Hypertension Cards Flashcards
What is hypertension?
High blood pressure (pressure on blood vessels).
Hypertension is ______ cardiovascular disease.
Hypertension is the most common cardiovascular disease
What percent of Canadian adults are diagnosed with hypertension?
23% of canadian adults have hypertension
Risk factors of hypertension include… (4)
Genetic factors, environmental factors, stress, diet
Hypertension can cause…
blood vessel damage, renal failure, heart disease, strokes
Treatment for hypertension will…
slow blood vessel damage, decrease morbidity and mortality
What is the equation for blood pressure?
BP = CO x PVR
BP - blood pressure
CO - cardiac output
PVR - peripheral vascular resistance
The 4 main players in blood pressure control are…
arteries, veins, the heart, and the kidneys.
The arteries control blood pressure by…
controlling resistance of blood out of the heart
Veins control blood pressure by
acting as a capacity to return blood
(veins can expand to hold more blood)
The heart controls blood pressure by…
cardiac output and cardiac rate
(rate of beats and volume moved)
Kidneys control blood pressure by…
Directly influencing the volume of blood in the body
Baroreceptors are responsible for?
Regulation of blood pressure on a short-term basis.
Baroreceptors are found in the _____ and ____.
found in the carotid artery and aorta
Baroreceptors monitor BP by monitoring the “___” of blood vessels.
the stretch.
Increased stretch of blood vessels leads to…
Increased baroreceptor firing
Decreased stretch of blood vessels leads to…
decreased baroreceptor firing
In order to raise blood pressure, baroreceptors will stimulate the ___ and reduce activity in the ___
Stimulate the Sympathetic NS and reduce PSNS activity
In order to lower blood pressure, baroreceptors will stimulate the ___ and reduce activity in the ___
stimulate the PSNS and reduce activity in the SNS
Increased SNS activity…
typically raises heart rate
Increased PSNS activity…
usually lowers heart rate.
The kidney controls __-__ blood pressure.
The kidney controls long term blood pressure
How do the kidneys control blood pressure?
Through blood volume and vascular tone
When blood pressure in the renal arteries drops, the kidneys begin to produce ___
The kidneys produce renin when blood pressure drops.
What does renin do?
Renin is an enzyme which converts angiotensinogen into angiotensin 1 which is further converted to angiotensin 2 by ACE.
What are the steps which turn angiotensinogen into angiotensin II?
Angiotensinogen -> angiotensin I (catalyzed by renin released from kidneys )
Angiotensin I -> Angiotensin II (catalyzed by ACE)
What is ACE (kidney blood pressure enzyme)
ACE is the angiotensin-converting enzyme which converts Angiotensin I -> Angiotensin II
Renin production can be stimulated by ___ or ___
Renal arterial pressure decrease or SNS stimulation of B1 receptors in the kidneys can produce renin.
*This makes sense because SNS stimulation typically raises blood pressure
What is aldosterone?
Aldosterone is a hormone secreted by the adrenal gland. It is released in the presence of Angiotensin II
What does aldosterone do?
Aldosterone increases sodium retention and water retention in the kidneys. This increases blood volume.
What is the ideal blood pressure?
90 - 120 over 60 - 80
90-120/60-79
What is a pre-hypertensive blood pressure?
120-130/60-79
What are stage 1 and stage 2 hypertension BPs?
Stage 1: 130-139/80-89
Stage 2: 140/90 or higher
What are the goals of antihypertensive therapy?
- Decrease blood pressure to prevent organ damage
- Balance between risk of drug toxicity and not treating the issue
- done through monotherapy or combined therapy
In the central nervous system, ___ neurons regulate BP
adrenergic neurons regulate blood pressure in the CNS
Stimulating alpha 2 receptors in the CNS will ____ NE release.
alpha 2 receptors are generally inhibitory receptors. So NE release is reduced.
What are sympatholytics?
Drugs that act on, and reduce activity in the sympathetic nervous system.
What is an example of a centrally acting sympatholytic?
Clonidine is an Alpha 2 agonist which will reduce NE in the CNS, this reduces SNS activity which will reduce blood pressure.
What are the adverse effects of using centrally-acting sympatholytics?
alpha 2 agonists in the CNS can cause bradycardia, constipation, and sedation/impaired concentration.
What are peripherally acting sympatholytics?
Beta-blockers and alpha-blockers.
What are the 2 beta blocker peripheral sympatholytics?
Propanolol (non-selective) and Metoprolol (selective beta 1)
How does blocking b1 receptors influence blood pressure?
Blocking b1 receptors in the heart reduces cardiac output (CO) which reduces BP
Blocking b1 receptors in the Juxta-glomerular region of the kidneys reduces renin release.
What are the toxicities associated with beta-blockers used to treat hypertension?
Bradycardia, due to b1 antagonism
All side effects associated with b2 antagonism (when non-selective b1 blockers (propranolol) are used)
All vasodilators ____, some also ___.
All vasodilators relax arterial smooth muscle, some also relax venous smooth muscle.
What’s the main caveat of vasodilators?
Baroreceptors and the renin-angiotensin system will compensate for the effects.
Due to the compensatory effects of BRs and the renin-angiotensin system…
vasodilators work best when paired with an additional anti-hypertensive medication which oppose those systems.
Sodium nitroprusside dilates arterial and venous vessels by…
Diffusing NO into endothelial cells which leads to increased production of cGMP which causes muscle relaxation.
Sodium nitroprusside is given ___ for ____ because it is _____
Sodium nitroprusside is given IV for emergencies because it is “short-acting”
Verapamil is a vasodilator which inhibits ____.
Verapamil is a vasodilator which inhibits Ca+2 influx into arterial smooth muscle, leading to muscle relaxation.
What is the issue with verapamil?
It also inhibits cardiac Ca2+ channels leading to bradycardia
What does aldosterone do?
It increases NA+ reabsorption in the distal tubule and collecting tubule (Water follows salt)
What are the 2 angiotensin inhibitors?
Enalapril and Losartan
What is enalapril?
Enalapril inhibits the ACE enzyme. This prevents the conversion of Angiotensin I to Angiotensin II.
What are the side effects of Enalapril?
Cough, hypotension, hyperkalemia, dizziness, headache
What is Losartan?
Losartan is an ARB, an angiotensin receptor blocker. Prevents the binding of angiotensin II which increases blood pressure.
What are the side effects of Losartan?
Same as Enalapril without the cough
hypotension, hyperkalemia, dizziness, headache
What are diuretics?
Diuretics reduce blood pressure.
Diuretics prevent fluid buildup in the body (they make you pee by depleting Na+ levels.
What is hydrochlorothiazide?
Hydrochlorothiazide is a medium potency diuretic. It can be used to cure mild-moderate hypertension
What is Furosemide?
Furosemide is a powerful diuretic, it can be used to cure severe hypertension either alone or with a sympatholytic and vasodilator.
____ inhibitors enhance the effect of diuretics
ACE inhibitors enhance diuretics.
Angiotensin II stimulates aldosterone which promotes NA+ and Water reabsorption.
Specifics of hydrochlorothiazide.
Hydrochlorothiazide is a thiazide diuretic
Absorbs well orally, is cheap and effective.
What are the toxicities of hydrochlorothiazide?
Hypokalemia (potassium deficiency), gout, hyponatremia (dehydration)
Hypokalemia is bad for people suffering from arrhythmias, acute myocardial infarction (heart attack), and people taking digitalis
Digitalis is a medication which influences heart rhythm.
Specifics of furosemide
Furosemide is a loop diuretic, meaning it prevents NaCl reabsorption in the loop of Henle
Rapid and short-acting, it is usually used for severe hypertension and pulmonary edema (fluid in lungs)
What are the toxicities of furosemide?
Same as the toxicities of thiazide diuretics but can also cause dose-dependent ototoxicity (hearing loss)
- Hypokalemia, gout, hyponatremia
What are some non-medical treatments for hypertension?
Low salt diet, weight loss, exercise.
Initial monotherapy for hypertension often looks like…
- A thiazide diuretic if mild or moderate
- ACE inhibitors or ARBs
3.Ca2+ channel blockers - Beta-blockers
- Alpha-blockers
Monotherapy is better because it is…
Simple, more compliance, low incidence of toxicity
Stepped therapy is used when…
Hypertension is more severe or cant be treated with one drug.
Drugs are added in a stepwise fashion until optimal BP reached.
What is the treatment order of combination/stepped therapy for hypertension?
- Lifestyle changes
- diuretics
- ACE inhibitor/ARB
- Calcium channel blocker
- Sympathilytics/vasodilators
What is the problem with combination therapy?
Patient compliance is low due to price, number of meds, and side effects.
How is patient compliance with hypertension therapy raised?
Fixed-dose combinations are available.
These increase compliance but we can’t titrate individual drug doses.
