Case 8 - Hypertension Flashcards
What is classified as hypertension?
Blood pressure >140/90 mmHg
What are the different types of hypertension?
- Primary (essential): no detectable cause
- Secondary: due to underlying disease
What are the causes of primary hypertension?
- Non modifiable risk factors: positive family history, ethnicity, older age
- Modifiable risk factors: obesity, diabetes, smoking, high salt diet, low potassium diet, inactivity, stress, excess alcohol and caffeine
What are the causes of secondary hypertension?
- Primary aldosteronism (most common)
- Renovascular disease (fibromuscular dysplasia)
- Oral contraceptive
- NSAIDs
- Stimulants (cocaine)
- Antidepressants
- Pheochromocytoma
- Cushing’s syndrome
- Coarctation of the aorta
- Hyper/hypothyroidism
- Primary hyperparathyroidism
- Brain tumours
- Encephalitis
- Pregnancy
- Methamphetamines
How can brain tumours and encephalitis lead to hypertension?
Decreased blood flow to brain ->
CNS vasopressor response
How can obesity lead to hypertension?
Increased body weight -> Increased plasma volume -> Increased cardiac output
How does medial fibromuscular dysplasia cause hypertension?
- This causes abnormal growth within the renal artery leading to renal artery stenosis.
- It has a string ob beads appearance due to the alternating aneurysms that cause the stenosis.
What are the symptoms of hypertension?
- Often asymptomatic
- Headaches (waking headaches)
- Epistaxis
- Fatigue, sleep disturbance due to nocturnal hypertension
- Chest discomfort, palpitations
- End organ damage symptoms
What are the different ways to diagnose hypertension?
- Measure in the clinic
- Ambulatory home blood pressure
- Home blood pressure monitoring
How is hypertension in the clinic diagnosed?
- Measure in both arms
- Should be 140/90 mmHg or higher
- Take 2 readings
- Record lower of the 2 measurements.
How is ambulatory hypertension interpreted?
- Used to confirm hypertension
- 2 measurements taken every hour during waking hours
- Average of last 14 results
- Requires an average of >135/85 mmHg
Why and how is home blood pressure monitoring used?
- Used if can’t tolerate ABPM
- Seated with 2 consecutive readings taken with at least 1 min apart.
- Recorded 2x daily
- At least 4 days, ideally 7 days
- Requires an average of >135/85 mmHg
How is postural hypotension measured?
1) Measure when supine
2) Measure when standing for at least 1 min prior measurement
What is stage 1 hypertension?
Systolic: 140-159
Diastolic: 90-99
What is stage 2 hypertension?
Systolic: 160-179
Diastolic: 100-109
What is stage 3 hypertension?
Systolic: ≥180
Diastolic: ≥110
What is isolated systolic hypertension?
Systolic: ≥140
Diastolic: ≤90
How to treat isolated systolic hypertension?
- Thiazide diuretic or
- Dihydropyridine calcium antagonists
What investigations are done for hypertension?
- ECG - left ventricular hypertrophy or concomitant heart disease (e.g., coronary artery disease, arrhythmias)
- FBC count
- Renal function – urea, creatinine and eGFR
- Random blood sugar
- Total cholesterol and HDL cholesterol
- Urine – To detect microalbuminuria and/or haematuria, estimation of albumin: creatinine ratio, hypokalaemia
- TSH – high or low if thyroid dysfunction
- CXR - may show LVH
What is the QRISK2 score?
Calculates % risk of having heart attack or stroke in next 10 years.
When is QRISK2 score valid?
If patient does NOT have a diagnosis of previous coronary heart disease/stroke/TIA
How to conservatively treat hypertension?
- Healthy diet
- Reducing sodium, caffeine
- Increasing potassium intake
- Weight loss
- Regular exercise
What is the step 1 drug treatment for hypertension?
If <55y - ACEi OR ARB
If >55y/Asian/Afro-Caribbean - CCB. (thiazide if not CCB)
What is the step 2 drug treatment for hypertension?
ACEi/ARB + CCB (thiazide if not CCB)
