What is the management approach for patients with Atrial Septal Defect (ASD) and Patent Ductus Arteriosus (PDA)?

Management of Atrial Septal Defect (ASD) and Patent Ductus Arteriosus (PDA)

For patients with both ASD and PDA, device closure is the preferred management approach, with PDA closure recommended first, followed by assessment of the ASD which may decrease in size or close spontaneously after PDA closure.

Diagnostic Evaluation

Initial Assessment

• Detailed history focusing on:
  • Symptoms of heart failure (respiratory distress, feeding difficulties, diaphoresis)
  • Exercise intolerance
  • Growth patterns
  • Presence of cyanosis (especially differential cyanosis in PDA)

Physical Examination

• Vital signs with blood pressure in all four extremities (to detect differential hypertension in PDA)
• Oxygen saturation in both hands and feet (to assess for right-to-left shunting) 1
• Precordial impulse and thrills
• Heart sounds (continuous machinery murmur of PDA, systolic murmur of ASD)
• Femoral pulses (bounding in significant PDA)

Diagnostic Testing

• ECG: May show right atrial enlargement, RV hypertrophy, LV hypertrophy depending on shunt size 2
• Chest X-ray: Cardiomegaly, increased pulmonary vascular markings, prominent pulmonary artery
• Echocardiography: Key diagnostic tool to evaluate 2:
  • Size and location of defects
  • Direction and magnitude of shunting (Qp:Qs ratio)
  • Chamber enlargement
  • Pulmonary artery pressure
  • Ventricular function
• Cardiac catheterization: Indicated when pulmonary hypertension is suspected 2

Management Algorithm

Step 1: Assess Hemodynamic Significance

Determine if intervention is needed based on:

• Presence of symptoms
• Evidence of right heart volume overload
• Qp:Qs ratio ≥1.5:1
• Pulmonary artery pressure

Step 2: Evaluate for Pulmonary Hypertension

• Measure pulmonary artery systolic pressure (PASP)
• Calculate pulmonary vascular resistance (PVR)

Step 3: Determine Management Strategy Based on Hemodynamics

For PDA:

1. Closure indicated (Class I) 2:

   • Left atrial/LV enlargement with net left-to-right shunt
   • PASP <50% systemic and PVR <1/3 systemic

2. Closure may be considered (Class IIb) 2:

   • Net left-to-right shunt
   • PASP ≥50% systemic and/or PVR >1/3 but <2/3 systemic

3. Closure contraindicated (Class III: Harm) 2:

   • Net right-to-left shunt
   • PASP >2/3 systemic or PVR >2/3 systemic

For ASD:

1. Closure indicated (Class I) 2:

   • Right atrial and RV enlargement
   • Qp:Qs ≥1.5:1
   • PASP <50% systemic and PVR <1/3 systemic

2. Closure may be considered (Class IIb) 2:

   • Net left-to-right shunt (Qp:Qs ≥1.5:1)
   • PASP ≥50% systemic or PVR >1/3 but <2/3 systemic

3. Closure contraindicated (Class III: Harm) 2:

   • PASP >2/3 systemic
   • PVR >2/3 systemic
   • Net right-to-left shunt

Step 4: Intervention Approach for Combined ASD and PDA

When both defects require closure, close the PDA first, then reassess the ASD 3, 4:

1. PDA closure may lead to reduction in ASD size or spontaneous closure in some cases
2. Small to moderate ASDs have significant probability to decrease in size after PDA closure 3
3. If ASD remains hemodynamically significant after PDA closure, proceed with ASD closure

Intervention Methods

For PDA:

• Transcatheter device closure: Preferred method for most PDAs 2
  • Consider device selection based on PDA size and morphology
  • Consult with ACHD interventional cardiologists before selecting surgical approach 2

For ASD:

• Transcatheter device closure: For secundum ASDs with appropriate anatomy 2
• Surgical repair: For primum ASDs, sinus venosus defects, or when device closure not feasible 2

Special Considerations

Calcified PDA in Adults

• Device closure should be first option due to increased surgical risk from calcification 2
• Surgical approach may be necessary if PDA is too large for device closure or has distorted anatomy 2

Combined Procedures

• Combined transcatheter closure of both defects can be performed safely when indicated 4, 5
• Success rates for device closure exceed 97% for both ASD and PDA 5

Eisenmenger Physiology

• Never close defects in patients with Eisenmenger physiology 2
• Management focuses on pulmonary vasodilator therapy and supportive care 1

Follow-up Protocol

1. Post-procedure follow-up:

   • Echocardiography at 24 hours, 3-6 months, and yearly thereafter 1
   • Monitor for residual shunts, device complications, and arrhythmias

2. Long-term follow-up:

   • Patients with small PDAs without left heart volume overload: Every 3-5 years 2
   • Patients with device closure: Every 5 years due to limited long-term data 2
   • Patients with complete surgical closure and no residual abnormalities: Can be discharged from follow-up once complete closure is documented 2

Clinical Pearls and Pitfalls

• In adults, calcified PDA poses higher surgical risk; catheter intervention should be first option 2
• When both defects are present, closing PDA first may lead to spontaneous reduction or closure of ASD 3
• Avoid closure in patients with severe pulmonary hypertension and right-to-left shunting as this can precipitate right heart failure 2, 1
• Differential cyanosis (lower extremities more cyanotic than upper) suggests right-to-left shunting through PDA 2