Hypertension Flashcards
Causes of secondary HTN
- Renovascular Disease/Renovascular
- Primary renal disease – eGFR + UA
- Polycystic Kidney Disease
- Endocrine causes such as:
○ Cushing’s Syndrome (primary pituitary adenoma or secondary due to drugs)
○ Conn’s Syndrome (primary hyperaldosteronism)
○ Pheochromocytoma (catecholamine-secreting adrenal tumour which causes triad of headache, palpitations, sweating)
○ Hyperthyroidism
○ Hyperparathyroidism - Coarctation of the aorta: hypertension in the upper extremities, brachial-femoral delay, low/unobtainable BP in the lower extremities
- Medications
○ Glucocorticoids
○ Contraceptives
○ NSAIDs
○ Antidepressants
○ Calcineurin inhibitors: Cyclosporin, tacrolimus
○ EPO - OSA - Sleep Study
Aldosterone:Renin Ratio
Aldosterone:Renin Ratio (ARR) is used to detect primary hyperaldosteronism in high risk, hypertensive patients
Aldosterone:Renin Ratio (ARR) • Primary Hyperaldosteronism – renin supressed; ratio increased >20 • Secondary Hyperaldosteronism – both are increased and decreased ratio (<10) ○ Renovascular disease ○ Diuretic therapy ○ Renin secreting tumour ○ Malignant hypertension ○ Coarctation of the aorta • Both supressed (non aldosterone mineralocorticoid excess): ○ Congenital adrenal hyperplasia ○ Exogenous mineralcorticoid ○ Cushing's syndrome ○ Liddle syndrome ○ Glucocorticoid resistance
Causes of renal artery stenosis
Most common
(A) Atherosclerotic disease 60-80%
Typically affects ostial/proximal portion of renal artery, can occur bilaterally
(B) Fibromuscular dysplasia 10-20%
- Non-atheromatous, non-inflammatory vascular condition
- Typically affects mid to distal renal artery, characteristic “string of beads” appearance on CTA
- Smoking, pregnancy associated with increased risk
- Renal arteries involved in 75 to 80% and extracranial cerebrovascular arteries (e.g., carotid and vertebral arteries) in 75 %
- Approximately two-thirds of patients have multiple arteries involved
Other Causes
- Renal artery embolism
- Dissection/thrombosis
- Post traumatic injury
- Occlusion from aortic stent graft
- External compression
- Systemic vasculitis
Atherosclerotic vs Fibromuscular Dysplasia RAS
Atherosclerotic RAS - Men: Women = 1:1 - Age > 55yo - Ostial/proximal renal artery - Ischaemic atrophy common - Total occlusion can occur - Less amenable to intervention RAS: Usually after 50 years and cholesterol plaque obstructs renal artery ( lesions usually within 2 cms of origin from aorta)
Fibromuscular Dysplasia - Women more affected (3:1 ratio to men) - Typical age 30-50, - Mid to distal renal artery - Ischaemic atrophy rare - Total occlusion rate - Amenable to intervention: good cure rates for HTN FMD: Commoner in women below 50 years age and unrelated to lipid status (lesions distal to proximal 2 cms of aortic origin of renal artery)
Difference between unilateral and bilateral renal artery stenosis
Unilateral Renal Artery Stenosis
- Increased BP
- Increased renin
- Normal volume state
Bilateral Renal Artery Stenosis
- Increased BP
- Normal renin
- Increased volume state
What is the pickering syndrome
Overtime, bilateral renal artery stenosis with volume overload leads to diastolic dysfunction and flash pulmonary oedema
When to suspect renovascular disease?
- Age of onset hypertension <30yrs or >55yrs
- Abrupt onset of hypertension
- Acceleration of previously stable blood pressure
- Hypertension refractory to appropriate 3-‐drug regimen
- Malignant hypertension
- Accelerated retinopathy
- Flash pulmonary oedema
- AKI with ACEI treatment
- Abnormal circadian rhythm with loss of nocturnal pressure fall
Consider in: – Young pts with HT – Severe or refractory HT – Increased Cr with ACE-I or ARB – Flash pulmonary oedema (more common with bilat RAS) – Known vascular disease and HT
• Rise in the serum creatinine by > 30 % within week of starting ACEI or ARB
• Severe hypertension in a patient with an unexplained atrophic kidney or
asymmetry in renal sizes of >1.5 cm
• Onset of severe and usually rapid hypertension after the age of 55
• A systolic-diastolic abdominal bruit that lateralizes to one side: low sensitivity (40 %) but very high specificity (99 %)
• Recurrent presentations with flash pulmonary oedema and refractory heart failure
• Keeps getting echocardiograms…troponins…diuresis…..keeps coming
back…..
• Please think about bilateral renal artery stenosis
What are other causes of elevated renin
- 15‐20% of people with essential hypertension will have elevated renin
- Renin can also be elevated with oestrogen intake, pregnancy, cortisol excess, from intra‐renal parenchymal disease, etc
- Renin levels fluctuate with posture, sympathetic tone, sodium intake and with the use of other drugs
Investigations for renovascular disease
- Renin, aldosterone levels
- Conventional angiography: gold standard
○ Generally reserved for confirmation and can proceed to subsequent intervention if required
○ Risks: AKI, cholesterol embolisation, contrast induced nephropathy, dissection, perinephric/groin haematoma - CT angiogram:
○ Most sensitive test, good pictures - Highly sensitive for FMD
○ Beware contrast load with renal impairment - MRI/A
Less sensitive for FMD - Doppler US
• velocity 3x the feeding artery significant
• Resistive indices: If >0.8 predicts poor outcome with angioplasty
Management of renovascular htn
- Blood pressure management with ACE/ARB
- Aggressive CVS risk factor modification
- Angioplasty + stenting - well established for fibromuscular dysplasia
Most patients with Conn’s Syndrome (primary hyperaldosteronism) present with? A. Hypertension and hyperkalaemia B. Hypertension and hypokalaemia C. Hypertension and normokalaemia D. Other irrelevant answer A E. Other irrelevant answer B
C. Hypertension and normokalaemia
Primary Aldosteronism
• Hypokalaemia and metabolic alkalosis (potassium normal in > 50% cases)
Treatment for renal artery stenosis
Unilateral RAS
- Medical therapy with ACE-I or ARB +/-thiazide
- Angioplasty for FMD
Bilateral RAS
- Traditionally avoid ACE-I or ARBs due to theoretical A-II dependence of glomeruli for filtration pressure but:
• Could try and watch Cr if increases >15-30% stop
- No evidence for stenting
What is essential HTN
Essential (cause unknown) 80-95% of HT
Risk factors • Salt • Obesity • Alcohol • Angiotensin excess • Sympathetic excess • FHx
58-year-old smoker presents with a new diagnosis of HT. His BP has been difficult
to control (190/110) despite amlodipine 10 mg/day and prazosin 5 mg bd.
On examination he has a loud abdominal bruit. His CT scan reveals a 1.5 cm left
adrenal mass. Lab investigations reveal:
Sodium 138 mmol/l [135-145]
Potassium 4.8 mmol/l [3.5 – 5.5]
Bicarb 23 mmol/l [22 – 28]
Creat 105 umol/l [< 120]
The most likely cause of his hypertension is:
A. Conns syndrome
B. phaeochromocytoma
C. essential hypertension
D. renal artery stenosis
E. Cushings syndrome
C. essential hypertension
A 65 y.o. man who weighs 74 kg has a serum creatinine of 125umol/l and the lab
provides an eGFR of 54.7ml/min. What is the most correct interpretation of these
results?
A. the GFR result is an underestimate because he is malnourished
B. the estimated GFR calculations are inaccurate in this range
C. he has significant renal impairment
D. the result should be confirmed with a 24 hour urine collection
E. he should be referred for renal biopsy
C. he has significant renal impairment
Which of the following carries the highest risk for mortality in dialysis patients: A. Serum cholesterol 6.0 mmol/l B. Blood pressure 110/75 C. Serum homocysteine 18 mmol/l (N < 13) D. Body Mass Index (BMI) 36 E. Serum triglyceride 3.0 mmol/l
B. Blood pressure 110/75
A 45 year old man presented with nephrotic syndrome and hypertension. A renal
biopsy revealed focal and segmental glomerulosclerosis, thought to be primary in
origin. His estimated glomerular filtration rate is 40 ml/min/1.73 m2 [normal 90-
150]. He has failed to respond to a prolonged course of prednisolone. Which of
the following approaches to therapy offers the best chance of long-term renal
survival:
A. Fish oil capsules daily for 2 years
B. Cholesterol control with a “statin”.
C. Dietary protein restriction
D. Dietary salt restriction
E. Blood pressure control
E. Blood pressure control
An otherwise stable dialysis patient has the following biochem:
Ca 2.50 mmol/l (N 2.1 – 2.6)
Phos 2.1 mmol/l (N 0.8 – 1.5)
Albumin 44 gm/l (N 35 - 42)
iPTH 35 pmol/l (N < 7)
The patient currently is prescribed CaCO3 600 mg i tds with meals. The most
appropriate next step in management is:
A.Elective parathyroidectomy
B.Increasing CaCO3 to 2 tabs three times a day
C.Adding Al(OH)3 1 tab three times per day
D.Adopting a strict low phosphate diet
E.Adding calcitriol 0.25 ug daily
B.Increasing CaCO3 to 2 tabs three times a day
What is the main factor responsible for systolic hypertension in the elderly? A. Impaired renal perfusion. B. High cardiac output. C. Sympathetic activation. D. Reduced arterial compliance. E. High peripheral resistance.
D. Reduced arterial compliance.
OSA and HTN
- Consider OSA in any patient with HTN and obesity, loud snoring, and/or
daytime sleepiness - OSA is associated with a significant increase in sympathetic activity
during sleep, which in turn causes tachycardia and HTN - OSA and HTN co-exist in patients with resistant HTN in up to 70%
- Diagnosis: sleep studies which consist of attended, in-laboratory polysomnography or unattended, out-of-centre sleep testing
In a 2014 meta-analysis that included 30 randomized trials and over
1900 patients, CPAP therapy was associated with a mean net lowering
in systolic blood pressure of 2.6 mmHg
Conditions other than primary
hyperaldosteronism leading to HTN with
metabolic alkalosis and hypokalaemia
- Conn’s Syndrome (Hyperaldosteronism)
- Cushing Syndrome
- Liddle Syndrome
- Chronic liquorice ingestion
- 11 beta hydroxylase deficiency - 21 hydroxylase deficiency which is the most common of CAH does not cause HTN
- Apparent mineralocorticoid excess (AME)
- Glucocorticoid remediable hypertension
HTN in Liddle syndrome is treated with –
a. Spironolactone
b. Amiloride
c. ACE-I
d. Beta-blocker
e. Thaizide diuretic
b. Amiloride
Most cases of Cushing syndrome is due to:
a. Excess secretion of CRH
b. Excess secretion of ACTH
c. Excess secretion of cortisol
d. Excess secretion of aldosterone
e. Excess secretion of both cortisol and aldosterone
b. Excess secretion of ACTH
- Glucocorticoid remediable hypertension (GRA) is associated with –
a. High PAC and PRA
b. Low PAC and PRA
c. High PAC and low PRA
d. Low PAC and high PRA
e. I am confused………
b. Low PAC and PRA
An obese 29 years old hypertensive patient was evaluated and diagnosed to have Cushing syndrome on the basis of raised urinary cortisol and midnight salivary cortisol. The next step in his evaluation will be –
a. CT scan of the adrenal gland
b. MRI of pituitary
c. ACTH level
d. High dose dexamethasone suppression test
e. PET scan
c. ACTH level
- An adrenal incidentaloma is most likely to
a. Cause Cushing syndrome
b. Be a primary malignancy
c. Be a benign non-secretory tumour
d. Cause hyperaldosteronism
e. Be a Pheochromocytom
c. Be a benign non-secretory tumour
- A 49-year-old woman with no previous medical history presents with BP of 180/100 mm Hg and hypokalemia with alkalosis. Which of the following is unlikely to have led to this condition?
a. Gitelman syndrome
b. Renovascular hypertension
c. Primary aldosteronism
d. Unilateral renal artery stenosis
a. Gitelman syndrome
What antihypertensives can be used in pregnancy?
methyldopa, labetalol, hydralazine, nifedipine
Moms Love Healthy Newborns
Calcium channel blockers
MOA
SE
Indications
Verapamil mainly acts on Ventricles
Amlodipine mainly acts on Arteries
Dihydropyridines (eg: amlodipine, nifedipine)
MOA: potent vasodilator via relaxation of vascular smooth muscle, minimal myocardial depressant activity
SE: headache, peripheral oedema, flushing, reflex tachycardia, gingival hyperplasia
Indications:
Arterial HTN
Angina
Raynaud
Non-dihydropyridines (eg: verapamil, diltiazem)
MOA: moderate vasodilator, potent myocardial depressant especially verapamil
SE: decrease contractility, bradycardia, AV block, gingival hyperplasa
Verapamil - constipation, hyperprolactinaemia
Indication: atrial hyperventilation, SVT, angina, HOCM, verapamil can also be used for migraines
What should non dihydropyridines (eg: verapamil, diltiazem) not be combined with?
Should not be combined with BB as can enhance the negative inotropic, chronotropic and dromotropic effects of beta blockers
What is inotropy, chronotropy, dromotropy, lusitropy
Stimulation of the Beta1-adrenergic receptors in the heart results in positive inotropic (increases contractility), chronotropic (increases heart rate), dromotropic (increases rate of conduction through AV node) and lusitropic (increases relaxation of myocardium during diastole) effects.
What is verapamil contraindicated in?
Contraindicated in heart failure due to their negative effect on mycardial contractility
What are contraindications of all calcium channel blockers and then specifically dihydropyridines/non dihydropyridines?
All CCB
- Symptomatic hypotension
- ACS
Dihydropyridines
- HOCM
- Severe stenotic heart valve defects
Non dihydropyridines Pre-existing cardiac conduction disorders - WPW - Sick sinus - Systolic dysfunction in CCF - Bradycardia
Side effects of ACE inhibitors, ARBs
Dry cough
Angioedema
First dose hypotension
Hyperkalaemia
SE of thiazide diuretics
Reduce potassium and sodium
Increase glucose, cholesterol
Increase reabsorption of Ca (so high serum Ca, low Ca in urine) in DCT and PCT (independent of Na effects) - useful in treatment of recurrent kidney stones in hypercalciuria
Prazosin
Indication
MOA
SE
Indication: HTN for pheochromocytoma, adjunct to patients with BPH
MOA: alpha 1 blocker
SE: headache, postural hypotension
Clonidine
Rarely used
Alpha 2 agonist
SE: CNS depression, bradycardia, rebound hypertension
Hydralazine
MOA
SE
MOA: Direct arteriolar vasodilator
SE: reflex tachycardia, sodium + water retention
