hypertension Flashcards
how to calculate BP
cardiac output X total peripheral resistance
causes of hypertension
primary hypertension - naturally (idiopathic)
secondary hypertension - underlying condition eg endocrine, renal, drugs, pregnancy
malignant hypertension - severe inc, emergency
examples of secondary causes.
renal:
ckd
renal scarring
fluid overload
endocrine:
primary aldosteronism
cushings
hyperthyroidism
thyroid disease
acromegaly
CVD:
renovascular disease
co-arctation of aorta
define resistant hypertension
Definition: uncontrolled BP on 3 - 4 agents including a diuretic
most common cause of secondary hypertension, tests and treatment
primary aldosteronism
- adrenal adenoma
- hyperplasia
Screening test is aldosterone:renin ratio (likely if ratio is high)
Confirmatory tests: saline infusion test, adrenal vein sampling for lateralization study
surgery
Spironolactone
Management of resistant hypertension
Check modifiable lifestyle changes (salt and alcohol intake, BMI)
Check compliance – history, repeat prescription, adherence test
Simplify meds - once daily dose, combination tablet, Nomad
Additional agents – balance risk v benefit, law of diminishing returns
Refer to hypertension specialist – evaluation of secondary causes
difference between ABPM HBPM.
ABMP - 24hr ambulatory BP monitoring
- used more for diagnostic and specialised
HBMP - home blood pressure monitoring
- 2X readings
- twice daily
- for 7 days
- used more for assessment and lifestyle changes
hypertension epidemiology
- Affects >1 billion adults worldwide
- Could reach 1.5 billion in 2025
- 45% of adult population
- 60% of population age >60
Assessments for hypertension severity? (4)
Assess end organ damage (more damage = worse prognosis) :
- Fundoscopy: assess for hypertensive retinopathy
- 12- lead ECG: assess for LVH
- Urinalysis and ACR: assess for renal dysfunction + diabetes risk
- Bloods: HbA1c, U&Es, total cholesterol, HDL cholesterol
Complications for hypertension? (6)
Heart failure
Increased IHD risk
CKD/Renal failure
PVD
Dementia
Increased risk of cerebrovascular incident
How many drugs are generally needed to control blood pressure?
Mostly one or two
Signs of malignant hypertension (4)
Hypertensive retinopathy
Visual disturbances
Cardiac symptoms eg chest pain
Oliguira or polyuria
Overall rare but scary and unrelated to cancer just very severe symptoms
Define the limits for stages of hypertension (3)
stage 1 (mild) - H - 140/90 A - 135/85
stage 2 (moderate) H - 160/100 A - 150/95
stage 3 (severe) - 180 and or </= 110
How to diagnose hypertension (3)
If bp reading in hospital is between 140/90 and 180/120 mmHg then offer ABPM to confirm diagnosis
-bp is measured for 24h with at least 2 measurements per hour during waking hours
-overall at least 14 measurements are required
if >/= 135/85 - stage 1
treat if:
- <80yrs
- diabetic
- CVD
- renal disease
Qrisk over 10%
if >/= 150/95 - stage 2
- treat all patients regardless of age
If a patient has T2DM and is black or 55+, would they take CCB or ACEi?
T2DM takes precedence and they should take ACEi
BUT ARBs are preferred for black patients so that might be preferable
Limits for diagnosing hypertension (2)
> = 140/90 mmHg in clinic
> = 135/85 mmHg at home (ambulatory blood pressure monitoring)
Pathophysiology of hypertension (2)
Ultimately all mechanisms will increase RAAS and SNS activity (CO) and TPR
=> increase in BP as BP=COxTPR
Symptoms of hypertension (2)
Mostly asymptomatic and found in screening
May have pulsatile headache, classically occipital and worse in the morning
Targets for blood pressure after treatment? (5)
- Routine <140/90 mmHg
- Previous stroke < 130/80mmHg
- Heavy proteinuria <130/80mmHg
- CKD and Diabetes <130/80mmHg
- older patients <150/90mmHg
Thresholds for treatment for hypertension? (2)
Low CVD risk 160/100mmHg
High CVD risk 140/90mmHg
(Clinic thresholds)
What reduction do you expect with a full dose of any single drug? (2)
Systolic: 8-10mmHg
Diastolic: 4-6mmHg
common drugs used to treat hypertension
ACE inhibitors - vasodilation - first line in <55yrs
calcium channel blockers - relax cardiac muscle - first line treatment in >55yrs
thiazide type diuretics - inhibit Na absorption in kidney
A2RB - used when patient cant handle ACE inhib
when is first line drug ACE and when is it CCB?
ACE - <55 / T2DM
CCB - >55yrs or black / no T2DM
if first line drig is ineffective what other combos of drug is administered?
ACE + CCB OR ACE + DIURECTIC
CCB + DIURETIC or ACE
if still ineffective - ACE + CCB + diuretic
IF K<4.5 - LOWDOSE SPIRONOLACTONE
IF K >4.5 ADD ALPHA OR BETA BLOCKER
can atherosclerosis develop in capillaries?
no they’re too small
