A nurse is auscultating a client’s heart sounds and hears an extra heart sound before what should be considered the first heart sound S1. The nurse should document this finding as which of the following heart sounds?
A.
A friction rub
B.
A split second heart sound S₂
C.
The third heart sound (S3)
D.
The fourth heart sound (S4)
When auscultating heart sounds, the nurse may encounter extra sounds that provide important information about cardiac function. Each type of extra heart sound has specific characteristics and timing:
A. A friction rub
- Explanation: A friction rub is a scratchy or grating sound heard due to inflammation of the pericardial layers. It is not an extra heart sound that occurs before the first heart sound (S1).
B. A split second heart sound S₂
- Explanation: A split S₂ is a normal physiological variation where the second heart sound (S₂) is split into two distinct components, usually heard during inspiration. It does not occur before S1.
C. The third heart sound (S3)
- Explanation: The third heart sound (S3) is often described as a “gallop” and occurs after the second heart sound (S₂). It is considered an extra heart sound and can be normal in children and young adults, or indicative of heart failure in older adults. This sound occurs after S2, not before S1.
D. The fourth heart sound (S4)
- Explanation: The fourth heart sound (S4) is also known as an “atrial gallop” and occurs just before the first heart sound (S1). It is caused by the atria contracting against a stiff or hypertrophied ventricle. It is often associated with conditions like hypertension or heart failure.
Conclusion: An extra heart sound heard before S1 is the fourth heart sound (S4), not S3, a split S₂, or a friction rub.
The correct answer is D. The fourth heart sound (S4).