Management of Perimuscular Ventricular Septal Defect
Primary Management Decision
Small restrictive perimuscular VSDs (Qp:Qs <1.5:1) with normal pulmonary pressures should be managed conservatively with surveillance, as they demonstrate excellent long-term outcomes with 96% survival at 25 years without intervention. 1
Indications for Closure
Closure is indicated when:
Hemodynamically significant left-to-right shunt (Qp:Qs ≥1.5:1) with left ventricular volume overload is present, provided pulmonary artery systolic pressure remains <50% of systemic pressure and pulmonary vascular resistance is <1/3 systemic resistance 1, 2
Symptomatic heart failure develops attributable to left-to-right shunting without severe pulmonary vascular disease 2, 3
Progressive aortic regurgitation develops from VSD-associated aortic valve prolapse (particularly relevant for perimembranous defects, which can occur in 6% of cases) 1, 3
Treatment Modality Selection
Catheter-Based Closure
Transcatheter device occlusion is specifically recommended for muscular VSDs and represents the preferred approach for these defects. 1, 2 This distinguishes muscular VSDs from perimembranous VSDs where surgical closure remains preferred due to 1-5% risk of complete heart block with device closure 4, 5
- The Amplatzer Muscular VSD Occluder demonstrates good safety and efficacy profile 1, 5
- Percutaneous closure offers excellent results with low morbidity and mortality without cardiopulmonary bypass 4, 6
Hybrid Perventricular Approach
For large mid-muscular VSDs in infants, or defects located apically/anteriorly that are difficult to identify surgically, perventricular hybrid closure should be considered as the preferred therapeutic modality. 4, 7
- This approach is particularly valuable for neonates with concomitant lesions (e.g., aortic coarctation) 7
- Performed via sternotomy or subxyphoid approach under transesophageal echocardiography guidance 7
- Cardiopulmonary bypass needed only for repair of concomitant lesions 7
Surgical Closure
Surgical closure remains an option but is generally reserved for cases where catheter-based approaches are not feasible or when concomitant cardiac lesions require surgical correction 4, 6
Medical Management
For patients not meeting closure criteria or awaiting intervention:
- ACE inhibitors for chronic heart failure symptoms 2, 3
- Diuretics (furosemide) for volume management and pulmonary congestion 2, 3
- Nitrates for symptom relief in patients without hypotension 2, 3
Absolute Contraindications to Closure
VSD closure must NOT be performed in:
- Eisenmenger syndrome with PA systolic pressure >2/3 systemic, pulmonary vascular resistance >2/3 systemic, and/or net right-to-left shunt 1, 2, 3
- Exercise-induced desaturation indicating severe pulmonary vascular disease 3
The mortality risk with closure in these patients is unacceptably high and the practice should be strongly avoided 1
Follow-Up Protocol
Annual Follow-Up Required For:
- Residual heart failure 1, 2, 3
- Residual shunts 1, 3
- Pulmonary arterial hypertension 1, 2, 3
- Aortic or tricuspid regurgitation 1, 2, 3
- RV or LV outflow tract obstruction 1, 2, 3
Every 3-5 Years For:
Every 1-2 Years For:
- Device closure of VSD (depending on location and other factors) 1
Surveillance Echocardiography Should Assess:
- Development of aortic or tricuspid regurgitation 2, 3
- Left ventricular function and volume overload 2, 3
- Pulmonary artery pressure 2, 3
- Development of double-chambered right ventricle 2, 3
- Development of discrete subaortic stenosis 2, 3
Critical Pitfalls to Avoid
Common diagnostic errors:
- Mistaking small muscular VSDs for innocent murmurs – vigilant monitoring for complications is essential 2, 3
- Failure to recognize spontaneous closure potential – this is frequent in muscular VSDs and should be anticipated 2
- Proceeding with closure in patients with severe PAH – always confirm pulmonary vascular resistance is <1/3 systemic before intervention 1
Management errors:
- Delaying intervention in symptomatic patients with appropriate hemodynamics – timely closure prevents pulmonary vascular obstructive disease 5, 8
- Using percutaneous devices for perimembranous VSDs – the 1-5% heart block risk makes surgical closure preferred for these defects 4, 5
Special Considerations
Pregnancy
- Pregnancy in patients with VSD and severe PAH (Eisenmenger syndrome) is contraindicated owing to excessive maternal and fetal mortality 1
- Women with small VSDs, no PAH, and no associated lesions have no increased cardiovascular risk for pregnancy 1