| Third heart sound | |
|---|---|
| Other names | Ventricular gallop, protodiastolic gallop |
.svg) | |
| Diagram of the heart. | |
| Specialty | Cardiology |
The third heart sound or S3 is a rare extra heart sound that occurs soon after the normal two "lub-dub" heart sounds (S1 and S2). S3 is associated with heart failure.