Patent Ductus Arteriosus


-Embryonic ductus arteriosus allows shunting of blood from the PA to the aorta, bypassing the lungs 

-It normally closes immediately after birth 

-Failure to close results in left-to-right shunt 

-Risk factors: Down syndrome, rubella, 

Symptoms & signs 

-Usually asymptomatic at birth and during childhood 

-No symptoms in mild cases 

-Shortness of breath, sweating, almost always acyanotic but differential cyanosis can happen; lower extremities and sometimes the left hand show clubbing and cyanosis, but the right hand and head are always pink

-Continuous ‘machinery’  ‘to-and-fro’ murmur loudest over left pulmonary area below the left clavicle, widened pulse pressure, loud S2, accentuated in late systole at the time of S2, S2 is obliterated by the waxing and waning of the murmur 

Complications: Left heart dilation, pulmonary hypertension, Eisenmenger syndrome, heart failure, infective endocarditis 


Chest X-ray: normal 

ECG: normal or left atrial and ventricular hypertrophy 

Echocardiogram: left atrial and ventricular enlargement 


-Prior to birth, circulating prostaglandins keep the ductus patent, so a PDA can be closed by administering a prostaglandin inhibitor like indomethacin 

 Indomethacin is ineffective in term infants with PDA 

-Surgical ligation 

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