Continuous murmurs

Image:Phonocardiograms from normal and abnormal heart sounds.svg from normal and abnormal heart sounds]]

Heart murmurs are most frequently organized by timing, into systolic heart murmurs and diastolic heart murmurs. However, continuous murmurs can not be directly placed into either category.{{DorlandsDict|nine/000954882|continuous murmur}}

These murmurs are due to blood flow from a high pressure chamber or vessel to a lower pressure system.

• Patent ductus arteriosus . Patent ductus arteriosus (PDA) is an abnormal connection between the aorta and the pulmonary artery, which normally should be closed in infancy. Since aortic pressure is higher than pulmonary pressure, a continuous murmur occurs. This murmur is often described as a machinery murmur, or Gibson's murmur.{{DorlandsDict|five/000068110|Gibson murmur}}{{dead link|date=February 2019}} This is named for George Alexander Gibson, who characterised it in 1898.Gibson GA 1898 Diseases of the heart and aorta. Pentland, Edinburgh, pp 61, 303, 310–312{{cite journal |author=Tynan M |title=The murmur of the persistently patent arterial duct, or "The Colonel is going to a dance" |journal=Cardiol Young |volume=13 |issue=6 |pages=559–62 |date=December 2003 |pmid=14982298 }}
• Aortopulmonary window.
• Shunts. Usually a left to right shunt through a small atrial septal defect in the presence of mitral valve obstruction.