Heart Sounds

Question 1

What produces normal heart sounds

Answer 1

The closure of heart valves

Question 2

What causes the normal S1 and S2 sound (lub dub)

Answer 2

S1 - Mitral and Tricuspid Valve Closure
S2 - Aortic and Pulmonic Valve Closure

Question 3

What are abnormal heart sounds

Answer 3

When a normally silent event in the heart becomes audible

Question 4

What is the S3 heart sound (abnormal)

Answer 4

Its a soft dull sound that follows immediately after S2 during early diastole. Its said that it sounds like a gallop.

It is caused when the ventricles of the heart have reduced lung compliance (doesn’t stretch as much) and therefore the blood has a more forceful impact on the ventricular wall, creating an abnormal heart sound.

Question 5

What can cause reduced ventricular compliance

Answer 5

• Aging (40+)
• Diseases of heart muscle (cardiomyopathy)
• Diabetes
• Inflammation (myocarditis)
• Fibrosis (scarring from previous heart attacks or diseas)

Question 6

What is the S4 Sound

Answer 6

This occurs when the atria contract and push blood into a stiff ventricle.

It occurs just before S1 and is also a low dull sound

Question 7

Whats the difference between S3 and S4

Answer 7

The sound in S3 is caused by the passive flow of blood into the ventricle

S4 is caused by the active pushing of blood into the stiff ventricle

Question 8

What are heart murmurs caused by (simple)

Answer 8

Turbulent blood flow between cardiac chambers

Question 9

What are the causes of Heart Murmurs

Answer 9

• Narrowing of a heart valve
• Leakage of a valve backwards
• Congenital heart defects
• Increased blood flow such as in pregnancy
• Ventricular Hypertrophy
• Infection (endocarditis)