Hypertension Flashcards
(17 cards)
Monogenic causes lead to what proportion of hypertensive cases? And example of such
Monogenic disease causes <1% of hypertension
Liddle’s syndrome
Mutation in amiloride-sensitive tubular epithelial Na channel
Apparent mineralocorticoid excess
Mutation in 11b-hydroxysteroid dehydrogenase
Polygenic causes of hypertension
Complex polygenic causes
Multiple genes with small effects (positive and negative)
Interactions with sex, other genes, environment
Dietary salt intake is one of the main factors in increase of bp with age
Isolated systolic hypertension
Systolic pressure greater than 140 and diastolic pressure is less than 90
Found in people older than 60
Due to the stiffening of the middle/large arteries which means that the pulse wave is reflected and is greater by the time it reaches the brachial artery
Does not mean that TPR rises
Causes of primary hypertension.
Kidney
Increased sympathetic activity
Endocrine and paracrine factors
Explain how the role of the kidney leads to hypertension
Most common secondary cause
Major influence of booking due to regulation of salt and water regulation
damage caused by high blood pressure
increased risk of
- coronary heart disease
- stroke
- peripheral vascular disease
- heart failure
- atrial fibrillation
- dementia
- retinopathy
what does hypertension do to the heart?
associated with an increase in left ventricular wall mass (LVMI) and changes in chamber size
hypertension and large arteries
may cause arterial rupture or dilations (aneurysms). This can lead to thrombosis or haemorrhage
Hypertension and the eye
the retina illustrates microvascular damage in hypertension. This is thickening of the wall of small arteries, arteriolar narrowing, vasospasm, impaired perfusion and increased leakage into the surrounding tissue
hypertension and the microcirculation
the retina illustrates microvascular damage in hypertension. There is thickening of the wall of small arteries, arteriolar narrowing vasospasm, impaired perfusion and increased leakage into the surrounding tissue.
Hypertension is associated with: reduction in capillary density, elevated capillary pressure and damage ad=nd leakage.
what changes can be seen in the kidney due to hypertension
granular capsular surface
cortical thinning, renal atrophy
subcapsular haemorrhages
blood pressure and microalbuminuria
hypertension causes increased albumin loss in the urine
hypertension causes reduced glomerular filtration rate
GFR declines with age even without high BP, which speeds up deterioration
treatments for hypertension
ACE inhibitors and angiotensin receptor blockers
Diuretics
Beta blockers
Calcium channel blocker
How do ACE inhibitors and angiotensin receptor blockers work?
reduces the production of angiotensin II
increases
- arteriolar vasoconstriction
- sympathoexcitation
- both lead to increased vascular resistance
decreases:
- ADH secretion
- aldosterone secretion
- tubular sodium reabsorption
* increased water retention
How do diuretics work?
Loop diuretics: used in a crisis to block water reabsorption
thiazide diuretics: thiazides and thiazide-like diuretics do not work through diuresis but because they slowly reduce PVR, mechanisms still uncertain
How do beta blockers work?
- blockage of B1 receptors in heart
- reduced rate and force of contraction
- reduced cardiac output
- blockage of B1 receptors in kidney
- reduced secretion of renin
- reduced activity of RAAS (renin–angiotensin–aldosterone system)
How do calcium channel blockers work?
In vascular smooth muscle
- reducing Ca2+ influx reduces actin myosin cross bridge cycling
In the heart
- inhibition of Ca2+ influx reduces contractility (neg inotrophy) and rate of conduction (neg dromotrophy)
