Hypertension pathophysiology, presentation and investigation Flashcards
Small rise in blood pressure can cause what
big change to outcomes
blood pressure is the world’s…
number 1 cause of preventable morbidity and mortality
end-organ damage examples in hypertension
Brain - haemorrhage, stroke, cognitive decline
Heart - LVH, CHD, CHF - congestive heart failure, MI
Eyes - retinopathy
Kidney - renal failure, dialysis, transplantation, proteinuria
definition of hypertension
That blood pressure above which the benefits of treatment outweigh the risks in term of morbidity and mortality
At what blood pressure is a patient hypertensive
140/90
what issues are there with blood pressure readings
they’re not very accurate - would need to do 30 readings to get within 10% of actual blood pressure
ABPM benefits over clinic
some patients’ blood pressure increases a lot in clinic due to related stress or angst so monitoring it at home is more accurate
primary/essential hypertension
90% of cases no cause can be found
secondary hypertension
5-10% a cause can be found
chronic renal disease Renal artery stenosis
Endocrine disease, Cushings, Conn’s Syndrome, Phaeochromocytoma, GRA
Renin-Angiotensin-Aldosterone System
responsible for maintenance of sodium balance, control of blood volume, control of blood pressure
what is RAAS stimulated by
fall in BP
fall in circulating volume
sodium depletion
renin is released from the juxtaglomerular apparatus
polygenic causes of hypertension
major genes
polygenes - polygenic multifactorial disorder involving the interaction of several genes with environmental factors
polyfactorial causes of hypertension
environment
individual and shared
general factors that cause hypertension
Age Genetics and family history Environment Weight Alcohol intake Race/ethnicity
Age and hypertension
BP increases with age
Genetics and hypertension
tends to run in family
closest correlation - runs with siblings
siblings have shared parents and environment
Environment and hypertension
Mental and physical stress both increase blood pressure
sodium intake link to blood pressure
lower salt intake - lower blood pressure and vice versa
medication is far more effective when salt intake is lowered
what is an under recognised cause of severe hypertension
sleep apnoea
Race and hypertension
Caucasians have a lower BP than black
Stroke Is more common in people who moved to UK from populations that aren’t used to high salt environment – genetics
which is the most fatal risk factor?
low fitness
prime contributors to blood pressure
cardiac output - stroke volume and heart rate
peripheral vascular resistance
sympathetic nervous system and blood pressure
Sympathetic system activation produces
vasoconstriction,
reflex tachycardia and increased cardiac output
In this way blood pressure is increased
The actions of the sympathetic system are rapid and account for second to second blood pressure control
sodium’s effect on blood pressure: primary hypertension
the kidneys are unable to excrete appropriate amounts of sodium for any given BP. As a result sodium and fluid are retained and the BP increases
alcohol link to blood pressure
One of the most common causes of hypertension in the young Scot
Affects 1% of the population
Small amounts of alcohol tend to decrease BP
Large amounts of alcohol tend to increase BP
If alcohol consumption is reduced BP will fall over several days to weeks.
How does weight affect blood pressure
Obese patients have a higher BP
Up to 30% of hypertension is attributable in part or wholly to obesity
If a patient loses weight BP will fall
Weight reduction is the most important non-pharmacological measure available
How does your birth weight affect blood pressure
Birth weight is also associated with the development of hypertension in later life.
The lower the birth weight the higher the likelihood of developing hypertension and heart disease
EWPHE study (European Working Party on High Blood Pressure in the Elderly )
study that has proven that treating both diastolic and systolic hypertension in the elderly significantly reduces stroke and MI
MRC studies
medical research council
SHEP studies
Systolic Hypertension in the Elderly Program
systolic hypertension
defined as an elevated systolic blood pressure
Understanding a blood pressure value ie(<120/80)
Your systolic blood pressure is the top number on your reading. It measures the force of blood against your artery walls while your ventricles contract, pushing blood out to the rest of your body
Your diastolic blood pressure is the bottom number. It measures the force of blood against your artery walls as your heart relaxes and the ventricles are allowed to refill with blood.
