Ventricular Septal Defect (VSDs)
VSD is an abnormal communication between right and left ventricles.
Types of ventricular septal defect
1. Membranous ventricular septal defect
Located beneath aortic valve, most common.
2. Subpulmonic ventricular septal defect
Located beneath pulmonary valve
3. Atrioventricular canal type ventriculoseptal defects or posterior defects
Large hole located where wall (septum) between upper chamber (atria joints wall between lower chamber (ventricle).
4. Muscular ventricular septal Defects
Hole in wall (septum) that separated lower chamber (ventricle).
5. Inlet
Hole below right tricuspid and mitral valve in left ventricle.
6. Outlet
Hole just before pulmonary valve in right ventricle and just before aortic valve in left ventricle.
Pathophysiology of Ventricular Septal Defects
In presence of Ventricular septal defect
Portion of oxygenated blood returning from into left atrium and left ventricle cross ventricular septal defect
Enter blood right ventricle, from where it return to pulmonary circulation.
Shunt is left to right
Shunt is determined by size of ventricular septal defect and amount pulmonary vascular resistance (PVR) present.
High pulmonary vascular resistance will elevate right ventricular pressure and decrease shunting across VSD.
In newborn, PVR is high (little shunting), child may asymptomatic.
Due to increase increase blood in right ventricle, right ventricular hypertrophy occurs.
Clinical features
VSD depend upon size of defect, degree of shunting, age of child and pulmonary vascular resistance.
1. Small VSD
Little shunting, child asymptomatic
2. Large VSD
Left to right shunt occurs, infants / child failure to thrive and congestive heart failure.
3. Medium size VSD
Produce symptoms dysnea, tachypnea, slow physical development, feeding difficulties and frequent pulmonary infections.
Diagnostic evaluation
1. Cardiac Examination
Blood flow cross VSD
Produce systolic murmur
In presence of large VSD - Left to right shunt, increase regurgitation of blood across mitral valve produce diastolic murmur.
2. Electrocardiogram
Presence of small VSD - ECG normal
Moderate to large VSD- right ventricular hypertrophy
3. Chest radiograph
With moderate to large size VSD.
Heart size and pulmonary vascular marking
4. Echocardiogram
Colour 2D echocardiography
Determining of size and location of ventricular septal defect
Degree of left to right shunting and PVR also assessed.
Therapeutic Management
1. Small VSD- close spontaneously
2. Infant with small VSD - No surgery, administer antibiotics to prevent endocarditis.
3. Infant moderate to large VSD
Who symptomatic - Congestive heart failure, failure to thrive
medically managed
Digoxin and diuretics combination
If infant continue show sign of CHF - need surgical repair
Surgical repair VSD, Open heart procedure
1. Cardiopulmonary bypass surgery
2. Moderate to small size VSD
Closed by purse string suture
3. Large VSD
Synthetic Dacron patch used to close defect.
Cardiac tissue covers patch with 6 months of surgery.
4. Median sternotomy - large VSD
5. Antibiotic prophylaxis for endocarditis
Post Operative Complication
1. Residual ventricular septal defect
2. Conduction abnormalities
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