| Fourth heart sound | |
|---|---|
| Other names | Atrial gallop, presystolic gallop |
.svg) | |
| Diagram of the heart. | |
| Specialty | Cardiology |
The fourth heart sound or S4 is an extra heart sound that occurs during late diastole, immediately before the normal two "lub-dub" heart sounds (S1 and S2). It occurs just after atrial contraction and immediately before the systolic S1 and is caused by the atria contracting forcefully in an effort to overcome an abnormally stiff or hypertrophic ventricle.
This produces a rhythm classically compared to the cadence of the word "Tennessee."[1][full citation needed][2] One can also use the phrase "A-stiff-wall" to help with the cadence (a S4, stiff S1, wall S2), as well as the pathology of the S4 sound.[3]
- ^ clinical examination A systemic guide to physical diagnosis
- ^ "Techniques - Heart Sounds & Murmurs Exam - Physical Diagnosis Skills - University of Washington School of Medicine". depts.washington.edu.
- ^ "The Fourth Heart Sound". The Auscultation Assistant - Rubs and Gallops. Archived from the original on 2018-09-13. Retrieved 2011-12-24.