Heart sound

Heart sound refers to the noise produced by the beating heart and the resultant flow of blood through it. Specifically, the sounds reflect the turbulence created when the heart valves snap shut. In cardiac auscultation, an examiner may use a stethoscope to listen for these unique and distinct sounds that provide important auditory data regarding the condition of the heart.

Types of Heart Sounds

There are two primary types of heart sounds, namely S1 and S2. These are high-frequency sounds that occur with each heartbeat. S1 is the sound created by the closing of the atrioventricular valves during ventricular contraction (systole), while S2 is the sound of the closing of the semilunar valves during ventricular relaxation (diastole).

In addition to S1 and S2, two other heart sounds may be heard in certain conditions: S3 and S4. These are low-frequency sounds that are usually associated with pathological conditions of the heart.

Clinical Significance

The characteristics of heart sounds can provide valuable diagnostic information. For instance, variations in the normal heart sounds may indicate heart abnormalities or disease. A heart murmur is an abnormal sound that is heard in addition to the normal heart sounds. It is usually due to turbulent blood flow within the heart.

See Also

• Cardiac cycle
• Cardiac examination
• Heart murmur
• Stethoscope

References

Heart sound Resources
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