This video is an animation of Fourth Heart Sound (S4) Gallop. While playing the animation, observe the
heart valves and blood flow, which are the source of heart murmurs.
This phonocardiogram of Fourth Heart Sound (S4) Gallop can be useful in learning to recognize the heart sound.
Play the sound and observe the phonocardiogram waveform (on this website, we typically show three
heart beats on each phonocardiogram).