Ventricular Septal Defect

Physical Examination

• General examination:

  • Signs of heart failure (e.g., peripheral edema, elevated jugular venous pressure)

  • Cyanosis (in cases with right-to-left shunt)

  • Clubbing (if associated with cyanotic heart disease)

  • Evidence of underlying syndromes (e.g., Down's syndrome)

• Precordial inspection:

  • Visible apical impulse (suggestive of left ventricular enlargement)

• Palpation:

  • Thrill at left sternal edge (indicative of turbulent blood flow)

  • Displaced apex beat (left ventricular enlargement)

• Auscultation:

  • Harsh pansystolic murmur at left lower sternal edge (characteristic of VSD)

  • Second heart sound may be widely split (due to delayed pulmonary valve closure)

• Additional examination:

  • Hepatomegaly (right-sided heart failure)

  • Peripheral pulses (to rule out coarctation of the aorta)

Investigations

• Laboratory tests:

  • Complete blood count (anemia, infection)

  • Blood gas analysis (hypoxia, acidosis)

  • Cardiac biomarkers (assess for myocardial damage)

  • B-type natriuretic peptide (BNP, heart failure)

• Imaging:

  • Chest X-ray (cardiomegaly, pulmonary congestion)

  • Echocardiography (confirm diagnosis, assess shunt severity, related complications)

  • Cardiac MRI (evaluate cardiac anatomy, function)

• Invasive tests:

  • Cardiac catheterization (hemodynamic assessment, shunt quantification)

  • Electrophysiology study (if arrhythmias suspected)

Management

• General management:

  • Treat underlying conditions (e.g., infection)

  • Monitor growth and development

  • Oxygen therapy (if hypoxia)

• Medical management:

  • Diuretics (heart failure)

  • ACE inhibitors (afterload reduction)

  • Beta-blockers (symptomatic relief)

• Surgical management:

  • Percutaneous device closure (minimally invasive)

  • Surgical repair (open-heart surgery, if device closure not feasible)

• Other management:

  • Genetic counseling (for families with history of congenital heart disease)

  • Regular follow-ups (assessing growth, development, heart function)

Complications of VSD

• Heart failure:

• Pulmonary hypertension

• Reversal of shunt (Eisenmenger's syndrome)

• Infective endocarditis

• Arrhythmias

• Growth and developmental problems (in children)

Causes of VSD

Congenital causes:

• Genetic factors:

  • Chromosomal abnormalities (e.g., Down syndrome, trisomy 13, trisomy 18)

  • Single gene mutations (e.g., NKX2.5, GATA4, TBX5)

  • Familial predisposition

• Environmental factors:

  • Maternal infections during pregnancy (e.g., rubella)

  • Exposure to teratogens (e.g., retinoic acid, thalidomide)

• Multifactorial inheritance:

  • Combination of genetic and environmental factors

  • Most common cause of isolated VSDs

Acquired causes:

• Myocardial infarction:

  • Most common cause of acquired VSD

• Trauma:

  • Blunt or penetrating injury to the chest

• Infection:

  • Endocarditis causing septal perforation

  • Myocarditis weakening the interventricular septum

• Iatrogenic causes:

  • Complication of cardiac surgery or catheterization

  • Septal perforation during interventions (e.g., septal ablation for hypertrophic cardiomyopathy)

Types of VSD

• Perimembranous (infracristal): commonest 80%

• Muscular

• Infundibular (Supracristal, subarterial, subpulmonary,conal)

• AV canal/endocardial cushion type

Indications for surgery

• Pulmonary-systemic blood flow ratio (Qp:Qs) ≥ 1.5:1

• Worsening AR caused by VSD

• Recurrent IE