Hypertension Flashcards
What criteria determines the definition of hypertension?
HTN coincides with a level of BP above which the benefits of treatment outweigh side effects (this is a population definition; detecting and treating HTN will benefit individuals)
What polygenic factors influence risk of primary HTN?
Genes for sympathetic hyperactivity, renin activation and susceptibility to salt
What multi-environmental factors influence risk of primary HTN?
Obesity
Excess salt (especially in elderly)
Alcohol
How can salt be reduced in the diet?
Added salt
Processed foods
Prepared meals (i.e. fast food)
In what % of HTN is a specific cause identified?
5%
List 5 causes of secondary HTN
Kidney disease (acute or chronic)
Renovascular disease (e.g. renal artery stenosis)
Coarctation of the aorta
Endocrine causes (e.g. adrenal tumours secreting aldosterone/cortisol/catecholamines, OCP, HRT)
Sleep apnoea
OR ABCDE
Apnoea and aldosterone (Conn’s or secondary)
Bruit (renal artery stenosis) or bad kidneys (AKI or CKD)
Calcaemia (hyper), Cushings, Catecholamines, Coarctation
Drugs (NSAIDs, alcohol, steroids, lithium, cocaine, amphetamines, OCP, MAOIs)
Endocrine (hyperthyroid, hypothyroid, hyperPTH because of hypercalcaemia, etc)
When is a large arm cuff for measuring BP indicated?
If arm circumference >32cm (but don’t overestimate effect of using small cuff - should only elevate BP by a couple of mmHg)
What is the current criteria for diagnosis of HTN?
BP >140/90 mmHg (>135/85 mmHg if comorbidities e.g. DM, CKD, etc)
After 5 minutes seated rest
2 readings, 2 mins apart
How can an initial diagnosis of HTN be confirmed?
Additional visit in 1-4 weeks
Can also use 24-hour ambulatory measurements (in which case criteria is day-time >135/85 mmHg; you add 10mmHg for in-clinic BP) or home BP measures
When might isolated systolic HTN occur?
Generally reflects high pulse pressure (with relatively low DBP) seen in aged and stiff arteries
What routine tests should be ordered on diagnosis of HTN? Why?
FBE: associated anaemia of CKD
UEC: plasma K+ (high in renal disease, low in aldosteronism) and creatinine (high in renal disease)
Urine albumin/creatinine ratio: may be evidence of renal damage
LFTs: may be associated fatty liver or drug reaction
Fasting glucose: may be associated glucose intolerance
Fasting lipids: may be associated CV risk
MSU: clues as to causes of possible renal disease
ECG, echo: to detect coronary disease and cardiac hypertrophy
What % of patients in the general population have masked HTN?
10%
When should masked HTN be suspected?
In patients with evidence of end-organ damage but normal clinic BP readings
Define nocturnal nondipping
Decrease of less than 10% in average night-time SBP and/or DBP compared with day-time averages
What does nocturnal nondipping suggest mechanistically?
End-organ damage
Autonomic dysfunction
OSA
When might plasma K+ and creatinine be elevated in a case of HTN?
In the context of renal disease
When might plasma K+ and creatinine be low in a case of HTN?
In the setting of aldosteronism
6 Framingham CV risk factors
Age and gender HTN Smoking DM Hyperlipidaemia Previous stroke/MI
What underlying secondary causes should be considered in the patient with HTN?
Pregnancy
OSA
Falls Hx and risks
Rx Hx
What is the relationship between blood pressure and risk of major CV and stroke events?
Above 115/75 mmHg, for each increase of 20 mmHg in SBP the risk of major CV and stroke events doubles
Give 5 examples of diseases high BP predisposes to
Coronary heart disease Stroke Cardiac hypertrophy HF Kidney failure
What is the prevention paradox?
Majority of deaths attributable to BP occur in people with “normal BP”. Modest risk in many with average BP accounts for more deaths than high risk in severe hypertensives
What is the public health prevention principal related to HTN?
Reducing the community average BP is good for the community
What is the benefit of using a semiautomated manometer to measure BP?
Avoids observer error
