VENTRICULAR SEPTAL DEFECT

by

Dr.Amarnath BRBMC

CONGENITAL CONGENITAL HEART DISEASE HEART DISEASE

(con-together,genitus-born)(con-together,genitus-born)

The majority of congenital anomalies of the heart are

present 6wks after conception & most

anomalies compatible with 6mths of intrauterine life permit live offspring at

term.

TYPES OF CHDTYPES OF CHD

•Gr 1 Lt to Rt shunts

•Gr 2 Rt to Lt shunts

•Gr 3 Obsructive lesions

LEFT to RIGHT shuntsLEFT to RIGHT shunts(acyanotic heart disease)(acyanotic heart disease)

Frequent chest infections (6-8 attacks first year of life)

Tendency for increased sweating with related their tendency for developing CCF

Precordial bulge Hyperkinetic precordium Tricuspid /mitral DDM X-ray plethoric +cardiomegaly VSD,ASD, PDA,AVcanal

RIGHT to LEFT shuntsRIGHT to LEFT shunts (cyanotic heart disease)(cyanotic heart disease)

increased pulm. blood flow * mildly cyanotic * increased sweating * CCF * FTT * plethoric lung fields * cardiomegaly *TGA,singlventricle,

TA,total anomalous pulm. Return w/o obstruction

decreased pulm.blood flow

* mod. to severe cyanosis * ESM, delayed and

diminished P2 (PS) * in PH ,accentuated &

palpable P2,ESM * oligemic lung fields * TOF,PA,TA,total

anomalous pulm. return w/ obstruction

Obstructive lesionsObstructive lesions

• absence of frequent chest infections• absense of cyanosis

•

• absence of precordial bulge

• presence of forcible &heaving cardiac impulse

• systolic thrill +ESM & delayed corresponding S2

•ECG shows obstructive lesions

•X-ray normal sized heart & pulm. Vasculature

•pulm.stenosis(rt side) & aortic stenosis,coarctation of aorta(lt side)

NADA’S CRITERIANADA’S CRITERIA

MAJORMAJOR• systolic murmur gr III

or more• diastolic murmur• cyanosis• ccf

one major &two minor are essential

MINORMINOR • systolic murmur less

than gr III• abnormal S2• abnormal ECG• abnormal X-ray• abnormal BP

VENTRICULAR SEPTAL VENTRICULAR SEPTAL DEFECTDEFECT

• most common ACHD

• 2nd most common CHD(32%)

• SYNONYMS

* Roger’s disease

* Interventricular septal defect

* congenital cardiac anomaly

PATHOPHYSIOLOGYPATHOPHYSIOLOGY primarily depends on size&status of pulm. vascular bed rather than

location Small communication (less than 0.5cm`) VSD is restrictive &

rt.ventricular pressure is normal – does not cause significant hemodynamic derangement(Qp:Qs=1.75:1.0)

Moderately restrictive VSD with a moderate shunt(Qp:Qs=1.5-2.5:1.0) &poses hemodynamic burden on LV

Large nonrestrictive VSDs(more than 1.0cm`) Rt&Lt ventricular pressure are equalised(Qp:Qs is more than 2:1)

Large VSDs at birth ,PVR may remain higher than normal and Lt to Rt shunt may intially limited – involution of media of small pulm.arterioles,PVR decreases—large Lt to Rt shunt ensues

In some infants large VSDs ,pulm. arteriolar thickness never decreases –pulm.obstructive disease develops .when Qp:Qs=1:1 shunt becomes bidirectional,signs of heart failure abate &pt. becomes cyanotic. (Eisenmenger syndrome)

ANATOMICALANATOMICALCLASSIFICATIONCLASSIFICATION

typeI-MEMBRANOUS SEPTUMMEMBRANOUS SEPTUM paramembranous/perimembranous defect (or infracristal,subaortic,conoventricular)typeII-MUSCULAR SEPTUMMUSCULAR SEPTUM inlet,trabecular,central,apical,marginal or swiss-cheesetypeIII-OUTLET SEPTUMOUTLET SEPTUM deficient supracristal,subpulmonary,infundibular or

conoseptalSEPTAL DEFICIFNCYSEPTAL DEFICIFNCY –AVseptal defect (AVcanal)

CLINICAL FEATURESCLINICAL FEATURES

Race : no particular racial predilection Sex :no particular sex preference Age :infantsinfants– difficult in postnatal period,although ccf

during first 6mths is frequent,X-ray&ECG are normal. childrenchildren—after first year variable clinical picture

emerges.small VSD – asymptomatic large VSD – common symptoms -palpitation,dyspnoea on exertion,feeding

difficulties ,poor growth -frequent chest infections

PHYSICAL FINDINGSPHYSICAL 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 RogerMaladie de Roger –small VSD presenting in older children as a loud PSM w/o other significant hemodynamic changes

INVESTIGATIONSINVESTIGATIONS ECHOCARDIOGRAPHYECHOCARDIOGRAPHY two-dimensional &doppler colour flow

• CHEST RADIOGRAPHYCHEST RADIOGRAPHY - normal - biventricular hypertrophy - pulmonary plethora

• ELECTROCARDIOGRAPHYELECTROCARDIOGRAPHY -smallVSD ~ normal tracing -mod.VSD ~ broad,notched P wave characteristic of Lt. Atrial

overload as well as LV overload,namely,deep Q waves & tall R waves in leads V5 and V6 and often AF

-large VSD ~RVH with rt. axis deviation. With further progression biventricular hypertrophy;P waves may be notched/peaked.

Other investigationsOther investigations

CAT SCAN

(Computed Axial Tomography)

• MRI

• ULTRASOUND

• ANGIOGRAPHY

(cardiac catheterization and angiography)

COMPLICATIONSCOMPLICATIONS

Congestive cardiac failure Infective endocarditis on rt.ventricular side Aortic insufficiency Complete heart block Delayed growth & development (FTT) in infancy Damage to electrical conduction system during

surgery(causing arrythmias) Pulmonary hypertension

INTERVENTIONINTERVENTION

3 MAJOR TYPES SMALL (less than 3mm SMALL (less than 3mm

diameter)diameter) - hemodynamically

insignificant - b/w 80-85% of all VSDs - all close spontaneously * 50% by 2yrs * 90% by 6yrs * 10% during school yrs

- muscular close sooner than membranous

MODERATE VSDsMODERATE VSDs * 3-5mm diameter * least common group of children(3-5%) * w/o evidence of ccf/ pulm.htn can be

followed until spontaneous closure occurs.• LARGE VSDs WITH NORMAL PVRLARGE VSDs WITH NORMAL PVR * 6-10mm in diameter * usually requires surgery otherwise… develop CCF & FTT by age of 3-6mths.Conservative treatment - treat CCF & prevent development of

pulm.vascular disease - prevention & treatment of infective

endocarditis

INDICATIONS for SURGERYINDICATIONS for SURGERY VSDs at any age where clinical symptoms and

FTT cannot be controlled medically. Infants b/w 6-12mths of age with large defects

ass. with PH ,even if symptoms are controlled by medication.

Pt.s older than 24mths of age with Qp:Qs is greater than 2:1.

Pt.s with supracristal VSD of any size, because of high risk of development of AI.

CONTRAINDICATIONCONTRAINDICATION –severe pulmonary vascular disease.

Surgical correction has to be done before irreversible damage to pulmonary vasculature occurs.

Operative procedureOperative procedure Usually performed in second year.If symptoms

are not disabling ,procedure may be deffered to 4-6yrs.

Through a median sternotomy with the help of extracorporeal circulation,a longitudinal ventriculotomy is performed usually in the infundibular part of the rt.ventricle & near the ant.descending coronary artery.

Alternate approach is through the rt.atrium, particularly when PVR is increased .

Defect is usually closed with an oval patch of knitted dacron by mattress suture posteriorly and continous suture anteriorly using prolene.

Much more to comeMuch more to come

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