Hypertension Flashcards
How many people die in a year from hypertension in the US
What should your mean bp be
What does testosterone do
How does age affect bp
One million
90mmHg
Increases bp
Increases it
What is a normal diastolic bp
What is a normal systolic bp
Less than 85
Less than 140
Figures for mild hypertension d
Moderate d
Severe d
Borderline systolic hypertension
Isolated systolic hypertension
90-104
105-114
114+
140-159
160+
Two types of hypertension
Essential -
No clear cause it just develops and there are risk factors that may have increased the chances.
Secondary-
Happens as a consequence of another clinical condition usually renal.
Potential causes of essential hypertension 6
Cardiac output tends to decrease with age because the heart muscle wares out.
Total peripheral resistance increases with age due to arteriosclerosis (hardening of arteries) causing increased resistance.
So age may be a cause.
Cardiac dysfunction- someone’s with EH will have an increased response to stress and catecholamines.
Vessel abnormalities- too many chemicals released which cause vasoconstriction.
Produce low amounts of NO and EDRF so they have abnormally functioning endothelial cells in the vessels.
Smooth muscle ion channel deficits which don’t respond correctly to catecholamines.
Muscle hypertrophy due to the increase pressure which makes it grow to cope.
Kidney dysfunction as they can’t maintain the correct blood volume and this will cause hypertension.
How do you calculate the mean arterial bp
Cardiac output times total peripheral resistance
Genes and the environment affecting essential hypertension
What about polymorphism
EH correlated with relatedness which is proven by twin studies.
30-50% genetic predisposition
5+ unproven genes that are maybe.
Polymorphism in genes for angiotensinogen and ENAC increase the risk.
Varies with race. Higher prevalence in African carribean.
Diet and obesity increases risk.
Salt intake
Vitamin D deficiency
Salt affecting bp
There is a single known mutation in various receptors that will change the uptake of Na and Cl causing increased retention.
Blood pressure increases as salt intake increases. Animal studies.
What can cause secondary hypertension
Renal artey stenosis
Pheochromocytomas
Hormones
Mostly comes with renal diseases as the nephron function is impaired.
Blood volume will increase as the kidneys can’t regulate it. And this will damage the kidneys even more.
Renal artery stenosis- narrowing of arteries into the glomerulus so less blood is being filtered and less salt is removed causing a high bp.
Pheochromocytomas- tumour of medulla and renal gland.
Hormone imbalance- aldosterone increases Na and bp. Adrenal rumours can alter the amount of aldosterone produced.
Consequences of hypertension
The three As
Heart affects
Retina
There are thought to be no symptoms it’s a silent killer.
But some could be flushing, sweating, blurred vision, headaches.
Arteriosclerosis- hardening of arteries and increased resistance.
Atherosclerosis- fatty plaques narrowing arteries made worse by hypertension
Aneurysm- aortic diameter can increase from 2.5-8cm by ballooning. They can burst or have a slow leak. A graft can be put in. Causes back pain.
Stroke- the increased pressure can cause a brain aneurysm leading to a stroke.
Myocardial infarction- coronary arteries athero or arteriosclerose causing heart attack.
Retinal damage- the first place hypertension can be found. You can see exudates which is fluid leaking from arteries which can be seen as dark spots on the retina exam. Hard exudates have been calcifies and are white.
Non drug treatment
Weight loss
Exercise
Diet
Reduce salt and alcohol and caffeine
Stop smoking
Relaxation
Drug treatment 5
Diuretics- thiazides increase urine production to lose fluid and excrete more salt.
Sympatholytics- agonist of alpha adrenoreceptor blockers to reduce vascular tone by reducing sympathetic output.
Clonidine- decreases CNS output to relax smooth muscle.
Beta blockers reduce contractility of the heart and heart rate. Propanolol.
Ca channel blockers stop smooth muscle contraction in vessels.
ACE inhibitors
What is wrong with them and what’s an alternative
Inhibit vascular remodelling and proliferation of muscle cells. To stop muscles being able to contract harder in the heart and causing bp increase.
They also stop the renin angiotensin system from increasing bp. Moexpril
They can cause a cough due to the bradykinins.
Instead you can use angiotensin 2 receptor blockers that stop the renoangiotensin system for example the sartan family.
Dual approach for treatment
They usually give a diuretic and something else.
Although diuretics have been found to be ineffective.
So two others will be used together.
