Murmurs

Question 1

Grade III/VI or less left heart base systolic ejection murmur

Answer 1

Functional (physiological murmur)

Question 2

What is a functional murmur?

Answer 2

Associated with rapid ejection of blood in early systole

Question 3

What is the most common congenital cardiac defect in the foal?

Answer 3

Ventricular septal defect

Question 4

T/F: often ventricular septal defects are incidental findings on physical exam

Answer 4

True

Or can present for poor performance and exercise intolerance

Question 5

Pan-systolic murmur, grade III-IV/VI with the PMI at the 3rd or 4th ICS

Murmur can be heard on the right, one grade higher than the left

Answer 5

Ventricular septal defect

Question 6

Why is VSD often associated with a grade III-IV murmur over the left heart base ?

Answer 6

Increased flow over the pulmonic valve —> relative pulmonic stenosis .

Question 7

What is the prognosis for a VSD?

Answer 7

If 2.5cm or less —> usually normal growth and performance

Larger VSD—> volume overload to the left heart and poor growth and performance

Question 8

Murmur grade II-IV/VI with continuous (systolic/diastolic) machinery murmur with PMI in the dorsal left 4th ICS

Answer 8

Patent ductus arteriosus (PDA)

Question 9

When is a PDA murmur not pathologic?

Answer 9

If heard in the first 72-96hours of birth

Question 10

Closure of the ductus arteriosus is triggered by?

Answer 10

Increased arterial O2 tension and decreased flow

—> occurs initially by vascular constriction followed by muscular and fibrosis

Question 11

What kind of shunt is present in a PDA?

Answer 11

L to R shunt

Question 12

In foals, the ductus arteriosus can appear to close but can reopen due to?

Answer 12

Systemic illness or hypoxia

—> until fibrosis the ductus is only closed by vasoconstriction and can be reopened

Question 13

Clinical signs associated with mitral valve insufficiency?

Answer 13

Exercise intolerance
Weight loss
Signs of CHF (tachycardia, jugular vein distention, resp distress, SQ edema, and ascites)

Question 14

What is the most common cause of mitral valve insufficiency?

Answer 14

Degenerative changes to valve

Also the most common site for bacterial endocarditis

Question 15

Severe damage of the mitral valves or leaflets can result in spontaneous rupture of??

Answer 15

Chordae tendinae

Question 16

Grade III or greater, holosystolic/pansystolic murmur with PMI at 5th ICS

Answer 16

Mitral valve

Question 17

If a mitral valve murmur is associated with chordae tendinae rupture, how will the murmur sound?

Answer 17

Extremely loud honking murmur

Question 18

When do you have a poor prognosis associated with mitral valve insufficiency ?

Answer 18

More sever valve dysfunction —> leads to progressive CHF

Presence of dilated pulmonary artery (unsafe to ride)

Question 19

T/F: aortic valve insufficiency is usually asymptomatic

Answer 19

True

Question 20

Large regurgitation due to aortic insufficiency can lead to volume overload of the ________

Answer 20

Left ventricle

Question 21

What is usually the cause of aortic insufficiency ?

Answer 21

Degenerative changes to aortic valve

—> nodules, fibrous bands and plaques

Question 22

Grade II-IV/VI pan-, holo-, diastolic murmur with PMI at 4th left ICS

Answer 22

Aortic insufficiency

Question 23

What breed is predisposed to tricuspid insufficiency?

Answer 23

Thoroughbreds

Question 24

Clinical signs associated with tricuspid insufficiency?

Answer 24

Exercise intolerance (RARE)

Pathological changes at this valve are uncommon, common site for physiological regurgitation

Question 25

What is the prognosis for tricuspid insufficiency ?

Answer 25

Good prognosis for continued performance

Poor if accompanied by atrial fibrillation as typical reflects concurrent severe mitral insufficiency

Question 26

Right sided holo-, pan-systolic murmur

Answer 26

Tricuspid insufficiency

Question 27

What valves are most commonly affected by vegetative endocarditis ?

Answer 27

Mitral and aortic

Question 28

What is the pathogenesis of vegetative endocarditis?

Answer 28

Structural damage to the endothelium —> formation of microscopic thrombi along valvular surface

Fibrous clot formation/vegetation’s

Question 29

What are hemodynamic causes of endothelial trauma?

Answer 29

Regurgitant jets
Narrow orifices
High pressure gradients
Sepsis of the valve
Adhered bacteria grow in laminar network of fibrin
Local release of thromboplastin activates coagulation (extrinsic pathway)

Question 30

Clinical signs associated with vegetative endocarditis ?

Answer 30

Fever of unknown origin (FUO) 
Intermittent or continuous fever 
Tachycardia, tachypnea 
Cardiac murmur 
—> systolic if AV valves
—> diastolic if semilunar valves

Question 31

What diagnostics can you do to confirm vegetative endocarditis?

Answer 31

Chem

• hyperproteinemia (hyperglobulinemia and hyperfibrinogenemia)
• leukocytosis
• non-regenerative anemia (typical of chronic dz)

Blood culture
ECG
Echo —> affected valve leaflets is thickened, irregular, with globular hyperechoci mass on free edge

Question 32

What bacteria are most frequently the cause of vegetative endocarditis?

Answer 32

Strep sp, Actinobacillus equuli, and Ecoli

Question 33

What arrhythmia is common if there is mitral valve insufficiency and LA enlargement due to vegetative endocarditis ?

Answer 33

Afib

Question 34

What is the treatment for vegetative endocarditis?

Answer 34

Antimicrobial for minimum 4-6weeks
—> K-pen IV and gentamicin

Anti inflammatory
—> phenylbutazone or flunixin meglumine
—> aspirin (decrease platelet aggregation)

AF, cardiac failure, and VPC
—> digoxin if CO is compromised
—> diuretics to decrease volume overload

Question 35

What is more common, left or right sided HR in the equine patient?

Answer 35

Horses will typically have signs of both, it is usual for the horse to quickly involve the other part of the circulation when one side fails