Essential or secondary hypertension (CV) Flashcards
What is hypertension?
- blood pressure that is persistently >/=140/90 mmHg
- AND
- 24 hour blood pressure average reading (ABPM/HBPM) >/=135/85 mmHg
What is essential/primary hypertension?
Persistently raised BP with no identifiable/secondary cause identified
What is secondary hypertension?
Hypertension caused by an identifiable underlying cause
What is the most common cause of secondary hypertension?
Conn’s syndrome - primary hyperaldosteronism
What are some other causes causes of secondary hypertension? (9)
- (Conn’s syndrome = most common)
- renal stenosis
- chronic renal failure
- Cushing’s syndrome
- phaeochromocytoma
- acromegaly
- hyperthyroidism
- coarctation of the aorta
- combined OCP
- pre-eclampsia
What are some causes of essential hypertension?
- disturbance of auto-regulation (reflex and persistently increasing vascular resistance to match an increased cardiac output)
- excess sodium intake
- renal sodium retention
- RAAS dysregulation (increased plasma renin –> increased angiotensinogen, AT1, AT2 –> vasoconstriction)
- increased sympathetic drive
- increased peripheral resistance
- endothelial dysfunction
- cell membrane transporter perturbations
- insulin resistance/hyperinsulinaemia
How does hypertension usually present?
Often asymptomatic (incidental finding) - unless BP is very high
What are some non-specific symptoms of hypertension? (6)
- headache
- visual changes (blurred vision)
- dyspnoea
- chest pain
- motor/sensory deficit
- dizziness
What might you see on examination of hypertension?
- systolic BP>140 mmHg and/or diastolic BP>90 mmHg measured on three separate occasions
- hypertensive retinopathy
- radiofemoral delay = coarctation of the aorta distal to the left subclavian artery
- renal artery bruit = renal artery stenosis
- palpable kidneys
- signs of phaeochromocytoma or Cushing’s
How is hypertensive retinopathy classified?
Keith-Wagner Classification:
- grade I: silver wiring (line down middle of arterioles)
- grade II: silver wiring + AV nipping (artery crosses vein and nips it, causing vein to narrow)
- grade III: flame haemorrhage, sometimes cotton wool spots too
- grade IV: papilloedema (cannot see optic disc) - either due to chronic hypertension or intracranial hypertension (from brain tumour), needs admission
When can orthostatic hypertension be diagnosed?
When there is a drop in SBP >/=20 mmHg and/or a drop in DBP >/=10 mmHg after 3 minutes of standing
What are some risk factors for hypertension? (9)
- obesity
- aerobic exercise <3 times/week
- alcohol intake
- metabolic syndrome
- diabetes mellitus
- black ancestry
- age >60 years
- Fx of hypertension or chronic coronary disease
- sleep apnoea
What is the 1st line investigation for hypertension?
Ambulatory blood pressure monitoring (ABPM) - measures BP at fixed intervals over 12-24 hours allowing average to be taken
If ABPM is declined for hypertension, what is the next step?
Home BP monitoring, measured by individual at periodic intervals
What other investigations can be done alongside ABPM to investigate hypertension? (6)
- ECG - check for left ventricular hypertrophy or old infarction
- fasting metabolic panel with eGFR - renal insufficiency, hyperglycaemia, hypokalaemia, hyperuricaemia, hypercalcaemia
- lipid panel
- urinalysis - may show proteinuria/haematuria
- Hb - anaemia/polycythaemia suggest secondary cause or complication
- TSH - high or low if thyroid dysfunction
If new BP is >180/120 mmHg, what is this indicative of and what investigations can we do to assess this?
End organ damage
- fundoscopy - retinopathy
- urine dipstick - renal disease
- ECG - LVH
What are some differential diagnoses for hypertension?
- drug-induced
- CKD
- renal artery stenosis (renal duplex US/magnetic resonance angiogram, treated with renal balloon)
- aortic coarctation
- OSA
- hyperaldosteronism
- hypo/hyperthyroidism
- hyperparathyroidism
- Cushing’s syndrome
- phaeochromocytoma
- acromegaly
- collagen vascular disease
- gestational hypertension
What do we offer to patients with BP between 140/90 and 180/120?
- offer ABPM
- offer to test urine ACR, haematuria, HbA1c, electrolytes, creatinine, eGFR, cholesterol, fundoscopy, ECG
- estimate Q-risk
What do we do if a patient presents with BP>180/120?
- same day referral if retinopathy, confusion, chest pain, heart failure, AKI
- start antihypertensive drug
- if no target organ damage: repeat reading in 7 days
What are the stages of hypertension?
- stage 1 HTN: clinic >140/90, ABPM >135/85
- stage 2 HTN: clinic >160/100, ABPM >150/95
- stage 3 HTN: clinic >180/120
What do you do if a patient under 40 presents with hypertension?
Seek specialist evaluation for secondary causes
How do you treat secondary hypertension?
Treat underlying cause FIRST
What lifestyle modification advice can you give to patients with hypertension? (5)
- smoking cessation
- weight loss
- exercise
- reduce alcohol intake
- reduce dietary sodium
What are some examples of ACE inhibitors?
Ramipril, lisinopril
