Hypertension and RAAS Flashcards
How and when should BP be measured in a dog/cat during a visit?
In a quiet area, away from other animals, before other procedures, and after the patient has acclimated for 5-10 minutes. Owner should be present and restraint should be minimal, but the patient should be in ventral or lateral recumbency
What should the width of the BP cuff be?
30-40% of the circumference of the extremity at the site of cuff placement
How many BP measurements should be obtained?
Discard the first measurement. Then 5-7 consecutive, consistent readings
If BP is trending downward as the animal adjusts, continue until a plateau is reached, then take 5-7 readings
If the vertical distance from the heart to the base of the cuff is more than 10cm, what correction can be applied?
Add 0.8 mmHg/cm below or above the heart base
Blood pressure in hounds (Greyhounds, Deerhounds) is how much higher than other dogs?
10-20mmHg higher
What is situational hypertension?
Increases in BP that occur as a consequence of the in clinic measurement process in an otherwise normotensive animal
What causes situation hypertension?
Autonomic nervous system alterations
What is secondary hypertension?
Persistent, pathologically increased BP concurrent with a disease or condition known to cause hypertension or administration of a drug or toxin known to cause hypertension
Name 6 disease conditions associated with secondary hypertension
CKD, AKI, hyperadrenocorticism, DM, primary hyperaldosteronism, pheochromocytoma, hyperthyroidism
Name 5 drugs associated with secondary hypertension
Glucocorticoids, mineralocorticoids, EPO, PPA, Ephedrine/pseudoephedrine, Palladia
What is primary/essential/idiopathic hypertension?
Persistent, pathological hypertension in the absence of any identifiable underlying cause
How can BP affect USG?
Hypertension can cause polyuria from pressure diuresis, so a USG <1.030 in a patient with hypertension does not necessarily mean that CKD is present
What percent of cats have idiopathic hypertension?
13-20%
How can hypertension affect the kidneys?
Causes proteinuria and histological renal injury. Proteinuria, in turn, leads to more rapid progression of renal disease
What are the findings with hypertensive retinopathy and choroidopathy?
Exudative retinal detachment - most common
Retinal hemorrhage or edema, retinal vessel tortuosity, vitreal hemorrhage, hyphema, secondary glaucoma, and retinal degeneration
What is hypertensive encephalopathy?
White matter edema and vascular lesions from hypertension
When is hypertensive encephalopathy more likely to occur?
Cats with a sudden increase in BP, systolic BP >180 mmHg, or both
What are the clinical signs of hypertensive encephalopathy?
Lethargy, seizures, acute onset of altered mentation, altered behavior, disorientation, vestibular signs
Hypertension is also a risk factor for ischemic myelopathy of the cranial cervial spinal cord. How does this present?
Cats with ambulatory tetraparesis or tetraplegia with intact nociception
What is the most common cardiac change associated with hypertensive cardiomyopathy?
Left ventricular concentric hypertrophy
What are the indications for measuring BP in a dog or cat?
- Patients with clinical abnormalities consistent with hypertensive target organ damage
- The presence of diseases or conditions or the treatment with drugs associated with secondary hypertension
In the majority of cases, BP results should be repeated on >2 occasions before starting treatment. What is the exception?
When there is evidence of target organ damage along with an elevated BP - start treatment now
What are the classifications of hypertension in dogs/cats?
Normotensive: SBP < 140
Prehypertensive: SBP 140-159
Hypertensive: SBP 160-179
Severely hypertensive: SBP >180
If a patient’s BP is <160 mmHg, when should they be rechecked?
3-6 months
