Cardiac Auscultation in the Horse Flashcards
4 manifestations of endocardial disease in horses?
- Cardiac murmur (most common)
- Poor performance (rare)
- Collapse / sudden death (rare)
- Congestive heart failure (rare)
Differentials of a cardiac murmur?
- Physiological murmur
- Murmur caused by valvular and congenital abnormality
What does jugular distension indicate?
- Jugular distension is an indicator of reduced cardiac return
- Right sided Cardiac failure
- Thoracic disease
- Pericardial disease
What can peripheral oedema indicate?
- Can be a sign of right sided heart failure
- But this is not the only cause of peripheral oedema. Other causes include…
- Hypoproteineamia
- Vascular disease
Where should jugular pulsation be visible in the normal horse?
- Normally visible in distal third of neck (shouldn’t extend further up the neck)
- Dependant on head and neck position
What type of oedema would you see with left sided heart failure?
Pulmonary oedema
What type of oedema would you see with right sided heart failure?
Peripheral oedema
What are the normal heart sounds?
- S4 (shh)
- S1 (Lub)
- S2 (Dub)
- S3 (de)
What is S4?
- First part of cardiac cycle
- Onset of atrial systole
What is S1?
- Onset of ventricular systole
- Closure of AV valves opening of Semilunar valves
Where is S1 loudest?
Loudest over LIC 5
What is S2?
- Onset of diastole
- Closure of semilunar valves, open AV
Where is S2 loudest?
Loudest over LIC 4
What is S3?
- Just after opening of AV valves
- Rapid ventricular filling
Where is S3 loudest?
Loudest over cardiac apex (low LIC5)
What causes normal heart sounds?
- Heart sounds caused by turbulence
- Typically associated with:
- Closure of cardiac valves
- High velocity flow
- Typically associated with:
What causes cardiac murmurs?
- Forward or reverse flow
- Typically leakage of fluid through a closed valve
How would you assess cardiac murmurs in the horse?
- Cardiac auscultation
- History and physical examination
- Do they have signs of cardiac compromise?
- Echocardiography
- Electrocardiography
How are murmurs classified?
- Grade / Intensity
- Timing (Systole vs Diastole)
- Radiation
- Point of maximal intensity
What is a grade 1 murmur?
Quiet murmur often difficult to identify
What is a grade 2 murmur?
Murmur quieter than heart sounds
What is a grade 3 murmur?
Murmur as loud as S1 and S2
What is a grade 4 murmur?
Murmur louder than S1 and S2
What is a grade 5 murmur?
Loud cardiac murmur with a precordial thrill
(buzz and vibration that you can feel with hand on the chest wall)
What is a grade 6 murmur?
Murmur audible with stethoscope off thoracic wall
Which terms are used to refer to where in the cardiac cycle the murmur occurs?
- Holo - systolic (or diastolic) (between the heart sounds)
- Between cardiac sounds
- Pan – Systolic
- Across heart sounds (will mask the heart sounds)
- Mid- Systolic
What happens in Endocardiosis?
- Valvular degeneration – progressive
- Mitral, aortic, tricuspid valves
What happens in Endocardititis?
Bacterial in origin secondary to bacteraemia
Causes of endocarditis?
- Cattle: Liver abscess, TRP, mastitis
- Equine: Dental, respiratory, thrombophlebitis
- Other causes
- Valve dysplasia
- Valvulitis
- Valve prolapse
- Ruptured chordae tendinae
Clinical signs of Bacterial endocarditis?
- Acute onset Congestive heart failure
- Fever, cardiac murmur, tachycardia, tachypnoea
Treatment of bacterial endocarditis?
Start on broad spectrum antibiotics ideally based on sensitivity
Prognosis of bacterial endocarditis?
- Guarded even after bacteriological cure
- Permanent structural damage to valve
- Septic emboli may shed to distant sites
