Sys/Pulm Hypertension

Question 1

What determines BP?

Answer 1

BP = CO x SVR
BP= HR x SV x SVR

Question 2

What is the main vessel controlling BP?

Answer 2

SVR: Arteriolar size controls resistance which controls pressure

Question 3

What determines blood volume?

Answer 3

Regulated through the kidneys, mainly through pressure natriuresis and RAAS

Question 4

What is the gold standard method for assessing blood pressure?

Answer 4

Arterial cath

Question 5

What measurements do doppler and oscillometric BP provide?

Answer 5

Doppler: systolic
Osc: S/D/MAP

Question 6

Secondary causes of hypertension:

Answer 6

Cats: CKD, hyperthyroid
Dogs: CKD/AKI, Cushings, diabetes, pheochromocytoma

Question 7

What is target organ damage?

Answer 7

Injury to tissues secondary to chronic, systemic hypertension
TOD is a strong indication for anti-hypertensive therapy

Question 8

What organs are affected by hypertension the most?

Answer 8

Eyes
Brain
Heart
Kidneys

Question 9

What eye lesions are seen with hypertension?

Answer 9

Hypertensive retinopathy: chronic often, hemorrhage of varying size and number
Hypertensive choroidopathy: acute often, retinal detachment, change in appearance of retinal vessels

Question 10

How do you treat hypertensive dogs?

Answer 10

1. RAAS inhibition: ACE -I, angiotensin receptor blockers, aldosterone antagonists
   (In severe cases add Amlodipine (Ca Channel blocker)

Question 11

Why dont you use calcium channel blockers as monotherapy in dogs?

Answer 11

CCBs preferentially dilate the renal affarent arteriole and can expose the glomerulus to increased glomerular capillary hydrostatic pressure
ACE-I and ARBs preferentially dialte the renal efferent so together w/ CCb have little efffect on hydrostatic pressure

Question 12

What RAAS inhibitors are used in dogs?

Answer 12

ACE-Inhibitors: benazepril, enalapril
Angiotensin II receptor blockers: telmisartan

Question 13

How do you treat hypertensive cats?

Answer 13

1. Calcium channel blockers: amlodipine
   Very good at reducing BP
2. double dose of amlodipine
3. combine amlodipine and telmisartan

Question 14

RAAS inhibitors in cats

Answer 14

Do not have the same effect in cats
ACE-I not good for pressure reduction
Angiotensin II receptor blockers: telmisartan more effectave than ACEi

Question 15

Drugs for emergency management of hypertension:

Answer 15

Hydralazine: direct arterial vasodilator
Acepromazine: non-specific vasodilator
Nitroprusside: non-specic vasodilator

Question 16

What is the normal mean pulmonary artery pressure?

Answer 16

15 mmHg

Question 17

What can pulmonary hypertension be caused by?

Answer 17

1. Increased pulmonary vascular resistance (PVR)
2. increased CO/flow
3. increased pulmonary venous pressure
   or a combo

Question 18

How does PVR decrease to accomodate increased flow/pressure during exercise or left to right shunts?

Answer 18

Capillary recruitement
Capillary distension
parallel flow reduces resistance

Question 19

Clinically significant PH is usually secondary to what?

Answer 19

Increased PVR
Pulmonary arteriolar vasoconstriction: endothelial cell dysfunction, hypoxia
Pulmonary vascular disease: obstructive lesions

Question 20

What is a sequelae from PH secondary to left heart disease?

Answer 20

Right sided HF

Question 21

Clinical recognition of PH

Answer 21

increased lung sounds: crackles
right apical systolic murmur (tricuspid regurge)
syncope
right sided heart failure

Question 22

How is PH diagnosed

Answer 22

echo