Auscultation of Heart: Understanding Heart Sounds with Quiz and Flashcards

Study Notes

Auscultation

Auscultation is performed using the stethoscope diaphragm.

S1 - First Heart Sound

S1 is the loudest over the left fourth intercostal space (mitral/tricuspid valve areas).
S1 is produced when the mitral and tricuspid atrioventricular (A/V) valves close during ventricular contraction (systole).

S2 - Second Heart Sound

S2 is heard along the second right and left intercostal spaces (aortic/pulmonic valve regions).
S2 is produced when the pulmonic and aortic semilunar valves close during ventricular relaxation (diastole).

Identifying S1 and S2

The time between S1 and S2 is shorter than the time between S2 and the next S1, helping to identify which sound is produced by mitral/tricuspid valve closure and which is produced by aortic/pulmonic valve closure.

Physiologic Splitting of S2

A slight physiologic splitting of S2 is normal in younger patients.
Split S2 has two parts: aortic (A2) and pulmonic (P2) valve closure.
On inspiration, S2 splits into A2 and P2 due to delayed pulmonic valve closure.
On expiration, S2 is a single sound.

S1 and S2 Patterns

S1 doesn't split because mitral and tricuspid valve closure occur too closely together to be heard individually.

Extra Heart Sounds (S3 and S4)

S3 and S4 produce a gallop rhythm.
These sounds can be heard around the fourth intercostal space on the mid-clavicular line.
They are considered normal up to ages 20-30.

Description

Learn about the cardiac examination technique of auscultation, including the identification of the first and second heart sounds, S1 and S2, and their locations in the thoracic cavity. Understand the valves and events associated with these sounds. Test your knowledge of cardiac physiology and auscultation!