Hypertension Flashcards
What is hypertension?
https://www.youtube.com/watch?v=9CKihqqIokI&vl=en-US
The blood pressure above which the benefits of treatment outweigh the risks in terms of morbidity and mortality.
What are risk factors for the development of hypertension?
- Cigarette smoking (adds 20/10 mmHg)
- Diabetes Mellitus (5-30x increased risk of MI)
- Renal Disease
- Male
- Hyperlipidaemia
- Previous MI or Stroke
- LVH
- Family history
- Low birth weight
What are the different types of hypertension?
- Primary/Essential hypertension
- Secondary hypertension
- Malignant hypertension
- White coat hypertension
What is primary hypertension?
This is hypertension of unknown cause. It accounts for the vast majority (> 95%) of cases. In these cases, hypertension is due to a combination of genetic, lifestyle and environmental factors.
What is secondary hypertension?
Present when blood pressure is raised due to an identifiable and potentially treatable cause; examples include renal, renovascular and endocrine disorders, certain drugs (such as steroids or the oral contraceptive pill), coarctation of the aorta and pregnancy.
What is malignant hypertension?
An acute rise in blood pressure (usually to > 180/110mmHg) with papilloedema (optic disc swelling) and/or retinal haemorrhage. Malignant hypertension is a medical emergency and may be associated with heart failure, cerebral oedema and renal failure.
What is white coat hypertension?
Present when blood pressure is normal other than when checked during a medical consultation; 24-hour blood pressure monitoring may help decide whether the patient is truly hypertensive.
What is benign hypertension?
Any stage 1 or stage 2 hypertension
What are the criteria for stage 1 hypertension?
Clinic blood pressure = 140/90 mmHg or higher
+
ABPM or HBPM average BP = 135/85 mmHg or higher.
What are the criteria for the diagnosis of stage 2 hypertension?
Clinic blood pressure = 160/100 mmHg or higher
+
ABPM or HBPM average BP = 150/95 mmHg or higher
What are the criteria for the diagnosis of severe/Stage 3 hypertension?
Clinic systolic blood pressure = 180 mmHg or higher
Clinic diastolic blood pressure = 110 mmHg or higher
What factors play a role in the development of primary hypertension?
- Genetic
- Age
- Foetal factors
- Obesity
- Alcohol intake
- Sodium intake
- Stress
- Humoral mechanisms
- Insulin resistance
- Race
Why does age play a role in the development of hypertension?
Reduced arterial compliance
What foetal factors play a role in the development of hypertension?
Low birth weight
How does sodium intake influence blood pressure?
Sodium acts osmotically to pull more fluid into the vascular space
What are cardivascular causes of secondary hypertension?
Coarctation of the Aorta
What condition in pregnancy can cause secondary hypertension?
Pre-eclampsia
What are endocrine causes of secondary hypertension?
- Cushing’s syndrome
- Acromegaly
- Thyroid disease
- Hyperparathyroid disease
- Conn’s syndrome
- Phaeochromocytoma
- Adrenal hyperplasia
What are adrenal causes of hypertension?
- Conn’s syndrome
- Adrenal hyperplasia
- Phaeochromocytoma
What are renal causes of secondary hypertension?
- Diabetic nephropathy
- Chronic GN
- Adult Polycystic disease
- Chronic tubulointersitial nephritis
- Renovascular disease
What drugs can cause secondary hypertension?
- NSAIDs
- MAOIs
- Oral contraceptives
- Vasopressin
- Sympathomimetics
What respiratory problems can cause secondary hypertension?
Sleep apnoea
What are the features of hypertensive retinopathy?
- AV nipping
- Copper and Silver wiring
- Cotton wool spots
- Microaneurysms
- Retinal haemorrhages
What is the following?
AV nipping - An enlarged retinal arteriole that crosses a vein can press down and cause swelling distal to the crossing. The vein will have an hourglass appearance on either side of the intersection.
What is the following and what is it a sign of?
Cotton wool spots - Small areas of yellow-white discolouration on the retina, often described as puffy white patches.
Diabetes and hypertension
What is the following, and what is it a sign of?
Retinal haemorrhage - Bleeding that occurs in or spills onto the retina. Can be ‘dot and blot’ or ‘streaking’ in appearance.
Sign of diabetes, hypertension or trauma
What are retinal microaneurysms?
Small, round, dark red dots on the retinal surface that are smaller than the diameter of major optic veins They often herald a progression to the exudative phase of hypertensive retinopathy.
As progression of hypertensive retinopathy occurs, there is capillary occlusion ischaemia and degeneration of the vascular smooth muscle, endothelial cell necrosis and formation of tiny aneurysms.
What is the mechanism behind the following?
AV nipping - Persistently elevated blood pressure causes hyperplasia of the arteriolar media and intimal thickening. The enlarged vessel impinges on the underlying vein, giving it a ‘nipped in’ appearance.
What is the mechanism behind the following?
Cotton wool spots - Principally due to damage and swelling of the nerve fibres. Prolonged hypertension results in distortion and blocking of retinal arterioles, blockage of axoplasmic flow (of proteins, lipids etc along the axon of the neuron) and a build-up of intracellular nerve debris in the nerve fibre layer. These insults result in swelling of the layer.
What is the mechanism of the following?
Retinal haemorrhage - Prolonged hypertension leads to intimal thickening and ischaemia. This causes degeneration of retinal blood vessels to the point where they leak plasma and bleed onto the retina.
What are features of end organ damage in hypertension?
- Blindness - hypertensive retinopathy
- Cardiac failure - LVH, MI, Pulmonary oedema
- Vascular disease - Atherosclerosis/Aneurysms/Dissections
- CKD - proteinuria, uraemia
- Stroke/TIA - Haemorrhage, seizure, Vascular dementia
What signs would indicate that coarctation of the Aorta could be causing hypertension?
- Radio-femoral delay
- Radial-radial delay
- Hypertension
- Scapular bruit
- Systolic murmur - over scapula
What is the mechanism behind the sign of radiofermoral delay?
Reduced amplitude and delayed timing of the pulses in the lower body with respect to the pulses in the upper body are classic features of aortic coarctation
Coarctation causes a decrease in the rate of ejection of blood because of vessel narrowing and the Venturi effect sucking the walls inwards, creating a reduction in the flow and amplitude of the pulse distal to the occlusion.
What is the mechanism behind radial-radial delay?
A disparity between the timing of pulses felt when simultaneously palpating the left and right radial pulse.
A coarctation or narrowing of the aorta occurs before the origin of the left subclavian artery, limiting the blood flow and causing a pressure drop distal to the narrowing. The pulse wave will arrive later in the left arm and the amplitudes of the left and right pulses will be different.
What features on ECG would indicate LVH?
- Increase in QRS amplitude
- Left atrial enlargement.
- Left axis deviation.
- ST elevation in V1-3 - discordant to the deep S waves
- Prominent U waves - proportional to increased QRS amplitude
Why are young people (<55) better to be started on ACEi or ARBs rather than CCBs or thiazide diuretics?
Young hypertension is likely to high renin hypertension, therefore ACEi are most appropriate
Why are the elderly (>55) and black patients started on CCBs or thiazide diuretics?
They are more likely to have low renin hypertension
What tests would you do to confirm hypertension?
Clinic BP, then if high, ambulatory blood pressure monitoring
How would you investgate suspected high blood pressure?
- Confirm high blood pressure
- Quantify risk
- Tests for end organ damage
- Tests for secondary causes
How would you quantify risk in someone with hypertension?
- Fasting glucose
- Cholesterol levels
How would you assess for end organ damage?
- ECG - LVH, previous MI
- Urine dipstick - protein, blood
- Opthalmoscopy - hypertensive changes
- ECHO - LVH
How would you investigate for secondary causes of hypertension?
- Bloods - U+Es, Ca2+, renin and aldosterone levels
- Renal ultrasound/arteriography
- Urinary free cortisol
- MRI aorta
- Urinary metanephrines/catecholamines
Why would you look at U+E’s and creatinine clearence when investgating for secondary causes of hypertension?
- Polycystic disease
- Renal arterial disease
- Low K+ - Conn’s syndrome, Cushing’s
What might low K+ indicate when investigating for secondary causes of hypertension?
Conn’s or Cushing’s syndrome
Why would you do a renal ultrasound as part of investigations for secondary causes of hypertension?
To look for signs fo Renal artery stenosis
Why would you look at urinary metanephrines/catecholamines when investigating for secondary causes of hypertension?
Look for Phaeochromocytoma
Why would you look at serum renin, aldosterone and cortisol when investgating hypertension?
Looking for conn’s or cushings syndrome
Why would you perform an MRI scan of the aorta when investigating for secondary causes of hypertension?
Coarctation of the aorta
What are the features of grade I hypertensive retinopathy?
Copper and silver wiring - Tortuous arteries with thick shiny walls. Retinal arterioles appear orange or yellow instead of red (“copper wiring”) Retinal arterioles look white if they have become occluded (“silver wiring”)
What are the features of grade II hypertensive retinopathy?
A-V nipping
What are the features of grade III hypertensive retinopathy?
Retinal haemorrhages and cotton wool spots
What are the features of grade IV hypertensive retinopathy?
Papilloedema
What is the following and what can it indicate?
Papilloedema - is swelling and blurring of the optic disc margins.
Can indicate malignant hypertension
What is the mechanism behind the following?
Papilloedema - caused by increased intracranial pressure or a compression lesion of the optic nerve. Disc swelling papilloedema results from blockage of axoplasmic flow in neurons of the optic nerve, resulting in swelling of the axoplasm of the optic disc. Papilloedema is associated with other signs of optic nerve dysfunction (e.g. decreased visual acuity, relative afferent pupillary defect [RAPD], monocular vision loss).
The most common visual defects in acute papilloedema are enlargement of the physiological blind spot, concentric constriction and inferior nasal field loss
If someone had a ABPM of <130/85, how would you manage them?
Reasses in 5 years
If someone had an ABPM of between 130-139/85-89, how would you manage them?
Reassess yearly
If someone was diagnosed with stage 1 hypertension, how would you manage them?
Assess risk and presence of end organ damage
<80 years, ABPM >135/85, plus one or more of:
- Target organ damage
- Established CVD
- Renal Disease
- Diabetes
- 10 year CV risk >= 20%
TREAT THEM
If someone had stage II hypertension, how would you manage them?
Treat
If you were starting someone on antihypertensive medication, what would you want to determine first?
Age - > 55 years
What are the general components to the overall management of hypertension?
- Lifestyle changes
- Medication
What lifestyle changes would you advise someone with hypertension?
- Stop smoking
- Low fat diet
- Reduce alcohol
- Reduce sodium intake
- Increase exercise
- Reduce weight
What would you start someone on for treatment of hypertension if they were under 55 (step 1 of NICE guidelines)?
ACEi, although if child bearing age in females, CCB or B-blocker
What would you start someone on for hypertension if they were over the age of 55 (step 1 of NICE guidelines)?
CCB (1st choice) or Thiazide diuretic
What medications would you add at step 2 of the treatment of hypertension (according to NICE guidelines)?
<55 years - add CCB or Thiazide Diuretic
or
>55 years - add ACEi
What medications would you add as part of step 3 of the NICE guidelines for treatment of hypertension?
<55 years - add either CCB or Thiazide (depending on which has not been added)
or
>55 years - add either CCB or Thiazide (depending on which has not been added)
Treatment for both should be ACEi, CCB and Thiazide together at this stage
What medications would you add as part of Step 4 of the NICE guidelines for treating hypertension?
Consider spcialist advice
Add B-blocker (1st choice), or alpha blocker or further diuretic treatment (spironolactone)
In someone with resistant hypertension, what further diuretic therapy would you consider using?
Spironolactone
Higher dose thiazide diuretics
When treating someone with resistant hypertension, when would you consider using spironolactone as a therapy?
If the blood potassium level is 4.5 mmol/l or lower
When treating resistant hypertension, when would you consider using higher dose thiazide diuretics?
if K+ > 4.5 mmol/L
What are the different types of hypertension that can occur in pregnancy?
- Chronic/pre-existing hypertension
- Gestational hypertension
- Pre-eclampsia
What medications can you use pre-pregnancy for hypertension?
- Nifedipine
- Methyldopa
- Atenalol
- Labetalol
What treatments would you add to treatment for hypertension during pregnancy?
Thiazide diuretic +/- amlodipine
When would you use ARB’s instead of ACEi?
When someone is expriencing a cough due to ACEi - 1 in 10 get this problem
What type of CCBs are used in hypertension?
Dihydropyridines are CCB of choice
What is hypertensive encephalopathy?
General brain dysfunction due to significantly high blood pressure - caused by cerebral oedema secondary to loss of cerebral autoregulation
How does hypertensive encephalopathy manifest?
- Headache
- Nausea
- Vomiting
- Confusion
- Grade III/IV hypertensive retinopathy
- Late signs - fits, coma, neuro signs
What is the defintion of hypertensive crisis?
Defined as severe elevation in BP (SBP > 200mmHg, DBP > 120mmHg)
What are the different classificaitons of hypertensive crises?
- Hypertensive emergency
- Hypertensive urgency
What are the subtypes of hypertensive emergencies?
- Hypertensive emergency with retinopathy - DBP > 140 mmHg + retinal haemorrhage and exudate
- Hypertensive emergency with pailloedema - similar BP but with papilloedema (previously malignant hypertension)
What is the difference between hypertensive emergency and hypertensive urgency?
Emergency there is HTN + end organ damage, whereas urgency there is similar rise in BP, but no end organ damage
What endocrine disorders can present with hypertensive emergencies?
- Phaeochromocytoma
- Cushing’s
- Primary hyperaldosteronism
- Thyrotoxicosis
- Hyperparathyroidism
- Acromegaly
- Adrenal carcinoma
What conditions may present with hypertensive emergencies?
- Essential HTN
- Renovascular HTN
- Renal parenchymal disease
- Endocrine disorders
- Eclampsia and pre-eclampsia
- Vasculitis
- Drugs
- Spinal cord injury
- Coarctation of Aorta
What are renovascular causes of hypertensive emergency?
- Atheroma
- Fibromuscular dysplasia
- Acute renal occlusion
What renal parenchymal disorders can present with hypertensive emergencies?
- Acute GN
- Vasculitis
- Scleroderma
What mnemonic can you use to think of causes of secondary hypertension?
ABCDEF
- Apnea, Acromegaly,
- Birth control, Bad kidney
- Coarctation of the aorta, Cushing’s, Conn’s, Catecholamines
- Drugs (alcohol, nasal decongestants, estrogens)
- Endocrine disorders, Erythropoietin
- Fibromuscular dysplasia
What investigations/monitoring should you perform if starting someone on durgs for resistant hypertension?
Monitor blood sodium and potassium and renal function within 1 month and repeat as required thereafter.
