1. Ventricular septal defects (VSDs) are one of the most common congenital heart defects, accounting for 20-30% of cases in India. 2. The natural history and progression of a VSD depends on factors like its size, location, and the development of pulmonary hypertension. 3. Small VSDs have over a 50% chance of spontaneous closure by age 5, while larger defects often require surgical intervention. Without treatment, complications can include congestive heart failure, pulmonary vascular disease, bacterial endocarditis, and aortic regurgitation.

1. PATHOPHYSIOLOGY,
HEMODYNAMICS
AND NATURAL
HISTORY OF VSD

3. EMBYOLOGY OF IVS

5.  Parts of IVS :
- Membranous septum: Ventriculoatrial + Interventricular components
- Muscular septum: Inlet septum(lightly trabeculated)
Trabecular septum(heavily trabeculated)
Infundibular septum(non-trabeculated)

8.  VSD - m.c. congenital malformation of the heart(excluding BAV) – 20-30% of children in India with CHD
- Saxena, et al .: Indian Guidelines for Management of CHDs - Annals of Pediatric Cardiology / Volume 12 / Issue 3 / Sept-Dec 2019
 Classification of VSD :
- initiated by Soto et al in 1980
- further modified by Anderson, VanPraagh, Casteneda and others

9. Morphologic Classification of Ventricular Septal
Defect

10. PATHOPHYSIOLOGY
Left  Right shunt
Large pulmonary flow(↑Qp)
LA/LV Enlarged (Stage I)
↑Qp with PAH
Biventricular Enlargement (Stage II)
Severe PAH(Muscle hypertrophy + Intimal proliferation and fibrosis)
Shunt reversal (R L) LA/LV Normal size (Stage III)

11. Factors that influence the hemodynamics of VSD
 The size of the VSD
 Pressure gradient across RV/LV
 Pulmonary vascular resistance
 VSD may not be apparent at birth because of the nearly equal pressures in the right and left
ventricles and a lack of shunting.
 With increasing shunt corresponding to the increasing pressure difference between the ventricles,
these defects become clinically apparent.

13. RVSP PA PVR SHUNT HEMODYNAMICS
RESTRICTIVE VSD
< 1/3rd of Ao Orifice
NORMAL NORMAL NORMAL SMALL(1.5 : 1)
SYSTOLIC
NORMAL (LV PRESSURES are not
transmitted to RV)
MOD.RESTRICTIVE
VSD
1/3rd - 3/4th of Ao
Orifice
> NORMAL SUB-
SYSTEMIC
LOW
VARIABLE
MODERATE(1.5-2.2 : 1)
SYSTOLIC,DIASTOLIC
(LV VOO)
LV -↑VOO
RV -↑POO
NON-RESTRICTIVE
VSD - HIGH &
VARIABLE PVR
≥ 3/4th of Ao Orifice
RVSP ≈ LVSP
COMMON
CHAMBER
PA ≈ Ao HIGH
VARIABLE
PERSISTENTLY LARGE
(>2.2 : 1)
PVR dependent FLOW
LV -↑↑↑VOO
-SYSTOLIC DYSFUNCTION
RV -↑↑↑POO(SYSTEMIC AFTERLOAD)
PVR-HIGH
NON-RESTRICTIVE
VSD – HIGH &
PVR
RVSP > LVSP PA > Ao HIGH
FIXED
RIGHT LEFT EISENMENGERISATION of pulmonary
vasculature

14.  Restrictive VSD - Small (≤1.4 : 1) shunt due to significant pressure gradient between LV
and RV(pulmonary-to-aortic systolic pressure ratio < 0.3)
 Moderately restrictive VSD - moderate shunt (Qp/Qs of 1.4 to 2.2 : 1) with a
pulmonary-to-aortic systolic pressure ratio <0.66
 Large or nonrestrictive VSD - large shunt (Qp/Qs > 2.2) and a pulmonary-to-aortic
systolic pressure ratio >0.66.
 Eisenmenger VSD has a systolic pressure ratio of 1 and Qp/Qs less than 1 : 1 or a net
right-to-left shunt.

15. CLINICALLY
 RESTRICTIVE VSD :
- Asymtomatic and lives long
- Systolic murmur
- CXR and ECG may be completely normal
- IE is a usual risk d/t effect of shunt jet on STL
- More chances of Spontaneous closure

16.  MODERATELY RESTRICTIVE VSD :
- Symptomatic d/t ↑Qp – Easy fatiguability
Cough while feeding
Excessive Sweating
Restless on recumbent position and poor sleep
Gets better with Isotonic exercise d/t fall in SVR
- Delayed onset of murmur because delayed fall in PVR and can lead to CCF
- Thrill and Hyperactive precardium

17. - CXR shows Cardiomegaly, increased pulmonary vascularity with prominent PA segment is suggestive of
significant left-to-right flow.
- ECG shows LV VOO, LVH, LAE or BiVH
- Risk of IE and CCF because of LV VOO
- Rarely reaches adulthood, if not intervened

18.  LVH – Voltage criteria ( S in V1 + R in V5/V6 > 35mm or R in V5/V6 > 25mm)
 Left Axis Deviation
 LV strain pattern – ST depressions in V5/V6 with corresponding ST elevations in V1/V2/V3,
U waves in V1-V4

19.  Radiological features : Based on grades of PAH
Grade Mean PA
pressure
Systolic PA
pressure
Pacifico classification
(Ratio of PA systolic &
systemic systolic)
Radiological features
Mild 25-40 25-49 1/3-1/2 MPA dilatation
Moderate 41-55 50-69 1/2- 2/3 MPA dilatation
Rt Descending PA dilatation (>14-16 mm)
Mild peripheral pruning
Severe >55 >70 >2/3 Severe MPA dilatation ( +calcification)
Severe Hilar prominence
Severe pruning
RV enlargement ( Loss of retrosternal space)

20. MPA dilatation
Rt Descending PA dilatation
Mild peripheral pruning

21. Severe MPA dilatation ( +calcification)
Severe Hilar prominence
Severe pruning
RV enlargement ( Loss of retrosternal space)

22.  Non-Restrictive VSD :
- Present in infancy with CCF
- Symptomatology - Poor growth and development
Laboured breathing
Frequent URTI
Difficulty feeding and diaphoresis
Dyspnoea and irritability on lying down-improves with sitting

23. Suck-Rest-Suck cycles
Wakes up and
starts feeding
Feeds short of
satisfaction d/t
dyspnoea
Exhausted
Falls asleep
Hungry infant

24. EISENMENGER’S SYNDROME
 Regulation of shunt through a Non-restrictive VSD with amelioration of symptoms is almost always a
result of rise in PVR    Eisenmenger’s syndrome
 Victor Eisenmenger first identified and published in 1897”Congenital Defects of the Ventricular
Septum”
 Maude Abbott, a Canadian physician, named the condition as Eisenmenger’s complex(1936)
 Paul Wood, a British Cardiologist, defined this pulmonary HTN with reversed shunt as Eisenmenger’s
syndrome(1958)

25. It is a multisystem disorder involving :
 Red cell mass, Hemostasis
 Systemic vascular bed
 CNS
 Bilirubin kinetics
 Coronary circulation and Myocardium
 Uric acid Clearence
 Kidney
 Respiratory system
 Digits and long bones
 Gynecologic endocrinology

26. PATHOPHYSIOLOGY
Right  Left shunt
Cyanosis + ↓Tissue Oxygenation
Arterial Hypoxemia
Adaptive Erythrocytosis
↑ Hematocrit
↑ RBC turnover & Hemolysis
Indirect Bilirubinemia+Gall Stones
EXTRAMURAL CORONARY ECTASIA
Iron Deficiency(≤ 4 yrs)
CEREBRAL VENOUS THROMBOSIS
Paradoxical Emboli
STROKE
Thrombocytopenia(≥ 50yrs)
+
Abnormal vWF
Muco-cutaneous bleeding
Easy Bruising, Epistaxis,
Gingival bleeding, Menorrhagia,
PULM.HEMORRHAGE(MOST SERIOUS)
SUDDEN DEATH
↑ Shear stress in blood vessels
↑ NO,PGs
SYSTEMIC VASCULAR DILATION
SYNCOPE
Dilation of Hilar Arterioles +
Glomerular Capillaries
↑ PGDF,TGF β
PROTENURIA + GLOMERULOPATHY
Remodelling of
Coronary Microvasculature
↓ CORONARY VASCULAR
RESERVE
CLUBBING+HYPERTROPHIC
OSTEOARTHROPATHY
Hyperuricemia
Renal Calculi,Gouty Arthritis

28. GERBODE DEFECT ~0.08% of CHD
 LV–RA communications - congenital >> acquired-Post-MI, trauma, surgical, IE
 First mentioned in 1838 by Thurnam J. On aneurisms of the heart with cases(Autopsy report)
 First diagnosed by Kirby et al in a living patient directly on O.T table,18 Jan.1956 and closed it
successfully through right thoracotomy by inflow occlusion + Hypothermia
 In 1958, Gerbode et al successfully performed surgery on five patients with this anomaly and named
it Gerbode defect
 Caused by an anatomic deficiency of the membranous septum
The Gerbode Defect: Left Ventricular to Right Atrial Communication—Anatomic, Hemodynamic, and Echocardiographic Features - SILBIGER, ET AL - ECHOCARDIOGRAPHY: A Jrnl.
of CV Ultrasound & Allied Tech - 2009

29. Modified Riemenschneider and Moss Classification
1/3rd cases associated with other anomalies – most common being ASD(PFO/Secumdum ASD)

30. Aneurysmal transformation – Wu et al
Morphogenetic process for Infra-valvular shunts

31. LV  RA
Large Systolic ∆ + Small Diastolic ∆
SHUNT depends on Size & PVR
Large Shunt
RA/RV Enlarged
↑ RV preload  LV
LA/LV Enlarged
Severe PAH may develop but uncommon
Biventricular overload
Acute/Chronic Heart Failure
RL shunt caused by
(1) Diastolic flow reversal across defect (RALV)
(2) continuous RALA shunt across PFO/OS-ASD

32.  Asymptomatic to severe heart failure
 Characteristic murmur : loud, harsh pansystolic, Grade III–VI, getting softer with inspiration, radiationing
posteriorly and often associated with a thrill along the left sternal border –
SEA GULL MURMUR
 Raised JVP, liver pulsation, and peripheral edema indicating RHF

34. NATURAL HISTORY
 Refers to the progression of a disease process in an individual over time, in the absence of treatment
 Spontaneous closure
 Premature death
 Pulmonary vascular disease
 Development of aortic incompetence
 Bacterial endocarditis
 Development of infundibular PS

35. Spon Closure Rate
 Rate of spontaneous closure depends on SIZE and LOCATION of VSD
 Muscular VSDs are more likely to close spontaneously, especially if they are not large
 Small VSDs have a >50% chance of spontaneous closure by 5 years
>80% chance by adolescence
Saxena, et al .: Indian Guidelines for Management of CHDs - Annals of Pediatric Cardiology / Volume 12 / Issue 3 / Sept-Dec 2019

36.  Perimembranous VSDs (accounted for most of the moderate to large VSDs)
39% required surgical closure
29% closed spontaneously by 6 years of age
 Muscular VSDs – 3% required surgical closure
69% closed spontaneously by 6 years of age
The natural history of ventricular septal defects - S W Turner, S Hunter, J P Wyllie

37.  Most of the VSDs(~75%) close spontaneously within the first two years of life
 Afterwards, the chance of spontaneous closure diminishes remarkably but extend till adolescence.
 Muscular and membranous VSDs with diameters < 6 mm have the best chance of spontaneous closure
Spontaneous closure of ventricular septal defects in the first year of life - Lin MH et al - J Formos Med Assoc. 2001

38. Age-wise Probability of Spontaneous closure of Small VSD :
 34% by 1 year
 67% by 5 years
 75% by 10.5 years

39. Mech of closure
 Adherence of tricuspid leaflet , or chordal tissue to the edges of VSD.
 Growth & hypertrophy of septum around the defect
 Negative pressure effect exerted by a high velocity stream flowing through the
defect
 Ventricular septal aneurysm
 Prolapse of aortic cusp
 Intrusion of a sinus of Valsalva aneurysm

40. VSD unlikely to close
 Sub-pulmonary
 Juxta-arterial
 Inlet
 Mal-aligned
 Gerbode defect
 Very large
Saxena, et al .: Indian Guidelines for Management of CHDs - Annals of Pediatric Cardiology / Volume 12 / Issue 3 / Sept-Dec 2019

41. Premature death
 About 10% of children with large VSDs die in 1st year, primarily due to congestive heart failure Saxena,

42. Pul vascular disease
In the historic series of Dr. Paul Wood, 52% of patients with large VSD developed irreversible pulmonary
vascular disease with the onset in infancy in four-fifths of them
 Common with Subpulmonary VSD
 Chances of development of PVD with age (PVR > 8 U.m2)
YR Probability
10 yr 10 %
20 yr 50 %
30 yr 80 %
40 yr 100 %

43. Updated clinical classification for PAH associated with
CHD, Nice, France, 2013.

44. Development of AR – seen in 6%
Mechanism :
 Lack of support to aortic annulus : Diastolic prolapse of unsupported cusp.
 Venturi effect : Cusp is sucked during systole
More with Subaortic/ Juxtaarterial VSD and Smaller VSD

45. Bacterial endocarditis : 2-3 decade, on right side
 Among congenital heart disease, VSD is the most frequent anomaly in right- sided IE
 One of the important indications for VSD closure
 The incidence of IE among ventricular septal defects (VSD) was 0.2%- 2%
 Baumgartner et al.Guidelines for the management of grown- up congenital heart disease (new version 2010). Eur Heart J. 2010.

46. Development of infundibular PS : 13 % pts
Gasul Syndrome :
 VSD with acquired PS, Gasul found that about 5- 10 % VSD patients develop PS in follow up(JAMA
1957, circulation 1963)
 Progressive right ventricular outflow tract obstruction (Gasul phenomenon) may develop in 13% and
aortic regurgitation (AR) in 6% of patients