Indications for intervention of ASD and VSD

ASD

Morphology 4 Types of ASD: * ostium primum * ostium secundum * sinus venosus * coronary sinus defects ↑Left to right shunt: * left ventricular compliance↓ * left atrial pressure ↑

Clinical feature Large ASD(Qp/Qs > 2): CHF, pulmonary HTN or failure to thrive Undetective ACD with a significant shunt (Qp/Qs > 1.5): symptoms ↑with aging 80% spontaneous closure occur < 1 y/o

Indications for intervention Asymptomatic children: Right heart dilation + a significant ASD (>5 mm) without spontaneous closure Significant ASD (Qp/Qs > 1.5) ASD associated with RV volume overload To prevent paradoxical emboli in stroke patients Pulmonary HTN: * Resistance < 8.0 Wood units/m2 * Net left-to-right shunt of at least 1.5 * Pulmonary artery reactive to vasodilator (e.g., O2 or NO) * Lung biopsy revealed pulmonary arterial changes are potentially reversible

Intervention Device closure * For secundum ASD with stretched diameter < 36 mm + adequate rims * Exception: 1) Anomalous pulmonary venous connection 2) Proximity to the AV valves / coronary sinus / systemic venous drainage Surgery * For sinus venosus or ostium primum defects or with secundum defects with unsuitable anatomy * primary suture closure or using a pericardial or synthetic patch

VSD

Morphology 4 components of Septum: Membranous, inlet, trabecular, outlet (conal, infundibular) part 3 Types of VSD * Muscular VSD * Membranous VSD * Doubly committed subarterial VSD (juxta-arterial/supracristal/outlet/conal defects)

Pathophysiology Shunt Qp/Qs P/A systolic pressure ratio Restrictive VSD Small 1~1.4 <0.3 Moderately restrictive VSD Moderate 1.4~2.2 0.3~0.66 Nonrestrictive VSD Large >2.2 >0.66 Eisenmenger VSD Right to left <1 1

Indications for intervention Significant VSD: symptomatic without irreversible pulmonary HTN * Qp/Qs > 1.5 * PA systolic pressure > 50 mm Hg * Increased LV and LA size * Deteriorating LV function Perimembranous VSD with more than mild AR + recurrent endocarditis. Subarterial VSD Children without irreversible pulmonary HTN * significant symptoms failing to respond to medication * elective surgery (performed between 3 ~ 9 m/o) Pulmonary HTN * PA resistance < 7 Wood units * Net left-to-right shunt of at least 1.5 * Irreversible

Intervention Surgery: direct suture or with a patch * Single-stage closure: large defect, CHF s/s, failure to thrive * Perimembranous and muscular defects + normal PAP + no s/s delayed op up to 1 year or more * Patient >10 y/o with a small defect (Qp:Qs < 1.5; normal PAP)  controversial Device closure: * Trabecular VSDs have proven more amenable * Perimembranous VSDs is technically more challenging