The murmur in patent ductus arteriosus is characterized as being
systolic and diastolic with a crescendo and decrescendo pattern, peaking
at around the closure of the aortic valve (A2). Due to the
left-to-right shunting at the patent ductus arteriosus the pulmonary
venous return will be increased causing dilatation of the left atrium and
stretching of the patent foramen ovale with more left-to-right shunting at
the atrial level worsening congestive heart failure. The patent ductus
arteriosus murmur is best heard over the second left intercostal space.
Clicking noises during the murmur gives the characteristic machinery
quality of the patent ductus arteriosus murmur.
Murmurs mimicking patent ductus arteriosus include AP window, venous
hum, ruptured sinus of Valsalva (aorta to RA, RV or LA shunts), coronary
artery to ventricular cavity fistula and tetralogy of Fallot with
pulmonary atresia and large collaterals.
Patients present with congestive heart failure, this include easy
fatigability (poor feeding in infants), shortness of breath, pallor
sweating and cool extremities with exertion. Signs include bounding
pulses, increase left ventricular apical impulse, thrill, continuous
murmur and pulmonary sounds consistent with pulmonary edema such as rales