Heart Murmurs

Question 1

What are the 4 heart sounds?

Answer 1

S1 - AV valves close to prevent backflow into atria due to ventricular contraction
S2 - Aortic and pulmonary (semi-lunar) valves close
S3 - Vibration of ventricular wall during rapid passive filling (Gallop)
S4 - Ventricular filling due to atrial contraction

Question 2

What is a murmur?

Answer 2

Abnormal cardiac sounds caused by turbulent blood flow

Question 3

Physiological murmur cause

Answer 3

Viscosity change

Question 4

Pathological murmur cause

Answer 4

Acquired or congenital disease

Question 5

What is a gallop sound?

Answer 5

S3 - Vibration of ventricular wall during rapid passive filling (Gallop)

Question 6

When are gallop sounds audible?

Answer 6

• Gallop sounds are audible in the presence of myocardial disease - S3
  ○ Vibration of ventricular wall during rapid passive filling (Gallop)
  ○ Caused by the sound of blood rushing into a non-compliant stiff left ventricle
  ○ Often associated with a poor prognosis

Question 7

When do gallop sounds occur?

Answer 7

Early diastole
Cats - HCM
Dogs - DCM

Question 8

When do systolic murmurs occur?

Answer 8

Between S1 and S2
* Aortic/pulmonic stenosis
* Mitral or tricuspid regurgitation
* Mitral valve dysplasia
* ASD/VSD

Question 10

What is a continuous murmur a sign of?

Answer 10

Patent ductus arteriosus