Certified Medical-Surgical Registered Nurse Practice Exam

How should an extra heart sound immediately after the second heart sound (S2) be documented?

1. A first heart sound (S1)

2. A third heart sound (S3)

3. A fourth heart sound (S4)

4. A mitral murmur

The correct answer is: A third heart sound (S3)

The documentation of an extra heart sound occurring immediately after the second heart sound (S2) should be noted as a third heart sound (S3). The S3 heart sound, also known as a ventricular gallop, is a low-frequency sound that typically occurs shortly after S2 when the rapid filling phase of the ventricles begins. It can be normal in certain populations, such as children and pregnant women, and may indicate heart failure or volume overload in others. Recognizing and documenting this sound accurately is crucial as it provides important clinical information regarding the heart's functioning and volume status. In contrast, a first heart sound (S1) occurs with the closing of the atrioventricular valves at the beginning of ventricular contraction, while the fourth heart sound (S4), known as an atrial gallop, occurs just before S1, typically due to increased resistance to ventricular filling. A mitral murmur pertains to an abnormal sound caused by turbulent blood flow through the mitral valve and is distinct from S3, as it represents a different physiological phenomenon. Thus, documenting the sound correctly as S3 is essential for accurate patient assessment and management.