This lesson presents a mid-systolic click. It was auscultated at the mitral valve area. The first and second heart sounds are normal. The second heart sound is unsplit and no murmur is present so that you can concentrate on the systolic click. A mid-systolic click is often followed by a late systolic murmur of mitral valve leaflet prolapse. Use the 'Visual' tab to see the mitral valve posterior leaflet prolapse. The mid-systolic click is produced by the sudden prolapse of the leaflet.