Repetition Training - Basic Heart Sounds Mitral Stenosis (Diastolic Murmur) Lesson Waveform Anatomy play pause Table of Contents 1Third Heart Sound Gallop 2Fourth Heart Sound Gallop 3Aortic Stenosis (Diamond Shaped Systolic Murmur) 4Aortic Regurgitation - Moderate 5Mitral Stenosis (Diastolic Murmur) 6Mitral Regurgitation 7Innocent Murmur Practice Quiz This video is an animation of Mitral Stenosis (Diastolic Murmur) A#401 (lesson# 5) within course number 5. This is an example of a diastolic decrescendo murmur occurring after an opening snap. It is associated with mitral stenosis.The first heart sound is increased in intensity while the second heart sound is normal. An opening snap is present after the second heart sound. The low pitched rumbling murmur starts after the opening snap and lasts until mid diastole.On the anatomy tab you can see an enlarged left atrium and thickened but mobile mitral leaflets.Turbulent blood flow from the left atrium into the left ventricle is responsible for the murmur.