Ventricular Septal Defect
Introduction
Congenital anomalies of the heart and blood vessels arise during the 1st 10 wk of embryonic development
Present at birth.
The incidence is 1/120 live births;
Estimated risk is 2 to 3% in children with an affected 1st-degree relative.
Aetiology
About 5% of patients have a chromosomal abnormality (eg, trisomy 13, 18, or 21, Turner's syndrome);
May be part of a genetic syndrome (eg, Holt-Oram syndrome).
Maternal illnesses (eg, diabetes mellitus, SLE, rubella),
Environmental exposure (eg, to thalidomide)
Usually, no specific cause is identified.
The anomalies
Ventricular Septal Defect
A defect in the ventricular septum.
The ventricular septum consists of an inferior muscular and superior membranous portion
The membranous portion, which is close to the atrioventricular node, is most commonly affected in adults and older children.
The most common congenital heart defect
Holo- or pansystolic murmur.
VSD may be silent.
Investigations
Echocardiography.
Cardiac catheterization.
Pathophysiology
During ventricular contraction, or systole, some of the blood from the left ventricle leaks into the right ventricle, passes through the lungs and reenters the left ventricle via the pulmonary veins and left atrium. This has two net effects. First, the circuitous refluxing of blood causes volume overload on the left ventricle. Second, because the left ventricle normally has a much higher systolic pressure (~120 mm Hg) than the right ventricle (~20 mm Hg), the leakage of blood into the right ventricle elevates right ventricular pressure and volume, causing pulmonary hypertension with its associated symptoms. This effect is more noticeable in patients with larger defects, who may present with breathlessness, poor feeding and failure to thrive in infancy. Patients with smaller defects may be asymptomatic.
Signs and symptoms
Ventricular septal defect is usually symptomless at birth. It usually manifests a few weeks after birth.
VSD is an acyanotic congenital heart defect
There is a Left-to-right shunt, so there are no signs of cyanosis.
Pansystolic / Holosystolic murmur (depending upon the size of the defect)
Treatment
Conservative or surgical.
Smaller congenital VSDs often close on their own, as the heart grows
Percutaneous endovascular procedures are less invasive and can be done on a beating heart
Repair of most VSDs is complicated by the fact that the conducting system of the heart is in the immediate vicinity.
Ventricular septum defect in infants is initially treated medically with cardiac glycosides (e.g., digoxin), loop diuretics (e.g., furosemide) and ACE inhibitors (e.g., captopril)
other anomalies
Ventricular Septal Defect Atrial Septal Defect Tetralogy of Fallot Ebstein Anomaly Eisenmenger Syndrome Endocardial Cushion Defects Lutembacher Syndrome Patent Ductus Arteriosus Aortic Coarctation Transposition of great vessels
