What is the management approach for a patient presenting with a ventricular septal defect (VSD) murmur?

Management of Ventricular Septal Defect Murmur

The management approach for a patient with a ventricular septal defect (VSD) murmur should be based on the size of the defect, presence of symptoms, and hemodynamic significance, with surgical closure indicated for symptomatic patients with moderate to large VSDs causing left ventricular volume overload. 1, 2

Diagnostic Evaluation

Physical Examination

• A VSD typically presents with a holosystolic murmur over the third to fourth intercostal space, often with a palpable thrill 1
• In small VSDs, the physical examination may be normal except for the murmur 1
• In large VSDs with pulmonary hypertension, the murmur may be limited to early and midsystole 1
• Patients with severe pulmonary arterial hypertension (PAH) may have no murmur, a single loud second heart sound, and cyanosis/clubbing 1

Imaging Studies

• Echocardiography is the primary diagnostic tool, providing information on: 1, 3

  • Location, number, and size of the defect
  • Severity of left ventricular volume overload
  • Estimated pulmonary artery pressure
  • Presence of aortic valve prolapse or regurgitation
  • Assessment of ventricular function

• Chest X-ray findings depend on defect size: 1

  • Small VSD: normal chest X-ray
  • Significant left-to-right shunt: left atrial and LV enlargement with increased pulmonary vascular markings
  • PAH: prominent pulmonary artery segment with pruning of distal pulmonary vessels

• MRI or CT may be useful when: 1

  • Associated lesions are suspected
  • Echocardiographic windows are suboptimal
  • Three-dimensional anatomy assessment is needed

Hemodynamic Assessment

• Cardiac catheterization is reasonable to assess PAH and test vasoreactivity in patients with repaired or unrepaired VSD 1
• Exercise testing may be used to objectively assess functional capacity 1

Management Approach

Indications for Intervention

Surgical or catheter-based closure is indicated in the following situations: 1

• Patients with symptoms attributable to left-to-right shunting through the VSD who don't have severe pulmonary vascular disease
• Asymptomatic patients with evidence of LV volume overload
• Patients with a history of infective endocarditis
• Patients with VSD-associated prolapse of an aortic valve cusp causing progressive aortic regurgitation
• Patients with VSD and PAH when there is still net left-to-right shunt (Qp:Qs >1.5) and PAP or PVR are <2/3 of systemic values

Medical Management

• Most patients with small VSDs need no regular medication 1
• For patients with symptoms of heart failure: 1
  • ACE inhibitors for AV valve regurgitation and symptoms of chronic heart failure
  • Diuretics (furosemide) for volume management
  • In infants with significant symptoms, furosemide (<2 mg/kg/day orally) with spironolactone added at higher doses to prevent potassium loss 4

Surgical Management

• Surgical closure is advised for: 2

  • Perimembranous VSDs
  • Supracristal VSDs
  • Inlet VSDs
  • VSDs involving prolapsed aortic valve leaflets

• For post-myocardial infarction VSDs: 5

  • Urgent surgical intervention is required for survival
  • Initial stabilization with vasodilators (IV nitroglycerin) and intra-aortic balloon counterpulsation
  • Pre-operative coronary angiography should be performed
  • Hospital mortality after surgery ranges from 25% to 60%

Catheter-Based Interventions

• Percutaneous closure with devices is preferred for many patients with muscular VSDs 2, 6
• Hybrid procedures (combining surgical and catheter techniques) may be used for some complex defects 6
• Percutaneous closure of perimembranous VSDs carries a risk of complete heart block and is not widely recommended 2

Follow-up Recommendations

• Regular echocardiographic assessment to monitor: 1

  • Development of aortic or tricuspid regurgitation
  • Degree of residual shunt
  • Left ventricular function
  • Pulmonary artery pressure
  • Development of double-chambered right ventricle
  • Development of discrete subaortic stenosis

• Patients with LV dysfunction, residual shunt, PAH, aortic regurgitation, or outflow tract obstruction should be seen annually at specialized centers 1

• Monitor for development of complete AV block, especially in patients who developed bifascicular or transient trifascicular block after VSD closure 1

Pitfalls and Caveats

• Small VSDs may be misdiagnosed as innocent murmurs 1
• Residual VSDs detected intraoperatively are common but most are trivial and resolve spontaneously 7
• Surgery should be avoided in Eisenmenger VSD and when exercise-induced desaturation is present 1
• Avoid unnecessary procedures for small defects that don't cause symptoms or hemodynamic compromise 2
• Heart failure in infants with VSDs may be misdiagnosed as pneumonia 4
• Development of complications such as aortic valve prolapse, double-chambered right ventricle, or subaortic stenosis requires vigilant monitoring 1, 4