Lecture 8 (heart Sounds/murmurs)

Question 1

How many sounds of the heart can be detected?

Answer 1

4

Question 2

1st heart sound - s1

Answer 2

Occurs at the onset of systole and the closing of AV valves

Change of flow from smooth to turbulent

Question 3

2nd heart sound - s2

Answer 3

2nd heart sound occurs with closure of the semilunar valves
Higher frequency my shorter duration
Splitting during inspiration (in humans)

Question 4

Intensity can be diminished with

Answer 4

Obesity, pleural, or pericardial effusions, decreased contractility

Question 5

Intensity may be increased in

Answer 5

Young, thin animals, increases contractility and anemia

Question 6

Heart sounds are generated by

Answer 6

The acceleration or deceleration of columns of blood

Question 7

3rd heart sound - s3

Answer 7

Occurs in early diastole
Corresponds to deceleration of blood flowing into ventricles
Not typically heard

Question 8

4th heart sound - s4

Answer 8

Occurs during atrial systole; low frequency, low intensity
Results from oscillation of blood and cardiac chambers during atrial contraction
Not usually heard (~horses)

Question 9

Heart murmur

Answer 9

Abnormal heart sound and often indicate the presence of cardiac abnormalities
Can be caused by turbulent flow through valvular defects
Congenital defect or acquired/degenerative
Stenosis or insufficient

Question 10

Heart murmur classification

Answer 10

Timing
Location
Intensity
Pitch
Shape

Question 11

Diastolic murmurs

Answer 11

Mitral or tricuspid stenosis

Aortic valve insufficiency (regurgitation)

Question 12

Systolic murmur

Answer 12

AV valve insufficiency
Aortic valve stenosis
Ventricular - septal defect

Question 13

Ventricular septal defect

Answer 13

Blood flows from the left to right ventricle during systole - creates systolic murmur

Question 14

Aortic/pulmonary stenosis

Answer 14

Systolic turbulence, narrowed valve region
Ventricular forces needed to eject the appropriate blood volume are much greater than normal
Degree. Of ventricular hypertrophy pressure proportional to degree of obstruction to forward flow

Question 15

Mitral +/- tricuspid valve degeneration

Answer 15

Blood is regurgitated from the ventricle into the atrium during systole when ventricular pressure is greater than atrial pressure
Very common in older dogs

Question 16

Aortic/pulmonary insufficiency

Answer 16

Diastolic murmur
Semilunar valve doesn’t close sufficiently
Increase in the diastolic filling or preload in the ventricles can lead to increased ventricular pressures
Degeneration (aortic valve common in horses)
Infection of valve (endocarditis)

Question 17

Aortic/pulmonary stenosis

Answer 17

Systolic turbulence, narrowed valve region
Ventricular forces needed to eject the appropriate blood volume are much greater than normal
Degree. Of ventricular hypertrophy pressure proportional to degree of obstruction to forward flow

Question 18

Mitral +/- tricuspid valve degeneration

Answer 18

Blood is regurgitated from the ventricle into the atrium during systole when ventricular pressure is greater than atrial pressure
Very common in older dogs

Question 19

Aortic/pulmonary insufficiency

Answer 19

Diastolic murmur
Semilunar valve doesn’t close sufficiently
Increase in the diastolic filling or preload in the ventricles can lead to increased ventricular pressures
Degeneration (aortic valve common in horses)
Infection of valve (endocarditis)