Monday Lectures

Question 1

What is pressure?

Answer 1

Force applied to a surface per unit area

Question 2

What two things does blood pressure rely on?

Answer 2

Location and phase of cardiac cycle

Question 3

What are the two components of blood pressure?

Answer 3

Cardiac output/flow and resistance

Question 4

What are the two components of cardiac output/flow?

Answer 4

Stroke volume and heart rate

Question 5

What is the formula for resistance in a blood vessel?

Answer 5

Resistance = 8(length of the vessel)(viscosity of the blood)/3.14…(radius of the blood vessel)^4)

Question 6

What is the most important factor that resistance depends on?

Answer 6

Radius of the vessel

Question 7

What is the minimum systolic blood pressure necessary to be considered systemic hypertension?

Answer 7

Systolic BP > 160mmHg

Question 8

What are the three different types of systemic hypertension?

Answer 8

Situational, secondary, and idiopathic

Question 9

What is situational hypertension?

Answer 9

White coat syndrome → increased BP as a consequence of in-clinic measurement process

Question 10

What is the main body system that is activated in relation to white coat syndrome?

Answer 10

Autonomic nervous system

Question 11

Are animals with situational hypertension normotensive?

Answer 11

Yes

Question 12

What can the persistent and pathologically increased blood pressure that defines secondary hypertension be due to? Three answers.

Answer 12

Disease/condition, therapeutic agent, and toxic agent

Question 13

What two diseases are the most commonly found diseases to be affecting blood pressure and therefore causing secondary hypertension?

Answer 13

Renal and endocrine diseases

Question 14

Listed below are the 4 mechanisms through which renal disease can cause secondary hypertension, give the blood pressure component (cardiac output and resistance) that will be affected:
- Sodium and fluid retention

• RAAS hyperactivation → increased sodium retention and vasoconstriction

Answer 14

• Sodium and fluid retention (Increased cardiac output)
• RAAS hyperactivation → increased sodium retention and vasoconstriction (Increased cardiac output and resistance)

Question 15

Listed below are the 4 mechanisms through which renal disease can cause secondary hypertension, give the blood pressure component (cardiac output and resistance) that will be affected:
- SNS hyperactivation → increased sodium retention and vasoconstriction

• Vascular endothelial dysfunction → impaired NO production

Answer 15

• SNS hyperactivation → increased sodium retention and vasoconstriction (Increased cardiac output and resistance)
• Vascular endothelial dysfunction → impaired NO production (Increased resistance)

Question 16

What are the two mechanisms of action that endocrine disease can cause secondary hypertension?

Answer 16

RAAS activation and increased sensitivity to aldosterone?

Question 17

Is the systemic hypertension found related to hyperadrenocorticism/Cushing’s disease reversible?

Answer 17

Can be also cannot be

Question 18

What organ system does diabetes affect that leads to increased blood pressure?

Answer 18

Renal

Question 19

Why do pheochromocytomas cause episodic systemic hypertension, making it hard to diagnose?

Answer 19

The catecholamine release due to pheochromocytomas is episodic and the systemic hypertension is related to the catecholamine release

Question 20

What are the two mechanisms by which hyperthyroidism causes secondary hypertension, especially in cats?

Answer 20

Increase cardiac output and increase sensitivity to sympathetic activation

Question 21

Is the increase in blood pressure related to hyperthyroidism in cats mild or severe?

Answer 21

Mild

Question 22

What two therapeutic agents can cause hypertension?

Answer 22

Corticosteroids and alpha agonists

Question 23

What is the persistent and pathologically increase in blood pressure in absence of an identifiable underlying cause?

Answer 23

Idiopathic hypertension

Question 24

Do cardiac diseases cause systemic hypertension?

Answer 24

No

Question 25

Can systemic hypertension cause cardiac disease?

Answer 25

Yes

Question 26

Why does systemic hypertension cause cardiac disease?

Answer 26

It increased afterload of the heart

Question 27

What type of overload and hypertrophy does systemic hypertension cause?

Answer 27

Pressure overload → concentric hypertrophy

Question 28

Is the heart disease due to systemic hypertension mild or severe?

Answer 28

Mild

Question 29

What are the four organs that are particularly sensitive to systemic hypertension?

Answer 29

Kidney, eye, brain, and heart/vessels

Question 30

What are the two renal sequela of systemic hypertension?

Answer 30

Decrease in renal function and early renal death

Question 31

What would indicate the above renal issues that you could monitor in your patient? - Above question: What are the two renal sequela of systemic hypertension? (Decrease in renal function and early renal death)

Answer 31

Increased renal values → BUN, creatinine; proteinuria

Question 32

What is the ocular sequelae of systemic hypertension?

Answer 32

Retinal detachment

Question 33

How would a patient with the above ocular systemic hypertension sequelae present to you? (Retinal detachment)

Answer 33

With acute onset of blindness

Question 34

Is systemic hypertension a frequent sole cause of congestive heart failure?

Answer 34

No, infrequent

Question 35

What blood pressure does the doppler cuff method give you?

Answer 35

Systolic

Question 36

Will a narrow blood pressure cuff over or underestimate blood pressure?

Answer 36

Overestimate

Question 37

What is the first line choice of drug for severe hypertension (>200mmHg)?

Answer 37

Calcium channel blocker → amlodipine

Question 38

What drug would you choose for cats with uncontrolled hyperthyroidism and that is contraindicated in dogs with pheochromocytomas?

Answer 38

Beta blockers → atenolol

Question 39

If you are treating a cat for systemic hypertension and it also has proteinuria, what drugs would you use to treat this cat?

Answer 39

ACE inhibitor and calcium channel blockers → benazepril and amlodipine

Question 40

Which of the drugs chosen above would you remove if the cat does not have proteinuria?

Answer 40

Benazepril

Question 41

What abnormalities of the heart give it a ‘reverse D’ appearance on radiography?

Answer 41

Right heart and main pulmonary artery enlargement

Question 42

Why do R → L shunt patients not respond to oxygen supplementation?

Answer 42

Because blood is skipping systemic circulation so higher levels of oxygen in systemic circulation isn’t going to help

Question 43

What are the four cyanotic heart diseases?

Answer 43

rPDA, R to L VSD, R to L ASD/PFO, and tetralogy of fallot

Question 44

Why are animals with cyanotic heart diseases at a higher risk of ventricular arrhythmias?

Answer 44

They will have concentric hypertrophy of the right ventricle d/t PH and PS + decreased oxygen content of blood = myocardium not getting enough oxygen → myocardium dies off → ventricular arrhythmias

Question 45

If you see a GSD patient with a bad ventricular arrhythmia, what disease do they have?

Answer 45

Inherited ventricular arrhythmia

Question 46

What are the breeds associated with juvenile dilated cardiomyopathy?

Answer 46

Portuguese water dog, doberman, and toy terriers

Question 47

What is the term for transient loss of consciousness resulting from a decrease in cerebral perfusion?

Answer 47

Syncope

Question 48

What are the three causes of syncope?

Answer 48

Cardiovascular, reflex mediated, and orthostatic hypotension

Question 49

What do all cardiovascular abnormalities/diseases/conditions do that cause syncope?

Answer 49

Reduce cardiac output

Question 50

What are the two groups of cardiovascular abnormalities that cause cardiovascular syncope?

Answer 50

Arrhythmias and others → structural obstructive heart diseases, pulmonary hypertension/PTE, pericardial effusion and congestive heart failure

Question 51

What about the patient history would be more highly indicative of arrhythmic cardiovascular syncope?

Answer 51

If they animal is normal between episodes → arrhythmic

Question 52

You auscultate a left sided diastolic murmur that is readily heard and of equal intensity to the S1 and S2 sounds, what grade and type of cardiac disease is this indicative of?

Answer 52

Grade 3, aortic valve regurgitation

Question 53

(T/F) Horses may have normal performance and life-span with mild to moderate valvular regurgitation.

Answer 53

T

Question 54

What three things would indicate the necessity of a cardiac work-up including echo, resting and exercise ECG?

Answer 54

Grade 3/6 murmur or higher, arrhythmias, and cardiac murmur with unexplained exercise intolerance

Question 55

What are the two predisposing conditions for endocarditis?

Answer 55

IV injection and jugular vein thrombophlebitis

Question 56

What is the most commonly endocarditis affected valve in cattle?

Answer 56

Tricuspid

Question 57

What are the most commonly endocarditis affected valves in horses?

Answer 57

Aortic and mitral

Question 58

What can occur secondary to tricuspid endocarditis or lymphoma in cattle?

Answer 58

Ruptured chordae tendineae

Question 59

What are the two causes of mitral valve ruptured chordae tendineae in horses?

Answer 59

Idiopathic or secondary to endocarditis

Question 60

What three locations can the aorta rupture into?

Answer 60

Pulmonary artery, pericardium or right of the heart

Question 61

Would the murmur associated with aortic rupture be diastolic, systolic, or continuous?

Answer 61

Continuous

Question 62

Though ventricular septal defects are typically associated with right sided systolic murmurs, they can also present with left sided systolic murmurs as a result of what two things?

Answer 62

Radiating sound or relative pulmonary stenosis

Question 63

What does the impact on lifespan and athleticism depend on with ventricular septal defects? Two answers.

Answer 63

Size of the defect and direction of the shunted blood

Question 64

What is cor pulmonale?

Answer 64

Pulmonary hypertension leading to right ventricular dilation/hypertrophy and right sided heart failure

Question 65

What is the term for the disease that is due to relatively low oxygen concentrations at high altitude leading to hypoxic vasoconstriction of the pulmonary artery as well as hyperplasia and reduced diameter of pulmonary arterioles, resulting in pulmonary hypertension?

Answer 65

Ruminant high altitude disease aka brisket or high mountain disease

Question 66

What is the treatment for high altitude disease, although prevention truly is the best strategy? Two answers.

Answer 66

Thoracocentesis to remove pleural effusion and remove to lower altitude

Question 67

What is the ideal pulmonary arterial pressure when cattle are at higher altitudes?

Answer 67

< 41 mmHg

Question 68

What should you not do with a cattle that has a pulmonary arterial pressure > 48 mmHg at higher altitudes?

Answer 68

Breed them → susceptibility is heritable

Question 69

What are the three types of pericarditis?

Answer 69

Effusive, fibrinous, and constrictive

Question 70

What is the most common cause of pericarditis in cattle?

Answer 70

Traumatic reticulopericarditis

Question 71

What is the most common cause of pericarditis in equine patients?

Answer 71

Idiopathic

Question 72

What is the suspected etiology of Actinobacillus spp. inoculation in the pericardium?

Answer 72

Ingestion of Eastern tent caterpillars

Question 73

What are the common locations for lymphoma in large animal species?

Answer 73

Right atrium, mediastinum, and pericardium

Question 74

What is the transmissible virus that causes lymphoma in cattle?

Answer 74

BLV, bovine leukemia virus

Question 75

What is the arrhythmia that is typically normal, non-pathologic in equine patients?

Answer 75

2nd degree AV block

Question 76

What are bradyarrhythmias, which are often detected in health horses, associated with?

Answer 76

High parasympathetic tone

Question 77

What is an important characteristic of non-pathologic arrhythmias in horses?

Answer 77

The are present at rest and disappear with an increase in sympathetic tone such as exercise

Question 78

What is the term for the irregularly irregular arrhythmia characterized by lack of p waves and normal, irregular QRS complexes?

Answer 78

Atrial fibrillation

Question 79

A treatment option for atrial fibrillations is administration of quinidine which is a sodium channel blocker that also affects potassium channels to have what effect on refractory period and action potential conduction?

Answer 79

Prolongs the refractory period and slows AP conduction

Question 80

(T/F) All arrhythmias are pathologic and abnormal in cattle.

Answer 80

True

Question 81

When do arrhythmias most commonly occur in cattle?

Answer 81

When the animal is off feed and/or with GI disease

Question 82

What do urinary tract obstructions or uroabdomens increase that can cause bradycardia, atrial arrest, and death in small ruminants and camelids?

Answer 82

Hyperkalemia

Question 83

What does the resulting change in excitation potentials of cardiac myocytes due to inflammation, necrosis, and/or fibrosis result in? Three answers.

Answer 83

Arrhythmias, brady/tachycardia, and poor cardiac contractility

Question 84

Nutritional myodegeneration is caused by the deficiency of what two substances/minerals?

Answer 84

Vitamin E and selenium

Question 85

What species is very susceptible to ionophore intoxication?

Answer 85

Horses

Question 86

Why are ionophores often added to livestock feed?

Answer 86

To treat coccidiosis

Question 87

Will horses with ionophore toxicity have decreased or increased left ventricular fractional shortening?

Answer 87

Poor cardiac contractility → decreased left ventricular fractional shortening