Anatomy vs. shunt fraction: haemodynamic consequences in atrial septal defects and partial anomalous pulmonary venous...

Area of Science:

• Cardiology
• Pediatric Cardiology
• Congenital Heart Disease

Background:

• Atrial septal defect (ASD) and partial anomalous pulmonary venous connection (PAPVC) are common noncyanotic congenital heart defects (CHD).
• These conditions create a left-to-right shunt, altering blood flow dynamics.
• Understanding the hemodynamic impact of isolated and combined defects is crucial for patient management.

Purpose of the Study:

• To evaluate the hemodynamic consequences of isolated ASD, isolated PAPVC, and combined ASD-PAPVC.
• To compare these hemodynamic profiles using cardiovascular magnetic resonance (CMR).
• To identify potential anatomical influences on the hemodynamic impact of these defects.

Main Methods:

• Retrospective analysis of 110 patients with isolated ASD, isolated PAPVC, or ASD-associated PAPVC.
• Cardiovascular magnetic resonance (CMR) imaging for geometric assessment and ventricular function evaluation.
• Quantification of pulmonary (Qp) and systemic (Qs) blood flow to determine the Qp/Qs ratio, compared against 40 healthy controls.

Main Results:

• Significant differences in right ventricular end-diastolic volumes and Qp/Qs ratios were observed across all patient groups compared to controls.
• Right ventricular volumes were significantly elevated in isolated PAPVC and ASD-associated PAPVC groups.
• No significant anatomical factors modulated cardiac geometry, ventricular function, or flow patterns between patient groups.

Conclusions:

• The hemodynamic impact of isolated ASD, isolated PAPVC, and their association is primarily determined by the magnitude of the left-to-right shunt.
• Phenotypic differences between these conditions do not appear to significantly alter cardiac geometry or function independently.
• Management strategies should focus on the degree of shunting rather than specific anatomical subtypes.