Hypertension Pathophysiology, Presentation and Investigation Flashcards
What is hypertension?
The blood pressure above which the benefits of treatment outweigh the risks in terms of morbidity and mortality
According to NICE 2011 definitions, what is stage 1 hypertension?
Clinical BP of 140/90mmHg or higher
ABPM daytime average of 135/85mmHg or higher
According to NICE 2011 definitions, what is stage 2 hypertension?
Clinical BP of 160/100mmHg or higher
ABPM daytime average 150/95mmHg or higher
According to NICE 2011 definitions, what is severe hypertension?
Clinical systolic BP of 180mmHg or higher, or diastolic BP of 110mmHg or higher
In 95% of cases of hypertension, no cause can be found, what are these cases known as?
Primary hypertension
The 5-10% of cases of hypertension for which a cause can be found are known as what?
Secondary hypertension
What percentage of cases of hypertension are primary and what percentage are secondary?
95% primary
5-10% secondary
Does removal of the cause of secondary hypertension cure the hypertension?
No - removal of cause does not guarantee that the hypertension or associated risk will return to normal
What percentage of resistant hypertension is renal disease responsible for?
20%
What are some renal diseases that cause hypertension?
Chronic pyelonephritis
Fibromuscular dysplasia
Renal artery stenosis
Polycystic kidneys
What are some causes of drug-induced hypertension?
NSAIDs
OCP
Corticosteroids
What condition in pregnancy can cause hypertension?
Pre-eclampsia
What are some endocrine causes of hypertension?
Cushing's disease Conn's syndrome Phaeochromocytoma Hypothyroidism Hyperthyroidism Acromegaly
What is a vascular cause of hypertension?
Coarctation on the aorta
Hypertension is the world’s number one cause of preventable mortality and morbidity, and the UK’s number one cause of premature morbidity and mortality. What is the risk of heart disease and stroke mortality with hypertension?
For a 2mmHg rise in BP there is a 7% increased risk of mortality from heart disease and a 10% increased risk of mortality from stroke
What are some of the factors which increase the risk from hypertension?
Cigarette smoking Diabetes mellitus Renal disease Male Hyperlipidaemia Previous MI or stroke Left ventricular hypertrophy
What are some factors that affect the development of hypertension?
Age Genetics Family history Environment Weight Alcohol intake Race
How does BP change with age?
Tends to rise with age
How should hypertension be treated in the elderly?
As aggressively as possible - studies show benefit from treating both systolic and diastolic hypertension
Why are genetics/family history considered to be risk factors for hypertension?
Hypertension tends to run in families with the closest correlation between siblings
Genes have been recognised as important in development of hypertension
Possible that environmental factors common to all members of a family have a role in the development of hypertension
How do mental and physical stress affect BP?
Both increase BP
How do people with white coat hypertension tend to respond to treatment?
Tend to be highly resistant to treatment
What effect can reducing salt intake in hypertensive individuals have?
Lowers BP
What salt reduction is necessary to lower BP?
Reducing salt intake to < 6 grams per day or to 1.5 gram/day
What is one of the most common causes of hypertension in young people?
Alcohol
What effect does alcohol have on BP?
Small amounts tend to decrease it but large amounts tend to increase it
What is the average fall in BP with alcohol consumption reduction?
Around 5/3 mmHg
How does weight affect BP?
Increases with weight
Obese patients have higher BP
What percentage of hypertension is attributable to obesity?
30%
What is the association between weight loss and BP reduction?
In non-medically treated patients, weight loss of 9kg has been reported to produce fall in BP of 19/18mmHg
In medically treated patients a fall of 30/21 mmHg has been reported
What is the most important non-pharmacological measure in hypertension treatment?
Weight loss
How is birth weight associated with hypertension?
Lower the birthweight, higher the likelihood of developing hypertension and heart disease in later life
How does race affect BP?
Caucasians have a lower BP than black populations living in the same environment
What are the potential complications of hypertension (end organ damage)?
Haemorrhage, stroke, cognitive decline
Retinopathy
Peripheral vascular disease
Left ventricular hypertrophy, coronary heart disease, congestive heart failure, MI
Renal failure, dialysis, transplantation, proteinuria
What percentage of strokes are attributable to BP greater than 140mmHg?
40%
What are the prime contributors to BP?
Cardiac output
Stroke volume
Heart rate
Peripheral vascular resistance
