Cardiac Murmurs in the Horse

Question 1

Difference between endocardiosis and endocardititis?

Answer 1

• Endocardiosis
  
  • Valvular degeneration – progressive (part of the aging process)
• Endocardititis
  
  • Bacterial in origin secondary to bacteraemia

Question 2

Clinical signs of bacterial endocarditis?

Answer 2

• Acute onset Congestive heart failure
• Fever, cardiac murmur, tachycardia, tachypnoea

Question 3

What diagnostics and lab findings for bacterial endocarditis?

Answer 3

• Hyperfibrinogenaemia, anaemia and leucocytosis
• Blood culture
  
  • Repeat x3 (false negatives) ideally when pyrexic
  • Sterile procedure

Question 4

Common Differentials for a systolic murmur (left)?

Answer 4

1. Mitral insufficiency
2. Aortic flow
3. Pulmonic flow

Question 5

What type of murmur would you get with mitral insufficiency?

Answer 5

• Grade: 1 – 6 /6
• Timing: Early, mid, holo, pan- systolic
• Shape: Band Shaped
• Loudest: Left 5th intercostal space
• Radiates: Caudodorsally

Question 6

Signalment and clinical signs of mitral insufficiency?

Answer 6

• Signalment : All age groups
• Clinical signs:
  
  • Incidental finding
  • Poor Performance
  • Atrial fibrillation
  • left-sided failure (Acute onset)
  • Right-sided failure
  • Collapse, fainting or sudden death

Question 7

What are the indications for echocardiography for horses with mitral regurgitation?

Answer 7

• Grade > 3/6
• Loud third heart sound
• Resting tachycardia
• Fever
• Poor performance
• Arrhythmias

Question 8

Characteristics of a murmur caused by aortic ejection?

Answer 8

• Loudest over left 4th intercostal space (cranially)
• Intensity - Usually < 3
• Timing - Usually early to mid systolic
• Radiation - Cranio-dorsal
• Shape - Crescendo decrescendo / Decrescendo

Question 9

Common differentials for a systolic murmur (right)?

Answer 9

1. Tricuspid insufficiency
2. Ventricular septal defect

Question 10

Tricuspid insufficiency is common in which breeds?

Answer 10

Common in racing Thoroughbreds and Standardbreds

Question 11

Characteristics of a murmur caused by tricuspid insufficiency?

Answer 11

• Grade : 1 - 6/6
• Timing: Holo or pansystolic
• Shape: Crescendo-decrescendo or Band-shaped
• Loudest: Right 4th intercostal space
• Radiates: Craniodorsally

Question 12

In which breed are ventricular septal defects common?

Answer 12

• Common in welsh ponies

Question 13

How significant are ventricular septal defects?

Answer 13

• Size of defect determines significance
  
  • If small can be athletes

Question 14

Differentials for diastolic murmurs?

Answer 14

1. Ventricular filling
2. Aortic insufficiency
3. Pulmonic insufficiency

Question 15

Which horses tend to get aortic insufficiency?

Answer 15

• Middle-aged or older horses
• Frequently an incidental finding
• Progressive condition clinical signs in older horses

Question 16

Murmur characteristics of aortic insufficiency?

Answer 16

• Grade: 1-6/6
• Timing: Early or holo DIASTOLIC
• Shape: Decrescendo
• Loudest: Left 4th intercostal space (often audible on right hand side)
• Radiates: Caudoventrally

Question 17

Causes of Cardiac Murmurs that are well-tolerated?

Answer 17

• Physiological murmurs
• Tricuspid and many mitral insufficiencies in athletes, provided that there are no structural valvular lesions
• Slowly progressive aortic insufficiency in middle-aged horses
• Acute onset lesions e.g. ruptured chorda tendinea, bacterial endocarditis, valvular insufficiency associated with myocardial pathology
• Valvular insufficiencies with concurrent arrhythmias
• Progressive lesions