Heart Sounds and Murmurs

Question 1

What physical property is the basis of heart sounds?

Answer 1

Turbulence

Question 2

What physical action produces S1? What does it sound like?

Answer 2

Closure of the AV valves; “Lub”

Question 3

What can S1 be split into? What is the basis of this splitting?

Answer 3

The two AV valves do not close at exactly the same time and so there are two sounds: M1 (mitral closure) and T1 (tricuspid closure)

Question 4

Which ventricle contributes more to the 1st heart sound?

Answer 4

The left

Question 5

What is typically the loudest heart sound? Why is it the loudest?

Answer 5

S1 is generally louder because there is a bigger pressure change across the AV valves than across the semilunar valves

Question 6

What is the sound of S2? What produces this sound?

Answer 6

“dub”; produced by closure of semilunar valves

Question 7

What can S2 be split into? Which occurs first?

Answer 7

A2 and P2; A2 happens first

Question 8

Which side of the heart contributes more to the 2nd heart sound?

Answer 8

Right

Question 9

When can S3 be heard? What can it be indicative of if heard in adults?

Answer 9

Early diastole; Can be indicative of ventricular dysfunction (problems w/ ventricular compliance)

Question 10

When can S4 be heard? What can it be indicative of if heard?

Answer 10

Occurs in late diastole during atrial systole; can reveal problems with ventricular compliance or atrial contraction

Question 11

What does splitting of S1 generally indicate? What problem might cause this?

Answer 11

Delay in right ventricular contraction; Right bundle branch block

Question 12

Splitting of which sound is more common?

Answer 12

S2

Question 13

What does splitting of S2 generally indicate? What problem might cause this?

Answer 13

Indicates delay in the emptying or contracting of the right ventricle; Pulmonary hypertension

Question 14

What normal physiologic process accentuates splitting?

Answer 14

Inspiration

Question 15

Why does inspiration accentuate splitting?

Answer 15

Inspiration results in decreased intrathoracic pressure and increased abdominal pressure, increasing venous return and EDV. Increased EDV takes longer time for volume ejection and T1 and P2 will be more likely to split, esp. P2 from A2

Question 16

What technique allows heart sounds to be visualized?

Answer 16

Phonocardiogram

Question 17

Between what heart sounds does systole occur?

Answer 17

S1 and S2

Question 18

Between what heart sounds does diastole occur?

Answer 18

S2 and S1

Question 19

What are murmurs?

Answer 19

Abnormal heart sounds due to turbulence caused by abnormal pressure gradients

Question 20

Murmur classification is based on what criteria?

Answer 20

Intensity, quality, duration, and timing of sound

Question 21

How is intensity of murmurs graded?

Answer 21

On a scale of I-V where V is loudest

Question 22

What are the major types of valvular dysfunction?

Answer 22

Stenosis and Regurgitation/ insufficiency

Question 23

How can stenosis result in hypertrophy? What formula explains this response?

Answer 23

Stenosis leads to an increase in the resistance that the first chamber must push against, which leads to hypertrophy; Law of LaPlace- Stress= (P*r)/wall thickness

Question 24

What is the anatomical basis of valvular regurgitation/ insuffiecincy?

Answer 24

The valve does not form a complete seal when it tries to close meaning some blood leaks backwards

Question 25

In what phase of the cardiac cycle would an aortic stenosis be heard?

Answer 25

Systole

Question 26

How would aortic stenosis be manifested on a pressure vs. time graph of the caridac cycle?

Answer 26

The LVP will be much greater than aortic pressure over the course of stroke ejection

Question 27

When will a murmur due to aortic stenosis end?

Answer 27

A2 portion of S2

Question 28

What kind of volume profile will a murmur due to aortic stenosis have?

Answer 28

Crescendo follwed by decrescendo

Question 29

What kind of hypertrophy occurs in response to aortic stenosis?

Answer 29

Concentric hypertrophy

Question 30

How can aortic stenosis result in heart failure?

Answer 30

Increased stenosis leads to increased resistance and the ventricle can only hypertrophy so much to compensate for that

Question 31

When will regurgitation across the mitral valve occur the most?

Answer 31

When the pressure gradient btw LV and LA is the greatest, i.e. the ejection phase

Question 32

When does the murmur begin with mitral insufficiency? How can the duration of the murmur be described?

Answer 32

M1; pansystolic or holosystolic

Question 33

How would mitral insufficiency be manifested on a pressure vs. time graph of the caridac cycle?

Answer 33

LAP will be much higher during systole than expected

Question 34

What is the main distinguishing feature of aortic insufficiency?

Answer 34

Increased pulse pressure

Question 35

What type of hypertrophy is seen with aortic insufficiency?

Answer 35

Eccentric hypertrophy

Question 36

What is eccentric hypertrophy?

Answer 36

An increase in ventricular length rather than width

Question 37

When does mitral valve stenosis occur?

Answer 37

Diastole

Question 38

Where is concentric hypertrophy developed in with mitral valve stenosis?

Answer 38

Left atrium