Cardiovascular Medicine - Education Center


Murmurs associated with arterio-venous (left-right) shunts:



Patent ductus arteriosus
In patent ductus arteriosus, the abnormality is a persistent embryonic vessel which connects the pulmonary artery to the aorta. The shunt is usually from left to right - from the aorta to the pulmonary artery unless pulmonary hypertension also occurs. The characteristic feature is a loud "machinery" murmur that is heard anywhere on the precordium.

Patent ductus arteriosus in wav format

Patent ductus arteriosus in real audio format

Atrial septal defect
Depending on which parts of the embryonal heart are affected in development, atrial septal defects may be divided into 2 types: ostium secundum (90%), which does not involve the atrioventricular valves and ostium primum (10%), which involves the atrioventricular valves. On auscultation, this defect does not produce any murmurs by itself but fixed splitting of S2 is definitely produced and a low-pitched diastolic tricuspid flow murmur and a pulmonary ejection systolic murmur may be produced.

Atrial septal defect in wav format

Atrial septal defect in real audio format

Ventricular septal defect
In ventricular septal defect, 1 or more holes are present in the membranous or muscular portions of the interventricular septum. A harsh pansystolic murmur is classically heard at the lower left sternal border.. This murmur is usually louder if the defect is small. Causes of ventricular septal defect may be congenital or acquired eg due to a myocardial infarct involving the septum.

Ventricular septal defect in wav format

Ventricular septal defect in real audio format





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