Hypertension Flashcards
Recall the stages of hypertension as well as their corresponding systolic parameters
- Grade 1 - 140-159
- Grade 2 - 160-179
- Grade 3 - >180
What is the main risk of Grade 3 hypertension?
Risk of precipitating malignant hypertension
What blood pressure parameters are characteristic of hypertensive urgency?
Systolic BP > 180 or diastolic BP > 110
Suggest 4 clinical symptoms that can be associated with hypertensive urgency
- Epistaxis
- Headache
- SOB
- Severe anxiety
What is the difference between hypertensive urgency and a hypertensive emergency?
There is no end organ damage in hypertensive urgency
Suggest 6 symptoms that can be associated with malignant hypertension
- Chest pain
- SOB
- Back pain
- Numbness/weakness
- Visual changes
- Difficulty speaking
What is the pathophysiology of encephalopathy in malignant hypertension?
Elevate cerebral BP leads to cerebral oedema and in turn raised ICP
What is the ‘QRISK’ calculator used for?
To estimate a patient’s 10 year risk of developing cardiovascular disease
Recall the equation used for calculating cardiac output
CO = HR * SV
Recall the equation that relates cardiac output and BP
BP = CO * PR
Where in the body is angiotensinogen synthesised?
Liver
What are the 2 main biochemical consequences of the release of Renin by the kidneys in response to a reduction in blood flow?
- Conversion of angiotensinogen into angiotensin I
2. Induces secretion of aldosterone
What are principle biochemical effects of aldosterone release?
Increased sodium and water reabsorption
Outline the 3 main components of the body’s short term response to changes in blood pressure
- Central nervous system response
- Baroreceptors
- Chemoreceptors
From which sections of the spine to sympathetic vasomotor nerve fibres leave the spinal cord?
Thoracic and lumber spine
Which vasomotor nerve fibres originate from the vasoconstrictor area?
Excitatory preganglionic vasoconstrictor neurons
What is the function of the vasodilatory area of the brainstem?
Internal inhibition of the vasoconstrictor area
The sensory component of the vasomotor area of the brainstem is supplied by which 2 cranial nerves?
- Vagus
2. Glossopharyngeal
Name 4 brain structures that influence the vasomotor centre
- Reticular substance
- Hypothalamus
- Cerebral cortex
- Cingulate gyrus
Define myogenic tone
State of muscle tone from the muscle itself i.e. not mediated by the autonomic nervous system or a reaction to a hormonal process
Compare the effects of activation of beta adrenoreceptors in the heart and in the peripheral vasculature respectively
- Heart - increased contractility
2. Peripheral vasculature - reduced contractility
Why is dobutamine used in the treatment of heart failure patients?
Preferential beta1-adrenoreceptor agonist, thereby increasing cardiac contractility more effectively than pan adrenoreceptor agonists such as adrenaline
Describe the conduction pathway between the carotid baroreceptors and the brainstem
Hering’s nerve –> Glossopharyngeal nerve –> Tractus solitarius in the brainstem
What is the consequence of arterial baroreceptors detecting an abnormal increase in blood pressure?
Stimulation of the tracts solitarius leads to inhibition of the vasoconstrictor centre and excitation of the vagal parasympathetic centre
What happens in the atrial volume reflex?
- Atrial stretching due to increased systemic BP leads to reflex dilation of renal afferent arterioles, thus increasing glomerular capillary pressure and increasing the rate of fluid filtration into the renal tubule.
- Also leads to reduced secretion of ADH from the hypothalamus
What are the 2 components of long term control of BP
- Renin-aldosterone-angiotensin system
2. Vascular remodelling and contractility
Name the 3 cellular components of the juxtaglomerular apparatus
- Macula densa
- Juxtaglomerular cells
- Extraglomerular mesangial cells
Which cell type allows connection between the glomerular arterioles and the distal convoluted tubule?
The extraglomerular mesangial cells as part of the juxtaglomerular apparatus
What are the 5 main actions of angiotensin II
- Increased sympathetic activity
- Increased reabsorption of Na and water + increased excretion of K
- Stimulates the release of aldosterone from the adrenal cortex
- Arteriolar vasoconstriction
- Increased secretion of ADH from the posterior pituitary
Name the 3 sections of the renal tubule that aldosterone acts on to increase absorption of Na +and excretion of K + and H +
- Principle cells of the collecting tubules
- Distal tubules
- Collecting ducts
Which biochemical imbalance is associated with primary hyperaldosteronism?
Hypokalaemic Alkalosis
Outline the 2 main causes of primary hyperaldosteronism
- Unilateral aldosterone producing adenoma
2. Bilateral adrenal hyperplasia
What is synacthen?
Synthetic ACTH used in the diagnosis of Addison’s disease
What is the systemic effects of adiponectin released by adipose tissue? (3)
- Glucose regulation
- Fatty acid breakdown
- Dilation of small arteries
Name 3 renal diseases that can cause secondary hypertension
- Polycystic kidney disease
- Glomerular disease
- Renovascular disease
Name 3 adrenal conditions that can cause secondary hypertension
- Cushing’s syndrome
- Primary aldosteronism
- Phaeochromocytoma
Name 5 drug types that can cause secondary hypertension
- Oral contraceptives
- NSAIDS
- Stimulants (cocaine, methylphenidate)
- Calcineurin inhibitors
- Antidepressants
