Left-Right Shunt Natural history & Principles of Management

1. Left-Right ShuntNatural history & Principles of Management Drranjith mp

2. Ventricular Septal Defect

3. Incidence • Most common congenital heart defect in children • Incidence is 8 per 1000 live births • Echo studies- 5 to 50 per 1,000 newborns Ooshima A et al. Cardiology 1995;86:402-406. • No sex preference , except in subarterial defect

4. Racial variation ASIAN WESTERN • Doubly commited subarterial • Multiple ventricular septal defects are rare • Doubly-commited subarterial defect requiring repair is 30% • Muscular defects • 10% in the west • 5% in western Ferreira Martins JD et al.Cardiol Young 2000; 10: 464–73.

5. Ventricular Septal Defect • Pathologic anatomy of IVS

6. Ventricular Septal Defect • Soto et al classification of VSD • Perimembranous (membranous/ infracristal )-70-80% • Muscular- 5-20% • Central- mid muscular • Apical • Marginal- along RV septal junction • Swiss cheese septum – multiple defects • Inlet/ AV canal type-5-8% • Supracrital (Conal/ infundibular/subpulmonary/doubly committed subarterial)- 5-7% Benignosotoet al. Br HeartJ 1980; 43: 332-343

7. Hemodynamic classification • Restrictive- less than one third of aortic root • LVSP > > RVSP • Pulm /Aortic systolic pressure ratio < 0.3 • Qp / Qs<1.4:1 • Moderately restrictive • RVSP high, but less than LVSP • Qp/Qs 1.4:2.2 • Non restrictive - The size of aortic orifice • RVSP , LVSP, PA Aortic systolic pressures are equal • Qp/Qs >2.2 • Flow determined by PVR

8. Malalignment type of VSD • Anterior more common than posterior • Usually involves the infundibular septum • Occurs as if there is a door that moves round on a hinge

9. Natural History of VSD • The outcome and natural history influenced by • Position & Size • Number of defects • Anatomic structures in the vicinity of the defect • Association of other malformation • Age at which the defect is recognized • Sex of the patient

10. Natural History of VSD • Cardiac failure • Spontaneous diminution in size or closure • Right or Left ventricular outflow tract obstruction • Aortic regurgitation • Pulmonary vascular obstructive disease • Infective endocarditis

11. Cardiac failure • Rare in small VSD as size limits the L-R shunt • In large VSD the relative resistances of the systemic and pulmonary circulations regulate flow • Shunt occurs mainly in systole • Shunt directly to PA • Enlargement of LA, LV,PA

12. Cardiac failure • After birth decline in PVR to adult level by 7to 10 days • In large VSDs, the rate of this process is delayed • Small VSD the shunt is small & remain asymptomatic • Moderate sized VSD symptoms by 1to 6 months • Rarely, adults present with new exercise intolerance .) Rudolph AM, et al.Pediatrics 1965;36:763-772.

13. Cardiac failure • Large VSD congestive heart failure in first few weeks • Risk for recurrent pulmonary infection high • If survives without therapy - pulmonary vascular disease develop in the first few years of life • Symptoms “get better” as Qp/Qs returns to 1:1 • Intervention at this time - a shorter life expectancy than if the defect were left open Fuster V, et al.Cardiovasc Clin. 1980;10:161–197.

14. Spontaneous diminution in size • Occurs in both perimembranous and muscular • Closure is documented in the fetus & in the adult • VSD diagnosed in the fetus - 46% closed in utero & 23.1% in the first year, while 30.8% remained patent • In this study 15.8% of defects < 3 mm remained patent in comparison to 71.4% > 3mm at 1yr Nir A et al.PediatrCardiol 1990; 11: 208–10.

15. Spontaneous diminution in size • More frequent in <10 yrs of age • Isolated VSD ( 124 pts) - 34% at 1 yr & 67% at 5 yr • Female predominance • Decreases substantially after 1 year of age Mehta AV et al. Tenn Med 2000; 93: 136–8. Farina MA et al . J Pediatr 1978; 93: 1065–6. Moe DG et al. Am J Cardiol 1987; 60: 674–8.

16. Spontaneous diminution in size • Rare in malaligned VSD • In outlet VSD closure only in 4% • All of the defects closed were initially < 4 mm Tomita H et al. Jpn Circ J 2001; 65: 364–6

17. Mechanisms of spontaneous closure • Different for perimembranous and muscular • Perimembranous • Reduplication of tricuspid valve tissue • Progressive adherence of the septal leaflet of the tricuspid valve about the margins of the VSD • Aneurysmal transformation of the membranous septum (appearance on angiography) • Early systolic click & late crescendo systolic murmur Anderson RH et al . Am J Cardiol 1983; 52: 341–5. Freedom et al. Circulation 1974; 49: 375–84.

18. Mechanisms of spontaneous closure • Muscular- direct apposition of muscular borders • Large subarterial defect don’t close Closure of a perimembranous defect by adhesion of the tricuspid leaflets to the defect margin. Closure of a small muscular defect by a fibrous tissue plug. Closure of a muscular defect by hypertrophied muscle bundles in the right ventricle Closure of a defect in subaortic location by adhesion of the prolapsed aortic valve cusp

19. Right ventricular outflow tract obstruction • Incidence 3% to 7%. • Mechanism:- • Hypertrophy of malaligned infundibular septum • Hypertrophy of right ventricular muscle bundles • Prolapsing aortic valve leaflet • High incidence in • Right sided aortic arch • Horizontal RVOT Nadas AS et al . Circulation 1977; 56(No.2, Suppl. I): 1–87. Corone P et al. Circulation 1977; 55: 908–15. Pongiglione G et al . Am J Cardiol 1982; 50: 776–80. Varghese PJ et al . Br Heart J 1970; 32: 537–46. Tyrrell MJ et al. Circulation 1970; 41 & 42(Suppl. III): 113.

20. Aortic valve prolapse • VSD with direct contact with the aortic valve are most prone to develop AVP • All the perimembranous defects • All doubly committed juxtaarterial defects • Most of muscular outlet defects • Characteristic deformity of aortic cusp-nadir of the cusp is elongated

21. Aortic valve prolapse • RCC (60-70%) , NCC (10-15%) , both in 10-20% • Non-coronary cusp prolapse in perimembranous type • Left coronary cusp prolapse extremely rare • AR may be due to incompetent bicuspid aortic valve • Rarely prolapsed valve cusp may perforate

22. Aortic valve prolapse • Pathogenesis Anatomic factors for normal competence • Leaflet support by diastolic apposition • Infundibular support from below Intrinsic structural abnormality • Progressive discontinuity between aortic valve annulus & media

23. Aortic valve prolapse • Pathogenesis Hemodynamic factor • ‘’Venturi effect’’ • VSD is restrictive, Qp/Qs<2 , absence of PAH Komai H et al.AnnThoracSurg 64:1146-1149, 1997

24. Natural history of Aortic valve prolapse • Unknown exact prevalence (2% to 7%) • Rare before 2 years • More severe - additional volume load • Aneurysm of sinuses of Valsalva may develop Nadas AS et al . Circulation 1977; 56(No.2, Suppl. I): 1–87.

25. VSD with AR- Indian scenario • 362 Patients. 37 (10.2%) had AR • Mean age 13.4 years ( 2-45),male to female ratio 5:1 • 31 (84%) had infracristal & 6 (16%) supracristal VSD • Infracristal VSD-RCC prolapse in 14 (48%) &NCC in 12 (41%) and both RCC and NCC in 3 (11%) • Supracristal VSD - RCC prolapse in 5 (83%),NCC in 1 • Two patients the AR was due to bicuspid aortic valve • PA pressure normal in 26(70.2%), L-R shunt 1.5:1 or less in 23 (62%) • No relationship- severity of AR & location of VSD Somanath HS et al. Indian Heart J. 1990 Mar-Apr;42(2):113-6.

26. Intervention in VSD with AVP • Indicated for both perimembranous and subarterial VSDs when more than trivial AR • Subarterial VSDs >5 mm - closed regardless of AVP • Restrictive perimembranous VSD with AVP but without AI, surgery indications are less clear • Follow up regularly • Surgery is indicated only if AI develops Elgamal MA et al . Ann ThoracSurg 68:1350-1355, 1999 Lun K et al. Am J Cardiol 87:1266-1270, 2001 Gabriel HM et al. J Am CollCardiol 39:1066-1071, 2002

27. Left ventricular outflow tract obstruction • Usually above the ventricular septal defect Etiology:- • Progression of the pre-existing lesion • Acquired Two types:- • Muscular • Fibromuscular

28. Left ventricular outflow tract obstruction • Three major structures are responsible • Posteriorly malaligned outlet septum • Septal deviation ( anteroseptal twist) • Muscular protrusion of the left ventricular aspect of the septum • Anterolateral muscle bundle • Muscular protrusion between LCC & AML- present normally in 40% (Very rarely “Mitral arcade”) • Careful echo assessment of the LVOT should be performed in all cases of VSD before surgery Moene RJ et al. PediatrCardiol 1982;2: 107–14.

29. Pulmonary vascular obstructive disease • Incidence - 5% to 22% • Rare in small & Moderate-size VSDs • Down syndrome – early development of PAH • No overall sex predilection Keith JD et al. Heart Disease in Infancy and Childhood. 1978: 320–79.

30. Pulmonary vascular obstructive disease • Survival rate for patients with VSD by pulmonary artery systolic pressure • 42 men and 37 women, 18 to 59 years (mean 34 yrs) • 67 patients treated medically and 12 surgically • All patients were followed up for 1 month to 25 yrs ( mean 9yrs) The solid line indicates a pressure less than 50 mm Hg (n = 36) Dashed line indicates a pressure of 50 mm Hg or greater (n = 17) Ellis JH 4th et al . Am Heart J. 1987;114:115-205

31. Pulmonary vascular obstruction • Eisenmenger complex, develops in 10% to 15% • most commonly in the 2 nd& 3rddecades of life • common causes of death "sudden" or "unknown“ • Development of pulmonary vascular disease after surgery depends on age at procedure is done • Infants with VSD and increased pulmonary artery pressure - repair between 3 and 12 months

32. Infective endocarditis • 18.7 per 10000 person-years in non operated cases • Operated VSD 7.3 per 10000 person-years • Higher in small defect & lower during childhood • Patients with a proven episode of endocarditis are considered at increased risk for recurrent infection so surgical closure may be recommended Gersony WM et al.Circulation 1993; 87(Suppl. I):I-121–I-126.

33. Arrhythmias • Patients with VSD have a high incidence of arrhythmia • Ventricular tachycardias in 5.7% • Sudden death is 4.0% • SVT, mostly AF, is also prevalent • Age and pulmonary artery pressure are the best predictors of arrhythmias • The odds ratio of serious arrhythmias increases • 1.51 for every 10-year increase in age • 1.49 for 10mm Hg increase in mean PA pressure Wolfe RR et al. Circulation. 1993;87:I89-101

34. Improvement of symptoms in VSD • Closing defect - soft S2, high frequency & shorter murmur • Increasing PVR : increased RV pulsations ,S2 loud & narrow split • Infundibular hypertrophy & resulting decreased L to R shunt : S2 decreases in intensity ,crescendo-decrescendo systolic murmur in the ULSB

35. Indications for Operation • Heart failure not controlled by medical therapy VSD should be operated with in 6 month of life • Qp/Qs is 2 or more surgical closure needed regardless of PA pressure • VSD with PVR more than 4 unit during 6-12 months • VSD with elevated PVR first seen after infancy • Moderate VSD with no size change in childhood

36. Postoperative Sequelae • Right bundle branch block • 33.3% undergoing transatrial repair • 78.9% to 11% in repair via a right ventricular incision • Transpulmonary approach has the lowest incidence • Complete heart block in 1 to 2% • Pulmonary hypertension in (4% ) • Sinus node dysfunction (4%) • Progressive aortic valve insufficiency (16%) Abe T et al . Jpn Circ J 1983; 47: 328–35. Roos-Hesselin JW et al. Eur Heart J 2004;25:1057-1062.

37. Patent Ductus Arteriosus

38. Introduction • Incidence of isolated PDA in term infants - 1 in 2,000 • Female predominance - 3:1 • High incidence- Prematurity, Maternal rubella • Genetic inheritance- Autosomal recessive with incomplete penetrance

39. Natural History of PDA • Congestive heart failure • Infective endarteritis • Pulmonary vascular disease • Aneurysmal formation • Thromboembolism • Calcification

40. Congestive heart failure • CHF resulting from an isolated PDA either develops in infancy or during adult life • HF in infancy usually occurs before of 3 mths of age • Initially left heart failure, later right heart failure • Good response to drugs initially, but is not maintained

41. Infective endarteritis • Major cause of death in earlier era • Incidence - 0.45% to 1.0% per annum • Vegetations usually found at the PA end of the duct • May cause recurrent pulmonary embolism • Infection may also cause a ductal aneurysm Cosh JA. Br Heart J 1957; 19: 13–22.

42. Pulmonary vascular obstructive disease • No definite data on incidence • “Differential cyanosis” • Eisenmenger patients do not tolerate PDA closure

43. Aneurysm of the duct • Described either pre- or postnatally • Likely develops in the third trimester due to abnormal intimal cushion formation or elastin expression • Incidence varies from 1.5% to 8.8% Dyamenahalli U et al. J Am CollCardiol 2000; 36: 262–9. Jan SL et al. J Am CollCardiol 2002; 16: 342–7.

44. Aneurysm of the duct • Complications • Thromboembolism • Dissection • Rupture • Tracheal compression • Left recurrent laryngeal nerve palsy • Pulmonary artery obstruction • Regression can occur, presumably due to thrombosis and subsequent organization

45. Treatment of PDA • As many ducts will eventually close in premature infants approach to treatment is different - preterm infant Vs mature, child • Beyond infancy, closure reported in 0.6% per year • Medical therapy • Treatment of Heart failure • Ductal closure with drugs • Surgical Therapy Campbell M et al.Heart 1968;30:4–13.

46. Ductal closure with drugs • Indomethacin • Rates of success varying between 18% to 89% • Major determinants of success were gestational and postnatal age • Less chance of closure-Extreme prematurity, very low birth weight, and advanced postnatal age • The rate of re-opening is highest in the extreme premature( 1/3) & less than 1/10 those weighing 1500 g Mahony et al. N Engl J Med 1982;306: 506-510.

47. Ductal closure with drugs • Ibuprofen • Comparable rate of ductal closure to Indomethacin • Less effect on renal function • Increased incidence of Pulmonary hypertension Gournay V et al. Lancet 2004;364:1939-1944.

48. Intervention in PDA • Coils closure for <3 mm, >97% success, zero mortality • Larger PDAs - specialized devices • >98% complete closure rate at 6 months

49. Indications for intervention in PDA • Symptomatic moderate or large PDA with L to R shunt • Prior history endarteritis [class1] • Reasonable in small L to R shunt with normal-sized heart chambers when the PDA is audible by auscultation[IIa] • May be considered in bidirectional PDA shunt due to PAH and obstructive pulmonary vascular disease but reversible to pure L to R shunting with pulmonary vasodilators [IIb]

50. Atrial Septal Defect