A presystolic murmur, also called presystolic accentuation, is a type of diastolic heart murmur typically associated with the opening snap in mitral valve stenosis. It is heard following the middiastolic rumble of the stenotic valve,[1] during the diastasis phase, making it a "late diastolic" murmur.

The murmur is heard due to antegrade flow of blood through a progressively narrowing mitral opening during the end of the atrial systole. This antegrade flow through the mitral valve before it completely closes appears to be the result of a pressure gradient at the end of diastole.[1] As its name so indicates, the presystolic murmur is heard before the mitral valve produces the S1 heart sound.

Less often, a presystolic murmur can be heard when a right atrial myxoma causes a tricuspid valve obstruction to blood flow.[1]

References

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  1. ^ a b c Eric J. Topol. The Topol Solution: Textbook of Cardiovascular Medicine, Third Edition with DVD, Plus Integrated Content Website, Volume 355. Lippincott Williams & Wilkins, Oct 19, 2006; page 222. ISBN 0781770122