Hypertension Flashcards
(21 cards)
How many people does hypertension affect
2 billion
What is the target systolic BP
120
Give some identifiable causes of hypertension
Renal disease, including renal artery stenosis
Tumours secreting aldosterone (Conn’s)
Tumours secreting catecholamines (pheochromocytoma)
Oral contraceptive pill
Pre-eclampsia / pregnancy associated hypertension
Rare genetic cause e.g. Liddle’s syndrome
What causes of hypertension are primary or essential
unidentifiable
genetic or environmental
Give examples of unidentifiable causes
Liddle’s syndrome
Complex polygenic
Dietary salt (sodium) Obesity / overweight, lack of exercise Alcohol Pre-natal environment (~birthweight) Pregnancy (pre-eclampsia)
How does age affect blood pressure
mean BP and pulse pressure increases
Diastolic BP does not
those >60 would be expected to be hypertensive
What is hypertension associated with haemodynamically
Increased total peripheral resistance Decreased arterial compliance Normal cardiac output Normal blood volume / ECV Central volume shift
What can increased TPR be caused by
Vasoconstriction
Growth and remodelling (structural narrowing)
Capillary loss through rarefaction
Define isolated systolic hypertension
systolic blood pressure ?140
diastolic <90
Increased stiffness of medium/large arteries e.g. brachial, femoral
Pulse wave is reflected and much greater
How is the kidney involved in hypertension
Key role in BP regulation
Regulation of sodium, water and extracellular fluid
What factors have been associated with hypertension
Endocrine and paracrine factors
SNS
How does hypertension affect the large arteries
May cause arterial rupture or dilations (aneurysms)
Leads to thrombosis or haemorrhage (i.e. strokes)
How does hypertension affect the eye and microcirculation
The retina illustrates microvascular damage
Thickening of the wall of small arteries, arteriolar narrowing, vasospasm, impaired perfusion and increased leakage into the surrounding tissue
How does hypertension affect the kidney
Renal dysfunction e.g increased albumin excretion in the urine
Extreme is rare but leads to rapidly progressive renal failure
What lifestyle modifications can be made for hypertension
Weight loss
Exercise
Eat healthy
Less alcohol
What treatments are available for hypertension
ACE inhibitors Angiotensin receptor blockers Diuretics Beta blockers Calcium channel blockers
What are ACE inhibitors
Inhibit ACE so that less angiotensin I is converted to angiotensin II
Effects include
Reduced aldosterone release, ADH secretion, sodium reabsorption, sympathoexcitation, arterial vasoconstriction
What are diuretics
Used in patients experiencing a hypertensive crisis (large fluid overload)
Thiazides and thiazide-like product reduce PVR
What are beta blockers
blockage of the beta1 receptors in the heart or kidney
Reduces rate and force of contraction, cardiac output, renin secretion, activity of RAAS
What are calcium channel blockers
Reduces calcium influx and actin myosin cross bridge cycling
Inhibits calcium influx that reduced contractility (negative inotropy) and rate of conduction (negative dromotropy)
Define hypertension
The level of blood pressure above which investigation and treatment do more good than harm
