vsd
DESCRIPTION
VSDTRANSCRIPT
VSD by Dr.JYOTINDRA SINGH
NIMS,HYDERABAD
Ventricular Septal Defect
Henri Roger was the first man to describe a ventricular septal defect, in 1879 he wrote: “A developmental defect of the heart occurs from which cyanosis does not ensue in spite of the fact that a communication exists between the cavities of the two ventricles and in spite of the fact that the admixture of venous blood and arterial blood occurs. This congenital defect, which is even compatible with long life, is a simple one. It comprises a defect in the interventricular septum”
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INTRODUCTION
Isolated VSD - most commonly recognized CHD
2- per 1000 live birth
Forms 20 % of all CHD
50 % when associated with other major defects
75-80% of small VSD’s close spontaneously by late childhood
10-15% of large VSD’s close spontaneously
60% of defects close before age 3, and 90% before age 8
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Roger in 1879 - first described
Eisenmenger – 1897 - autopsy finding
Pathophysiology by Abbott (1936) & Selzer (1949)
1952 – Muller and Danman- pulmonary artery band
1954 - Lillehei and associates – First vsd repair
1956 – Dushane – Transventricular / Stirling – Transatrial
1961 – Kirklin- Repair of VSD in infants
1976 - Baratt-Boyes – deep hypothermia & circulatory arrest
HISTORICAL ASPECT
The primitive cardiac tube has five zones:
the arterial trunk
the bulbus cordis ) the ventricle
the atrium
and the sinus venosus
SVA
V
BV D
A
V
.
VSD occurs during the first 8 weeks of foetal life
3 components – Interventricular muscular partition
- Endocardial cushions
- Bulbar ridges that separate great vessels
EMBRYOLOGY
Four cushions (AVC) have developed at the A/V junction; the superior and inferior cushions willmeet to divide the AV orifice (AVO)into the tricuspid and mitral valves. The inferior septal crest (VS)will aim to meet the divided valve where the cushions fuse.
Formation of IV septum IV septum upwards from the
floor of the bulboventricular cavity,division into rt and lt halves.It meets fused AV cushions and partially fuse with them.
Two ridges rt and lt arise in conical upper part of bulboventricular cavity.fuse with each other to form bulbar septum.
Gap persists between the two-filled by proliferation of tissue from the AV cushions.
Membranous IV septumAnt part separates rt and left ventricles.
Post part separates rt atrium and left ventricle.
This is because the interatrial and interventricular septum don’t meet in the midline.
Ventricular Septum
R
Membranous
Muscular Spiral(Aorticopulmonary)
What if?..............- then you get
the truncal septum fails to fuse with the septal crest?- perimembraneous VSD
the truncal septum is deviated to the PA side?- tetralogy of Fallot
the truncal septum fails to develop?- truncus arteriosus
the ventricular septum fails to reach the AV valve?- AV septal defects
the arterial trunk stays over the RV but does divide?- double outlet RV
the aortic valve pushes up and right instead of the pulmonary?- transposition of the great vessels
the ventricles fail to centralise over the AV valve- double inlet left ventricle (commonest form of single ventricle)
the loop is to the left?- ventricular inversion (RV on the left, LV on the right)
Associated Defects
Left Heart Defects– Aortic stenosis– Coarctation of the aorta
Right Heart Defects– Tetrology of Fallot– Double Outlet Right Ventricle
Truncus Arteriosus
Some single ventricle (e.g. Tricuspid atresia, double inlet left ventricle)
Chromosomal Disorders associated with VSD
Trisomy 21: 40% of T21 will have VSD
Trisomy 13, 18: 18% of T13, 31% of T18 will have VSD
22q11 deletion:– Tetrology of Fallot is most common anomaly – VSD with or without aortic arch anomaly is second most
common
Holt-Oram (Hand-heart syndrome): TBX5 gene found on Chromosome 12
Recurrence risk for VSD based on parental VSD
– Paternal 2%– Maternal 6-10%
The Ventricular Septum
1. Membranous
2. Outflow
3. Trabecular septum
4. Inflow
5. Subarterial / Supracristal
The Ventricular Septum
Ventricular SeptumThe membranous septum-The septal leaflet of the tricuspid valve divides the membranous septum into 2 components, the pars atrioventricularis and the pars interventricularis.1
The muscular septum is a nonplanar structure that can be divided into inlet, trabecular, and infundibular components.
An inlet VSD has no muscular rim between the defect and the atrioventricular valve annulus.
The trabecular septum is the largest part of the interventricular septum. The location of defects in the trabecular septum can be classified as anterior, midmuscular, apical, and posterior
The infundibular septum separates the right and left ventricular outflow tracts. On the right side, it is bordered by the line from the membranous septum to the papillary muscle of the conus inferiorly and the semilunar valves superiorly.
Nomenclature / ClassificationTYPE I- Conal,Supracristal,
Infundibular,Subarterial
TYPE II – Paramembranous
TYPE III-
Inlet/ AV canal type
Type IV –
Muscular
CLASSIFICATION
ROBERT ANDERSON
Perimembranous
Muscular
Doubly committed Juxta arterial defects
Van Pragh
AV canal type
Muscular VSDs
Conoventricular
Conal
Lesion Size• Restrictive VSD
– < 0.5 cm2 (Smaller than Ao valve orifice area)– Small L to R shunt– Normal RV output– 75% spontaneously close < 2yrs
• Non-restrictive VSD– > 1.0 cm2 (Equal to or greater than to Ao valve
orifice area)– Equal RV and LV pressures– Large hemodynamically significant L to R shunt– Rarely close spontaneously
Based on size 1. Size 1) Large : 2/3rd of aortic annular size or > 15mm or > 1cm/sq.m of BSA Peak RV sys = LV sys pressure
2) Moderate : half of aortic annular size 5 to 15mm RV pressure to ½ of LV Qp/Os>2.0
3) Small : One third of aortic annular size insufficient size to raise RV pressure & Qp/Qs < 1.75
TYPE I VSDConal,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
Conduction system is not in surgical proximity
Doubly committed subarterial VSD
TYPE II VSDAlso 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
Danger area- inferior and posterior region of defect
Membranous VSD
TYPE III VSDAV 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
Guide- apical area of Triangle of koch
Common bundle courses around infr.
aspect of defect
Endocardial Cushion (Inlet VSD)
INLET VSD
TYPE IV VSDMuscle tissue all around the defect
May be either anterior, in the inlet septum, mid-muscular or apical
Classification according to location is important because it determines the approach for surgical closure.– Inlet and mid-muscular ----- RA
approach– Anterior ------- Rt. Ventriculotomy– Apical ------ May require left
ventriculotomy
May be Single/ multiple
Swiss Cheese VSD
MUSCULAR VSD
PathophysiologyTwo determinants– Size of defect– Pulmonary vascular resistance
These determine– Pressure gradient across VSD– Shunt volume across VSD
After birth PVR falls ------ Large flow across shunt if large VSD
Causes increased PA pressure (initially flow related), increased PV return, hence LA enlargement and LV overload
PH initially flow related and reversible
PathophysiologyLater ----- Intimal proliferation and medial hypertrophy leads to fixed irreversible PHFlow through the lungs decreases as PVR increases, hence shunt volume decreasesEventually PVR > SVR, hence R L shunt across VSD Cyanosis Eisenmengerised VSD
Shunt calculated by Fick’s principle Qp/QsAortic O2 % sat - Central Venous O2 % sat
Pulm. Vein O2 % sat – Pulm. Art O2 % sat
With small VSDs, there is resistance to flow across the VSD hence Qp/Qs is rarely > 1.5
With moderate VSDs, Qp/Qs is between 1.5 and 2.5, and is less likely to cause pulm vasc disease
VUENTURI EFFECT
HEATH- EDWARD CLASSIFICATIONGrade I - hypertrophy of the media of small muscular arteries and arterioles.
Grade II - intimal cellular proliferation in addition to medial hypertrophy.
Grade III - progressive intimal proliferation and concentric fibrosis.
Grade IV - "plexiform lesions"
Grade V - angiomatous and cavernous lesions and hyalinization of intimal fibrosis.
Grade VI - necrotizing arteritis.
Natural HistorySpontaneous closure is known, primarily with perimembranous and muscular VSDs.
Subarterial and inlet VSDs rarely close– Chances differ with age at
detectionAt 1 month 80% of large VSDs close
At 6 months 50%
At 12 months 25%
Natural History Patients with large vsd- symptom develop soon after birth.
CHF manifested by- dyspnea/rptd.pulmonary infn/hepatomegaly/sweating/failure to thrive.
Irreversible pulmonary vascular disease after 1-2 yrs of age.
Some children with isolated vsd develop Subpulmonic stenosis- pt. not at risk of pulmonary vascular disease
VSD IN ADULTSVT – AF prevalent with increasing age.
VSD+ AR – High risk of bacterial endocarditis
Right sided failure- due to pulmonary stenosis
Left sided failure- in pts. of aortic valve prolapse.
Eisenmenger complex- 2nd & 3rd decade of life
Pregnancy- spontaneous abortion/small-for-date babies
Mortality- 27% by 20 years & 69% by 60 years.
CLINICAL FEATURESGrade I
Small ventricular septal defect (less than 1.5 cm2) Patient is asymptomatic. Murmur can be present since a few days after birth.
Grade II Frequent respiratory tract infections. CHF (rare). Cyanosis is absent even during exercise.
Functional aerobic capacity is usually moderately reduced with early fatigability but unusual CHF.
Grade III More frequent respiratory tract infections. Defective growth. Moderate cyanosis at times with
exertion Congestive heart failure frequent in the first years of life (one of the most frequent causes of CHF during the first year of life). Functional capacity markedly reduced.
Grade IV or Eisenmenger Complex
EISENMENGER COMPLEX
• Infants with Eisenmenger may become easily fatigued,
especially during crying spells and at feeding time
• Low tolerance for extra exertion
• Shortness of Breath (dyspnea) and/or rapid breathing
• Fainting (syncope)
• Difficulty eating, breathing or sucking
• Poor weight gain
• Slow growth or other physical retardation
CLINICAL FINDINGS• Pulse pressure is relatively wide
• Precordium is hyperkinetic with a systolic thrill at LSB
• S1&S2 are masked by a PSM at Lt.sternal border ,max. intensity of the murmur is best heard at 3rd,4th&5th Lt interspace.Also well heard at the 2nd space but not conducted beyond apex
• Lt. 2nd space –widely split &variable accentuated P2
• Delayed diastolic murmur at the apex &S3
• Presence of mid-diastolic ,low pitched rumble at the apex is caused by increased flow across the mitral valve &indicates Qp:Qs=2:1/greater
• Maladie de Roger –small VSD presenting in older children as a loud PSM w/o other significant hemodynamic changes
ECGSize of Defect Results
Small restrictive VSDs Normal tracing
Medium-sized VSDs Broad, notched P wave characteristic of left atrial overload
• Signs of LV volume overload — deep Q and tall R waves with tall T waves in leads V5 and V6
• Signs of atrial fibrillation are often present
Large VSDs Right ventricular hypertrophy with right-axis deviation.With further progression, the ECG shows biventricular hypertrophy; P waves may be notched or peaked.
ECG CHEST X-RAYMay show right/left or combined ventricular hypertrophy
Presence of RAD represents elevated RVP and PAP
Postoperative RBBB is common
Cardiomegaly : proportional to the volume overload.
Mainly LV, LA and RV enlargement.Increased pulmonary blood flow, PAH.
Unless LA is significantly enlarged its difficult to differentiate from ASD.
RV may not be as enlarged as anticipated as it receives the shunt into its outflow tract.
KATZ WATCHTEL SIGN
42-year-old woman with Eisenmenger complex, demonstrating atrial fibrillation withright axis deviation, right ventricular hypertrophy, right bundle-branch block, and premature
ventricular beat.
Ventricular septal defect in a 7-month-old.Frontal(A)and lateral (B) views of the chest show moderate cardiac enlargement including right atrial, right ventricular, and left atrial enlargement with posterior displacement of the left main stem bronchus (arrow in B) and increased pulmonary vascularity
2D -ECHODetermine vsd location
LV outflow morphology
Aortic valve involvement
AV valve chordal attachment
Septal trabeculations may cause multiple reflections and obscure small defects
Prominent bulging of tissue into the RV : aneurysmal perimembranous VSD
2D-ECHO
Supracristal VSD, with pulm outflow tract obstruction
Cardiac catheterization
Identification of Multiple VSDs
Cardiac catheterization can quantify shunt volume and pulmonary arterial resistance. Step-up in oxygen saturation may be detected in the pulmonary artery rather than in the right ventricular cavity because of streaming of the shunted blood into the pulmonic trunk.
If aortic valve prolapse is significant, left-to-right shunting by oximetry may be fairly unremarkable, because the ventricular septal defect (VSD) in such cases is partially obstructed.
CATH GRADING
Grade I
Right atrium and right ventricular pressures are normal, due to the low volume shunt. Oxymetry can be misleading, showing only a mild step up in oxygen saturation at ventricular level. The passage to the left ventricle with the catheter is often possible.
Grade II
Elevation of right ventricular pressure and pulmonary hyperdynamics hypertension (moderate) due to large pulmonary flow. Blood oxygen measurements will show typical right ventricular oxygen step up.
If the defect is located over the Crista Supraventricularis the step up can only be seen at the pulmonary artery level. (The maximal normal step up between vena cava and atrium is 2 Vol % and between RV and MPA 0.5 Vol %; any difference over such figures must be considered abnormal.) .
Grade III
The pressure tends to equalize between right and left ventricles but with a still predominant left to right shunt. Significant blood oxygen step up is noted. With exertion, the normal peripheral arterial oxygen saturation is reduced. Significant pulmonary hypertension exists (close to systemic). There is marked R.V.H.
Grade IV: Eisenmenger Complex
Angiocardiography
Contrast injected into LV will localise the site & size of the defectContrast into the pulmonary artery will demonstrate the L-R shunt.Gerbode defect : RA opacifies from the LV injection
perimembranous ventricular septal defects
Selective left ventricular angiogram in right anterior oblique view showing a bulge (arrowheads) of the outlet septum with a subpulmonary ventricular septal defect (arrow).
Pierli C et al. Heart 2001;86:e6-e6
Copyright © BMJ Publishing Group Ltd & British Cardiovascular Society. All rights reserved.
CT MRI
APICAL MUSCULAR VSD
Flow jet (*) across the defect into the right ventricle, indicating a left-to-right shunt.
TREATMENT PROTOCOL SMALL VSD - No medication or surgery if asymptomatic– 75-80% close by 2 years . Observation
MODERATE / LARGE VSD - Treatment of CHF
Determining when to repair
INTERVENTION
Decompensated CHF
Compensated CHF with:– Large hemodynamically significant VSD - L to R shunting
with Qp/Qs > 2:1, even if asymptomatic, ideally before 1 year
– Growth failure, unresponsive to medical therapy is an indication for surgery
Surgical correction has to be done before irreversible damage to pulmonary vasculature occurs.
Indications for intervention
Significant VSD: symptomatic without irreversible pulmonary HTN * Qp/Qs > 1.5 * PA systolic pressure > 50 mm Hg * Increased LV and LA size * Deteriorating LV function
Perimembranous VSD with more than mild AR + recurrent endocarditis.
Subarterial VSD - High incidence of aortic valve prolapse/ AI
Children without irreversible pulmonary HTN * significant symptoms failing to respond to medication * elective surgery (performed between 3 ~ 9 m/o)Pulmonary HTN * PA resistance < 7 Wood units * Net left-to-right shunt of at least 1.5 * Irreversible
SURGICAL CONSIDERATION Preoperative VSD location
Avoidance of injury to conduction pathways.
Operative technique needed to secure the closure
5 operative approaches - RIGHT ATRIAL
TRANSPULMONARY
TRANSAORTIC
RIGHT VENTRICULAR
LEFT VENTRICULAR
RIGHT ATRIAL APPROACH Most frequently used
Used for – Paramembranous/ Inlet /Muscular/LV & RA types
APICAL & SWISS Cheese defect – limited left apical ventricular incision may be required
Shallow Stitching Close to the Rim of the Ventricular Septal Defect Eliminates Injury to the Right Bundle Branch
VSD
TRANSPULMONARY ARTERY Used for repair of Conal ( Supracristal vsd)
Conal Vsd – importance of patch closure
Treacherous situation- Prolapsed aortic valve leaflet may partially occlude the defect.
Avoiding injury to Aortic valve leaflet .
Repairing superior aspect of VSD
Combined approach for AI
TRANSAORTIC APPROACH Need for concomitant correction – aortic valvuloplasty / valvar or subvalvar stenosis.
Incision- curved incision over Aortic valve commisure
Absence of superior muscular or fibrous rim of the defect.
Used for DORV with subaortic VSD
RV APPROACH 2 types- TRANSVERSE/ VERTICAL
Important to examine epicardial coronary artery distribution
Indications-
- inaccesibility from rt .atrium /pulmonary artery
- defect extending into infundibular septum
- presence of obstructive infundibular muscle bundles
- difficulty exposing inferior margin of conal defect
Patch closure by
RV approach
Apical Muscular VSD Patch Closure via RVtomy
(A) Trabeculations overlying the VSD are taken down.
(B) Interrupted pledgetted sutures are placed full thickness at the superior margin of the defect, maintaining the pledgets on the left ventricular side
(C) Closure of the VSD with a Dacron patch
LV APPROACHRarely used
Vertical / Transverse incision
Limited to certain type of trabecular VSDs- multiple apical,swiss cheese
Easier to patch from LV side because of smooth septum
LV incision avoided to prevent long term ventricular dysfunction.
Interventional OptionsPercutaneous Device Closure– Muscular VSDs can typically be closed
percutaneously
Flap Valve Double Patch Closure
• Flap valve double patch closure of Ventricular Septal Defects in children with Increased Pulmonary Vascular Resistance
Much more to come
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