Patent Ductus Arteriosus
Definition
Persistent patency of the fetal vessel that Connects the pulmonary artery with the aorta
Etiology
- Prematurity
- Maternal rubella
- High altitude
Physiology
- Closure begins within a few hours of birth and is completely sealed within two to three weeks
Shunt
- Left-to-right
Cardiac Auscultation
- Continuous murmur, best heard in the pulmonic area
Electrocardiogram
- Left atrial enlargement
- Left ventricular enlargement
Chest X-ray
- May be normal
- Pulmonary congestion
- Calcification of the ductus
- May have prominence of pulmonary arteries and veins
- May have prominence of main pulmonary artery
Cardiac Catheterization
- May detect oxygen step-up in pulmonary artery from right ventricle
Treatment
- Surgical ligation
- Indomethacin
- Coil / device closure
M-Mode
- Limited
- Left atrial enlargement
- Left ventricular enlargement
- Left ventricular volume overload pattern (left ventricular enlargement with hyperkinetic wall motion)
- LA/Ao ratio"> 1.4:1
2-D
- Parasternal short-axis may provide direct visualization
Doppler
- Parasternal short-axis of the aortic valve is the best view
- PW and color flow Doppler demonstrate a left-to-right shunt
- Determine Qp/Qs
- Determine systolic pulmonary artery pressure