)  foramen ovale (R→L atrial level shunt)  ductus arteriosus (R→L arterial level shunt)
  4. 4. Transitional Circulation With first few breaths lungs expand and serve as the oxygenator (and the placenta is removed from the circuit) Foramen ovale functionally closes Ductus arteriosus usually closes within first 1-2 days
  5. 5. Neonatal Circulation RV pumps to pulmonary circulation and LV pumps to systemic circulation Pulmonary resistance (PVR) is high; so initially RV pressure ~ LV pressure By 6 weeks pulmonary resistance drops and LV becomes dominant
  6. 6. Normal Pediatric Circulation LV pressure is 4-5 x RV pressure (this is feasible since RV pumps against lower resistance than LV) RV is more compliant chamber than LV
  7. 7. 100% 90/  No shunts 60 20/8  No pressure gradients75% 75% 100%  Normal AV valves  Normal semilunar valves 20/ 90/  If this patient was desaturated what would you think?
  8. 8. If you have a hole in the heart whataffects shunt flow?1. Pressure – easy enough to understand2. Resistance – impedance to blood flowRemember, the LV has higher pressure anda higher resistive circuit relative to the RV.Now onto the nitty-gritty …
  9. 9. Congenital Heart Disease (CHD) Occurs in 0.5-1% of all live births Simple way to classify is:  L→R shunts  Cyanotic CHD (R→L shunts)  Obstructive lesions
  10. 10. L→R Shunts (“Acyanotic” CHD) Defects 1. VSD 2. PDA 3. ASD 4. AVSD (or complete atrioventricular canal) May not be apparent in neonate due to high PVR (ie- bidirectional shunt)
  11. 11. L→R Shunts – General Points PDA & VSD ASD  Presents in childhood w/ Presents in infancy w/ murmur or exercise heart failure, murmur, intolerance (AVSD or 1o ASD and poor growth presents earlier) Left heart enlargement  Right heart enlargement (LHE) (RHE) Transmits flow and  Transmits flow only pressure AVSD can present as either depending on size of ASD & VSD component
  12. 12. Increased PBFLeft Heart Right Heart Overload Overload
  13. 13. Pulm vasc markings equal in upper andlower zones Cardiomegaly
  14. 14. Eisenmenger’s Syndrome A long standing L→R shunt will eventually cause irreversible pulmonary vascular disease This occurs sooner in unrepaired VSDs and PDAs (vs an ASD) because of the high pressure Once the PVR gets very high the shunt reverses (ie- now R→L) and the patient becomes cyanotic
  15. 15. R→L Shunts (CCHD)• “Blue blood bypasses the lungs”• Degree of cyanosis varies• Classify based on pulmonary blood flow (PBF) ↑ PBF ↓ PBF Truncus arteriosus  Tetralogy of Fallot Total anomalous pulm.  Tricuspid atresia venous return (TAPVR)  Ebstein’s anomaly Transposition of the great arteries (TGA)Please note: This is a generalization. In reality most of these defects can present withlow or high PBF (eg- ToF with little PS acts more like a VSD with high PBF)
  16. 16. R→L Shunts ↑ PBF  Presents more often with heart failure (except TGA)  Pulmonary congestion worsens as neonatal PVR lowers  Sats can be 93-94% ifThere is unimpeded Equal there is high PBFPBF; thus, extreme pressures pulmonary here too overcirculation.
  17. 17. R→L Shunts ↓ PBF  Presents more often with cyanosis  See oligemic lung fields  Closure of PDA may worsen cyanosisDynamic subvalvular Why are obstruction here causes “Tet spells” pressures equal?
  18. 18. Pulmonary 90% overcirculation Too little 70% PBF70% 99% 60% 99% 99% 99% 70% 60%
  19. 19. Different amounts of PBF (Truncus vs ToF)
  20. 20. Obstructive Lesions Ductal Dependent Non-Ductal Dependent1. Critical PS/AS 1. Mild-moderate AS2. Critical CoA/IAA 2. Mild-moderate CoA3. HLHS 3. Mild-moderate PS Presents in CV shock at  Presents in older 2-3 days of age when child w/ murmur, PDA closes exercise intolerance, +/- cyanosis or HTN (in CoA) Needs PGE1  Not cyanotic
  21. 21. Ductal-Dependent Lesion Without a PDA there is no blood flow to the abdomen and lower extremities. (Blue blood is better than no blood.)
  22. 22. Physical Exam Inspection and palpation  Cardiac cyanosis must be central  Differential cyanosis = R→L PDA shunt  Differential edema/congestion implies obstruction of SVC or IVC  Increased precordial activity  Displaced PMI  RV heave = RV hypertension
  23. 23. Physical exam Lungs  Respiratoryrate and work of breathing  Oxygen saturations Abdominal exam  Liver size Extremities  Perfusion  Edema  Clubbing
  24. 24. Physical Exam Pulses (very important)  Differentialpulses (weak LE) = CoA  Bounding pulse = run-off lesions (L→R PDA shunt, AI, BT shunt)  Weak pulse = cardiogenic shock or CoA  Pulsus paradoxus is an exaggerated SBP drop with inspiration → tamponade or bad asthma  Pulsus alternans – altering pulse strength → LV mechanical dysfunction
  25. 25. Physical Exam  Heart sounds  Ejection click = AS or PS  Mid-systolic click = MVP  Loud S2 = Pulmonary HTN  Single S2 = one semilunar valve (truncus), anterior aorta (TGA), pulmonary HTN  Fixed, split S2 = ASD, PS  Gallop (S3) – may be due to cardiac dysfunction/ volume overload  Muffled heart sounds and/or a rub = pericardial effusion ± tamponade
  26. 26. Physical Exam  Types of Murmurs  Systolic Ejection Murmur (SEM) = turbulence across a semilunar valve  Holosystolic murmur = turbulence begins with systole (VSD, MR)  Continuous murmur = pressure difference in systole and diastole (PDA, BT shunt)
  27. 27. Innocent murmurs Peripheral pulmonic stenosis (PPS)  Heard in newborns – disappears by one year of age (often earlier)  Soft SEM at ULSB w/ radiation to axilla and back (often heard best in axilla/back)  Need to differentiate b/w PPS and actual pulmonic stenosis. PS often associated with a valvular click and heard best over precordium
  28. 28. Innocent murmurs Still’s murmur  Classic innocent murmur  Heard most commonly in young children (3-5 yrs of age) but can be heard in all ages  “Vibratory” low-frequency murmur often heard along LSB and apex  Positional – increases in intensity when pt is in supine position  Also louder in high output states (i.e. dehydration, fever)  Need to differentate from VSD
  29. 29. Innocent murmurs Pulmonary flow murmur  Often heard in older children and adolscents  Soft SEM at ULSB, little radiation; normal second heart sound  Not positional  Need to differentiate b/w mild PS and especially an ASD  Hint: ASD would have a fixed split second heart sound
  30. 30. Innocent murmurs Venous hum  Often heard in toddlers, young children  Low pitched continuous murmur often heard best in infraclavicular area, normal heart sounds  Positional – diminishes or goes completely away when pt in supine position or with compression of jugular vein  Need to differentiate between a PDA
  31. 31. Syndrome Associations Down – AV canal and VSD Turner – CoA, AS Trisomies 13 and 18 – VSD, PDA Fetal alcohol – L→R shunts, ToF CHARGE – conotruncal (ToF, truncus)
  32. 32. Hereditary Diseases Marfan (AD)– aortic root aneurysm ± dissection, MVP, MR, AI HCM (AD) – outflow tract obstruction, arrhythmias Noonan (AD) – HCM, PS DMD/BMD (X-link) – DCM (>12 y.o.) Williams (AD) – supravalvar AS Tuberous sclerosis – rhabdomyoma Romano-Ward – AD LQTS Jervell & Lange-Nielsen – AR LQTS & deafness
  33. 33. Kawasaki Disease (KD) Now the #1 cause of acquired heart disease A systemic vasculitis (etiology-unknown) Tests – CBC, CMP, CRP, ESR, EKG, ECHO Rx – IVIG at 2g/kg and high-dose ASA Prognosis – Coronary artery dilatation in 15-25% w/o IVIG and 4% w/ IVIG (if given within 10 days of fever onset). Risk of coronary thrombosis.
  34. 34. Kawasaki – Clinical criteria Fever for at least 5 days AND 4 of the following 5 criteria:  Eyes - conjunctival injection (ie- no exudate)  Lips & mouth - erythema, cracked lips, strawberry tongue  Hands & feet - edema and/or erythema  Skin - polymorphous exanthem (ie- any rash)  Unilateral, cervical lymphadenopathy
  35. 35. Rheumatic Fever A post-infectious connective tissue disease Follows GAS pharyngitis by 3 weeks (vs. nephritogenic strains of GAS) Injury by GAS antibodies cross-reacting with tissue Dx – JONES criteria (major and minor) Tests – Throat Cx, ASO titer, CRP, ESR, EKG, +/- ECHO Rx – PCN x10 days and high-dose ASA or steroids 2o Prophylaxis – daily po PCN or monthly IM PCN
  36. 36. Rheumatic Fever – organsaffected1. Heart muscle & valves – myocarditis & endocarditis (pericarditis rare w/o the others)2. Joints – polyarthritis3. Brain – Sydenham’s Chorea (“milkmaid’s grip” or better yet, “motor impersistance”)4. Skin – erythema marginatum (serpiginous border) due to vasculitis5. Subcutaneous nodules – non-tender, mobile and on extensor surfaces
  37. 37. In case you haven’t had enough….
  38. 38.  A ductal-dependent lesion One ventricle pumps both PBF & SBF Difficult to balance PBF & SBF
  39. 39. Norwood Procedure  What is the purpose of the BT shunt?  Is there a murmur?  What is your guess for the arterial saturation?
  40. 40. Bidirectional Glenn What is the purpose of the Glenn? Is there a murmur? What is your guess for the arterial saturation?
  41. 41. Fontan circuit What is the path of blood? Is there a murmur? What is your guess for the arterial saturation?

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