Congenital Heart Defects Functional Overview

1. Congenital Heart DefectsFunctional Overview Dr. Yasser Salem

3. Objectives • Obstructive lesions right or left • Mixing lesions • Shunt lesions left to right or right to left • Univentricular physiology • Miscellaneous • Anomalies of coronary arteries • Vascular ring

4. Obstructive cardiac lesions Acyanotic Cyanotic

5. Obstructive cardiac lesions • low OXYGEN Enough blood, just not enough oxygen in the blood COMPLEX CARDIAC LESIONS = MIXING LESIONS • low BLOOD Enough oxygen, just not enough blood flow OBSTRUCTIVE CARDIAC LESIONS • COMBINATION

6. Left sided obstructive lesions

7. Left sided obstructive lesions Increased flow Backward effects Pulmonary venous congestion Increase RV afterload RV hypertrophy and failure Systemic venous congestion Forward effects Decrease peripheral tissue perfusion Decrease coronary perfusion Myocardial ischemia

9. Left sided obstructive lesion • Aortic stenosis • Subvalvular (SAM, Pompe) • Valvular congenital stenosis • Supravalvular (Aortic coarc., hypoplastic arch) • Mitral stenosis • Subvalvular (Shone’s) • Valvular congenital stenosis • Supravalvular (core triatriatum)

11. Shone’s anomaly

12. Core triatriatum

13. Left sided obstructive lesion • Hypoplastic left heart syndrome (HLHS) • Tricuspid atresia with transposed great arteries • Double-inlet left ventricle • IAA • DORV (some variations)

15. Right sided obstructive lesions

16. Right sided obstructive lesions Backward effects Pulmonary venous congestion Increase RV afterload RV hypertrophy and failure Systemic venous congestion Forward effects Decrease peripheral tissue perfusion Decrease coronary perfusion Myocardial ischemia Decrease pulmonary perfusion (lung oligemia) CYANOSIS

17. Right sided obstructive lesions • Tricuspid atresia • Pulmonary atresia with IVS • TOF with pulmonary atresia • Severe Ebstein’s anomaly of the tricuspid valve • Critical PS • DORV (some variations)

19. sided obstructive lesion Right Left • Aortic stenosis • Subvalvular (SAM, Pompe) • Valvular congenital stenosis • Supravalvular (Aortic coarc., hypoplastic arch) • Mitral stenosis • Subvalvular (Shone’s) • Valvular congenital stenosis • Supravalvular (core triatriatum) • Pulmonary stenosis • Tricuspid stenosis

20. Right sided obstructive lesion • Pulmonary stenosis • Subvalvular (Fallot’s tetralogy) • Valvular congenital stenosis or atresia • Supravalvular (hypoplastic pulmonary arteries) • Tricuspid stenosis • Subvalvular (DCRV, Ebestien) • Valvular congenital stenosis • Supravalvular (eustachian valve)

22. Eustachian valve

23. Double Chamber Right Ventricle(DCRV)

25. Mixing lesions • Defects with mixing of oxygenated and deoxygenated blood • Partial desaturation lead to compensatory in red cell mass and increase 2,3 DPG with increase in blood viscosity.

26. Left sided obstructive lesions • Hypoplastic left heart syndrome (HLHS) • Tricuspid atresia with transposed great arteries • Double-inlet left ventricle • IAA • DORV (some variations)

27. Left sided obstructive lesions • Complete mixing of systemic and pulmonary venous return • Ventricular outflow directed primarily to the PA • Systemic blood flow (Qs) • Largely by right-to-left ductal shunting • Dependent on the relative PVR and SVR • Systemic outflow obstruction is poorly tolerated • Usually accompanied by signs or symptoms of shock

28. Left sided obstructive lesions • Maintain preload at maximum • Maintain afterload at maximum • Maintain contractility in neonates at maximum • Maintain below maximum contractility in older patients • Relative bradycardia is preferred not in neonates Quick guide to pediatric cardiopulmonary care, edwards

29. Right sided obstructive lesions

30. Right sided obstructive lesions • Tricuspid atresia • Pulmonary atresia with IVS • TOF with pulmonary atresia • Severe Ebstein’s anomaly of the tricuspid valve • Critical PS • DORV (some variations)

31. Right sided obstructive lesions • Complete mixing of systemic and pulmonary venous return • Ventricular outflow predominantly directed out the aorta • Low pulmonary blood flow (Qp) in single-ventricle patients implies an obligate right-to-left shunt (generally atrial level) • Clinical consequences of low Qp are variable

33. Mixing lesions • Qp/Qs dependent upon PVR SVR balance • Hypoxemia and its consequences Adjust PVR SVR balance to gain optimal oxygen delivery

34. Obstructive lesions • Qp decreased • Hypoxemia • RV hypertrophy • RV dysfunction • TR • Qs decreased • Low CO • Hypotension • Coronary perfusion decreased • LV failure Avoid SVR decrease Maintain preload Maintain PDA patency • Avoid increase PVR • Hyperoxia • Hypoventilation • Avoid decrease PVR • Relative hypoxia • Relative hypercarbia

35. Objectives • Obstructive lesions right or left • Mixing lesions • Shunt lesions left to right or right to left • Univentricular physiology • Miscellaneous • Anomalies of coronary arteries • Vascular ring

36. Shunt lesions • Shunts may intracardiac or extracardiac • Large shunts are non restrictive with low pressure gradient across • Small shunts are restrictive with high pressure gradient across

37. Left to right shuntFactors affecting shunt flow Ventricular or Great artery level Atrial level Relative compliance Right vs Left ventricle Pressure gradient between chambers or arteries Size of defect Ratio of PVR to SVR Blood viscosity

38. Left to right shuntPathology of shunt flow Atrial or ventricular shunts Great artery shunts All shunts ↑RV filling ↑Pulmonary blood flow ↑LA and LV blood flow ↓Diastolic BP ↓Coronary perfusion pressure ↑RVEDV and ↑RVEDP Pulmonary edema ↑LVEDV and ↑LVEDP RV failure ↑PVR Myocardial ischemia LV failure Pulmonary hypertension Shunt reversal Eisenmenger’s syndrome RV hypertrophy Pressure RV > LV

39. Left to right shuntPathology of shunt flow • Avoid increase in pulmonary flow • Avoid decrease in systemic flow • Avoid extensive diastolic hypotension • Avoid increase in total blood volume • Avoid decrease in PVR • Enhance the use of vasoconstrictors

41. Pulmonary artery banding

42. Pulmonary artery banding • Good banding • High pressure gradient across band by echo • Non-congested lung fields

43. Objectives • Obstructive lesions right or left • Mixing lesions • Shunt lesions left to right or right to left • Univentricular physiology • Miscellaneous • TGA • Anomalies of coronary arteries • Vascular ring

44. Transposition of great arteries • Mixing is mandatory for life • Left ventricle mass and • function • Coronary anatomy

45. Coronary Anomalies ALCAPA

46. Vascular ring

47. Vascular ring AIR

50. Determinants of cardiac output preload Afterload Heart rate CNTRACTILITY CARDIAC OUTPUT Arterial O2 content OXYGEN DELIVERY OXYGEN extraction Venous saturation