Heart Sounds Flashcards

Questions and Answers

When does the S1 heart sound occur?

At the beginning of systole (end of diastole).

What causes the S1 heart sound?

Related to the closure of the mitral and tricuspid valves.

When does the S2 heart sound occur?

At the beginning of diastole (end of systole).

What causes the S2 heart sound?

Related to the closure of the aortic and pulmonic valves. Signup and view all the answers

When does the S3 heart sound occur?

Low frequency sound in early diastole, 120 to 180 ms after S2. Signup and view all the answers

Why does the S3 heart sound occur?

Results from increased atrial pressure leading to increased flow rates. Signup and view all the answers

What are the causes of the S3 heart sound?

The most common cause is congestive heart failure; less common causes include valvular regurgitation and left to right shunts. Signup and view all the answers

When does the S4 heart sound occur?

Low frequency sound just after atrial contraction ('atrial kick') at the end of diastole and immediately before S1. Signup and view all the answers

Why does the S4 heart sound occur?

Seen in patients with stiffened left ventricles due to conditions like hypertension, aortic stenosis, ischemic or hypertrophic cardiomyopathy. Signup and view all the answers

During S1, which valve closes first?

The mitral valve closes before the tricuspid valve. Signup and view all the answers

During S2, which valve closes first?

The aortic valve closes before the pulmonic valve. Signup and view all the answers

Study Notes

Heart Sounds Overview

S1 heart sound marks the beginning of systole, occurring at the end of diastole.
S1 is caused by the closure of the mitral and tricuspid valves.

S2 Heart Sound

S2 heart sound indicates the start of diastole, occurring at the end of systole.
It is produced by the closure of the aortic and pulmonic valves.

S3 Heart Sound

S3 is a low-frequency sound occurring in early diastole, approximately 120 to 180 ms after S2.
It arises from increased atrial pressure and higher flow rates.

Causes of S3

The most common cause is congestive heart failure.
Less frequently associated with valvular regurgitation and left-to-right shunts.

S4 Heart Sound

S4 is a low-frequency sound that occurs just after atrial contraction (atrial kick) at the end of diastole, right before S1.
It is commonly seen in patients with stiffened left ventricles due to conditions like hypertension, aortic stenosis, ischemic, or hypertrophic cardiomyopathy.
In cases of mitral regurgitation, it may indicate acute regurgitation due to ruptured chordae tendineae.

Valve Closure Timing in Heart Sounds

During S1, the mitral valve closes before the tricuspid valve.
During S2, the aortic valve closes before the pulmonic valve.

Description

Test your knowledge on heart sounds S1, S2, S3, and S4 with these flashcards. Learn when each sound occurs and what causes them, focusing on the physiological events during the cardiac cycle. Perfect for students in medical or nursing programs.