Ventricular septal defect (vsd)

vsd

1. ventricular septal defect (VSD)

2. Embryology Heart tube has an arterial ( bulbus cordis ) and venous( sinus venosus ) end Bulbus cordis is divided in prox , middle( conus ) and distal( truncus arteriosus ) one 3 rd During development atria is pushed above and ventricle is pushed down. Proximal 1/3 rd of bulbus cordis is incorporated into primitive ventricle- common ventricular chamber Primitive ventricle-L V Prox 1/3 rd of B.C.- R V Middle 1/3 rd ( conus )of BC-outflow tract

3. Bulvoventricular sulcus form interventricular sulcus Atrioventricular cushion-a cushion developing between atrium and ventricle which forms septum intermedium

4. Ventricular septum Interventricular muscular partition - Growth from floor of common ventricular cavity Bulbur sept - from bulbar ridges that separate great vessels (aka as spiral septum) Membranous septum-proliferation from AV cushion

5. A small portion which separates RA from LV, called Atrioventricular septum Atrioventricular septum- posterior portion of mem . Septum and AV cushion

6. Parts of ventricular septum Inlet septum-separates mitral and TV; extends basally from septal tricuspid annulus and apically upto attachment of tricuspid papillary apparatus. Trabecular septum-extends from tricuspid papillary attachments outward to apex and upward to the horizontal limb of septal band Outlet or infundibular septum, which extends above the superior aspect of septal band to the pulmonary valve. Membranous septum, a relatively small region located at the intersection of trabecular , inlet and outlet septum, lie just beneath the NCC of aortic valve and in close relation to anteroseptal tricuspid commisure .

7. Membranous septum is located below the aortic valve at the junction of right and non coronary cusp Septal leaflet of the TV divide the membranous septum- Pars artrioventricularis -above the STL attachment of TV, and Pars interventricularis -beneath septal tricuspid leaflet

8. TYPE I VSD Conal,Supracristal,Infundibular , Subarterial Maldevelopment of bulbotruncal system Located within infundibular portion of RVOT Superior margin – no muscular tissue Inferior margin – defect is muscular Can extend upto right or sometimes non-coronary cusps of the aortic valve

9. TYPE II VSD Also called Conoventricular defects. Most common (80%) Margins include membranous septum or remnant May have extensions into inlet, outlet or trabecular septum Postero -inferior margin very close to the antero-septal commissure of the Tricuspid valve Can extend upto non-coronary cusp of aortic valve

10. TYPE III VSD AV Canal type / Inlet VSDs Form about – 5% of all VSDs Located posteriorly – subjacent to TV septal leaflet in inlet portion Superior border- may extend to the annulus of tricuspid valve Conduction system at risk – close proximity to AV node

11. TYPE IV VSD Muscle tissue all around the defect May be either anterior, in the inlet septum, mid-muscular or apical May be Single/ multiple Swiss Cheese VSD

12. Etiology

13. Environmental Paternal use of marijuana and cocaine Paternal exposure to paint

14. Physiology of VSD The pathophysiology of a VSD is determined primarily by the direction and amount of flow across the defect size of the defect relative resistances along the pulmonary and systemic vascular beds

15. In small VSD, pressure restrictive L to R shunt across the defect as PVR decreases after birth Usually no signs and symptoms of CHF May close spontaneously

16. Clinical feature

17. Size Small Moderate Large Eisenmenger syndrome PA to aoritc pressure <0.33 0.33 to 0.66 >0.66 >1.0 Qp:Qs <1.4 1.4 to 2.2 >2.2 <1 Clinical features Usually asymptomatic Dyspnea Exercise intolerance Recurrent RTI Symptomatic in infancy Cyanosis and clubbing Clinical findings Only shunt murmur Shunt murmur depends on PVR rather than size Shunt murmur depends on PVR only Cardiac chambers Usually normal Lv , LA, pulmonary A. No RV dilation LV, LA, PA, RV enlargement PA+/- RV enlargement ECG Normal LVH And LAH BVH, LAH RVH, RAD

18. EXAMINATION

19. Heart sounds

20. Murmurs Pansystolic murmur because of shunt Mid-diastolic Murmur Murmur of AR PSM because of TR

21. Pansystolic murmur

22. Mid-diastolic Murmur Flow rumble Signifies large pulm to systemic ratio(>2:1) Follows loud S3

23. Katz- Wachtel phenomenon : Tall diphasic QRS complexes (>50 mm in height) in the mid- precordial leads (leads V2, V3 or V4) typically associated with  Biventricular Hypertrophy.

24. CHEST X-RAY Cardiomegaly : proportional to the volume overload. Mainly LV, LA enlargement . Increased pulmonary blood flow, PAH. RV may not be as enlarged as anticipated as it receives the shunt into its outflow tract.

25. Echocardiography Number , size, and exact location of the defect Estimate PA pressure by using the modified Bernoulli equation Identify other associated defects Estimate the magnitude of the shunt

26. Central ( perimembranous ) VSDs are located at the base of the heart behind the septal leaflet of the tricuspid valve and below the aortic valve

27. Perimembranous VSD- located at the base of heart behind the septal leaflet of TV and below AV ( subcostal left anterior oblique view)

28. Perimembranous Defect is located along rt anterior aspect of aortic outflow tract adjacent to TV ( 9 to 11 o’clock)

29. apical four-chamber view of a patient with a large inlet ventricular septal defect (star) and two separate atrioventricular valves

30. Muscular VSD Mid- septal Apical Anterior Inferor posterior

31. a patient with a large midmuscular ventricular septal defect (star) in an apical four-chamber view

32. ventricular septal defects (star) from the right ventricular perspective of (A) a central ventricular septal defect and (B) an inferior muscular ventricular septal defect; notice that the septal leaflet of the tricuspid valve represents one border of the defect in (A) whereas the defect in (B) has a completely muscular rim; in addition, the defect in (A) is located below the aortic valve (not seen because only the right ventricular structures are seen in the rendered image)

33. Cardiac MRI Black and bright blood imaging provide information about size and shape of VSD and location Measurement of LA and LV volumez Qp /Qs-by calculating stroke volume of of RV and LV

34. catheterization When data from echo. and cardiac MRI is insufficient Shows an increase in oxygen saturation at the right ventricular level and pulmonary artery level, reflecting the left-to-right ventricular shunt Shunt severity Qp and Qs ratio Pressure measurements in cardiac chambers Calculation of PVR and SVR

35. Aortogram for AR, PDA

36. A large VSD during childhood is typically associated with significant left-to-right shunt and eventual development of congestive heart failure. Patients with moderate-sized VSDs can survive to adulthood before detection. Given the gradual development of symptoms in these patients, they may not present until late in the disease course. In these patients, the excess right-sided flow may lead to pulmonary vascular disease and Eisenmenger physiology if left untreated.

37. Endocarditis is a risk because of the presence of a high-velocity, turbulent jet into the right ventricle. Endocarditis most frequently involves the septal leaflet of the tricuspid valve apparatus at the point of jet impact

38. Risk factors for decreased survival include: 1 . Cardiomegaly seen on the chest radiograph 2. Elevated pulmonary artery systolic pressure (> 60 mm Hg and/or more than one-half of the systemic pressure) 3 . Cardiovascular symptoms such as shortness of breath, fatigue, or dyspnea on exertion; and 4 . Progressive aortic insufficienc

39. Pt. with restrictive central VSD can develop double chamber R V- because of high velocity jet hitting R V can cause HTN of free wall leading to hypertrophy and development of prominent RV muscle bundle Gradient across muscle bundle leading RV proximal hypertension.

40. Management

41. Medical mangement Diuretics Ace inhibitor for for systemic afterload reducation in high Qp /Qs Adequate calorie intake in infants -in large VSD

42. Earlier, children with large VSD with HF-pulmonary banding was done as staging procedure Now its done for only complex VSD ( swiss cheese type of VSD, straddling AV valves or double outlet ventricle)

43. 5 operative approaches – RIGHT ATRIAL TRANSPULMONARY TRANSAORTIC RIGHT VENTRICULAR LEFT VENTRICULAR

44. Percutaneous device closure

45. Clamshell Device Cardio SEAL Septal Occluder STARFlex devices Amplatzer device