Essential or secondary hypertension Flashcards
Define hypertension
Defined as a blood pressure persistently (on 3 separate occasions) ≥140/90 mmHg + 24 hour blood pressure average reading (ABPM/HBPM) ≥135/85 mmHg
Summarise the epidemiology of hypertension
● VERY COMMON
● 10-20% of adults in the Western world
Explain the aetiology/cause of hypertension
- Primary (Essential) Hypertension (90%) → hypertension with no identifiable cause
- Secondary Hypertension (10%) → hypertension caused by an identifiable underlying condition (eg. renal artery stenosis, primary hyperaldosteronism - conn syndrome, cushing syndrome, phaeochromacytoma, acromegaly):
-Primary Hyperaldosteronism is most common cause of secondary hypertension
What are different secondary causes of hypertension?
- Renal
● Renal artery stenosis
● Chronic glomerulonephritis
● Chronic pyelonephritis
● Polycystic kidney disease
● Chronic renal failure
● Renovascular disease - Endocrine
● Diabetes mellitus
● Hyperthyroidism
● Cushing’s syndrome
● Conn’s syndrome
● Hyperparathyroidism
● Phaeochromocytoma
● Congenital adrenal hyperplasia
● Acromegaly - Cardiovascular
● Coarctation of the aorta
● Increased intravascular volume - Drugs
● Sympathomimetics
● Corticosteroids
● COCP - Pregnancy
● Pre-eclampsia
Recognise the presenting symptoms of hypertension
● Often ASYMPTOMATIC
● Symptoms of complications
● Symptoms of the cause
● Accelerated or Malignant Hypertension:
-Scotomas (visual field loss)
-Blurred vision
-Headache
-Seizures
-Nausea and vomiting
-Acute heart failure
Recognise the signs of hypertension on physical examination
- Blood pressure should be measured on 2-3 different occasions before diagnosing hypertension
- The lowest reading should be recorded.
- Radiofemoral delay = coarctation of the aorta distal to the left subclavian artery
- Renal artery bruit = renal artery stenosis
- Fundoscopy to detect hypertensive retinopathy
Identify appropriate investigations for hypertension
- Clinic BP(3 readings 5 minutes apart)
- Ambulatory blood pressure monitoring or Home blood pressure monitoring (if ABPM not tolerated)
- Excludes white coat hypertension (discrepancy >20/10mmHg between clinic and ABPM/HBPM reading)
- Other investigations may be performed if a secondary cause of the hypertension is suspected (e.g. renal angiogram, plasma renin & aldosterone if conn’s suspected) - Bloods:
- U&Es
- HbA1c
- Lipid profile (total cholesterol & non-HDL cholesterol) - Urine Dipstick
- Blood and protein (e.g. if glomerulonephritis)
- Albumin: creatinine ratio (ACR) - ECG
- May show signs of left ventricular hypertrophy or ischaemia
- Consider seeking specialist evaluation of secondary HTN causes for anybody under 40with HTN
Generate a management plan for hypertension
- Lifestyle Advice → weight loss, decrease dietary sodium, decrease alcohol intake, exercise, smoking cessation
- Investigate for secondary causes(mainly in young patients <40)
- DRUGS:
a. step 1:
- < 55y/o or T2DM: ACEi or ARB (ARB should be used where ACEi’s are not tolerated (e.g. due to a cough))
- > 55y/o or black African or African–Caribbean origin= CCB
b. step 2:
- if already taking an ACE-i or ARB add a CCB or a thiazide-like Diuretic
- if already taking a CCB add an ACEi or ARB or a thiazide-like Diuretic (indapamide- less side effects than a real thiazide)
c. step 3:
- add a third drug (thiazide dieuretic or CCB- whichever they weren’t taking before)
d. step 4:
- first, confirm for:
*confirm elevated clinic BP with ABPM or HBPM
*assess for postural hypotension.
*discuss adherence
- add a 4th drug (as below) or seeking specialist advice:
*if potassium < 4.5 mmol/l add low-dose spironolactone
*if potassium > 4.5 mmol/l add an alpha- or beta-blocker (contraindicated if asthmatic) - HTN annual review:
- Check BP
- Check renal function: bloods: U&Es, Cr, eGFR, urine dipstick for protein
- HbA1c
- Assess QRISK (consider statin if >10%)
What are the different bp targets of different ages?
<80:
- Clinic bp: 140/90
- ABPM/HBPM: 135/85
>80:
- Clinic bp: 150/90
- ABPM/ HBPM: 145/85
How is Accelerated/Malignant Hypertension Managed?
- Emergency same day referral (if in primary care) for specialist review & treatment
- IV beta-blocker (e.g. labetolol) or nifedipine
CAUTION: avoid rapid lowering of blood pressure because it can cause cerebral infarction - This is because the autoregulatory mechanisms within the brain for regulating blood flow will cause vasoconstriction of the vessels in the brain when blood pressure is very high
- Lowering the blood pressure too rapidly would mean that the autoregulatory mechanisms do not adapt to the drop in blood pressure and so the vessels remain constricted
- If BP < 140mm/Hg, check BP at least every 5 years
Identify the possible complications of hypertension
● Heart failure
● Coronary artery disease
● Cerebrovascular accidents
● Peripheral vascular disease
● Emboli
● Hypertensive retinopathy
● Renal failure
● Hypertensive encephalopathy
● Posterior reversible encephalopathy syndrome (PRES)
● Malignant hypertension
Summarise the prognosis for patients with hypertension
● Good prognosis if well controlled
● Uncontrolled hypertension is associated with increased mortality
● Treatment reduces incidence of renal damage, stroke and heart failure
● Causes 50% of all vascular deaths
What are the risk factors for hypertension?
- age >65 yrs
- alcohol intake
- lack of exercise
- any FH of hypertension
- obesity
- DM
- black ancestry
- diet high in sodium
What are the different stages of hypertension?
- Stage 1 → clinical BP ≥140/90mmHg and ABPM/HBPM ≥135/85mmHg
- In those >80 years old, don’t treat stage 1 hypertension (only stage 2) - Stage 2 → clinical BP ≥160/100mmHg and ABPM/HBPM ≥150/95mmHg
- Stage 3 (Severe) → clinical systolic ≥180mmHg or diastolic ≥120mmHg
What system is used to classify hypertensive retinopathy?
SAFP:
Silver wiring
+ arteriovenous nipping
+ flame haemorrhages + cotton wood exudates
+ papilloedema
