Systemic Hypertension Flashcards
Systemic Blood Pressure =
CO X SVR
Name two ways by which systemic blood pressure is regulated
Sympathetic Nervous System
Renin-Angiotensin-Aldosterone-System (RAAS)
Describe RAAS
- Initiated by hypotension
- Kidneys detect low GFR and release Renin
- Renin converts Angiotensinogen (released by liver) into Angiotensin I
- Angiotensin I converted to Angiotensin II by Angiotensin Converting Enzyme (ACE - produced by lungs)
- Angiotensin II causes vasoconstriction of all blood vessels
- Angiotensin II acts on adrenal gland to release Aldosterone
- Aldosterone stimulates reabsorption of sodium and water
Systolic BP >_______mmHg and diastolic >________mmHg is considered hypertension
160;120
T/F: Similar to humans, almost 80% of hypertension cases in cats and dogs are idiopathic.
False - Hypertension in dogs and cats is secondary in >80% of cases
By what two methods can we measure BP?
Indirect
Direct
Arterial catheterization is an example of __________ BP measurement and is the GOLD STANDARD.
Direct
Doppler and oscillometric measurement are considered indirect measurements of BP. When is one preferred over the other?
Doppler - good for cats and small dogs
Oscillometric - good for medium to large breed dogs
BP cuffs should be ________ the circumference of the chose site.
30-40%
Explain what might happen if an incorrect cuff size is chosen for a patient
If too big = falsely low BP
If too small = falsely high BP
Why is it preferred for patients to be in ventral or lateral recumbency when measuring BP?
Limit the vertical distance from the base of the heart to the cuff
Identify the mistake. You have a patient come in that you suspect is hypertensive. You rush the patient to the back and get a BP reading using an indirect method. Based on this reading, you diagnose the patient with systemic hypertension and send it home with appropriate medications.
BP measurement should be done in quiet, calm areas with the owner present. You should allow the patient to acclimate to the BP equipment prior to measuring. You’re supposed to throw out the first result and then average the next 5-7 readings.
Identify the four possible areas of TOD (Target Organ Damage)
- Eyes
- Kidney
- Brain
- Heart and vasculature
SBP >180mmHg is considered __________ hypertensive with a ________ TOD risk
Severely; high
SBP <140mmHg is considered __________ with a ________ TOD risk
Normotensive; minimal
SBP 160-179mmHg is considered ________ with a ________ TOD risk
Hypertensive; moderate
SBP 140-159mmHg is considered __________ with a ________ TOD risk
Prehypertensive; low
Ddx for secondary hypertension in cats
- CKD
- Hyperthyroidism
- Adrenal Disorders (Pheochromocytoma, Hyperaldosteronism, HAC)
- Medications
Ddx for systemic hypertension in dogs
- Kidney disease (acute and chronic)
- HAC
- DM
- Pheochromocytoma
- Hyperaldosteronism (uncommon)
Name some general guidelines for when hypertension should be treated
- Severe hypertension (>180mmHg)
- Evidence of TOD w moderate to severe hypertension
- Persistent BP >160mmHg w disease associated with hypertension
A patient’s BP measures 165mmHg, but it has no evidence of TOD. What is the best recommendation at this time?
Recheck BP in 1-2 weeks
Amlodipine is a ___________ channel blocker and is the first line of treatment in hypertensive _________
Calcium; cats
A cat comes to you with BP >180mmHg and signs of CKD. In addition to addressing the CKD, you want to start the cat on amlodipine. When would you ask the client to bring their cat back for a recheck?
7-10d is when you will start to see the max effect
If patient is still hypertensive or hypotensive, the dose can be altered
Name some ACE inhibitors
Benazepril
Enalapril
