Introduction
risk factors for hypertension
secondary causes of hypertension
initial Dx of hypertension
initial Ix of newly diagnosed hypertension
initial Rx of hypertension without end organ damage
Mx of asymptomatic high BP in the ED
urgent reduction of blood pressure in the ED in hypertensive "emergency"
- parenteral Rx in resus setting with close haemodynamic monitoring
- oral Rx when Rx is less urgent
podcasts and other references

hypertension

Introduction

it is important that BP be measured correctly:
- cuff should be at the level of the heart
- cuff should be the correct size for the patient
- arm should be resting on a desk - arm resting on the lap or unsupported gives BP readings 4-9mmHg higher ¹⁾
- consider measuring BOTH arms in case there is a difference due to anatomy (or rarely a type B aortic dissection)
- when assessing for Rx of hypertension, it should be done when the patient is relaxed and not anxious and repeated over days or weeks to confirm

risk factors for hypertension

older age
obesity
genetics:
- 2x risk if parent has HT, higher incidence in those of African descent
- rare familial causes:
  - hypertension and brachydactyly (HTNB) syndrome (Bilginturan syndrome) due to a faulty, over-active form of phosphodiesterase 3A (PDE3A) ²⁾
chronic exposure to air pollution particulate matter ³⁾⁴⁾
high sodium diet
high tellurium levels from food contamination ⁵⁾
high alcohol intake
sedentary lifestyle
diabetes
personality traits
depression
? role of T_EM cells activated by CD70 on Antigen Presenting Cells:⁶⁾
- these memory cells can be long lived, lasting decades, and reside in the bone marrow and can potentially sensitize the host to repeated mild hypertensive stimuli and may play a critical role in salt-sensitive and angiotensin II–induced hypertension
- these cells are major sources of IL-17A and IFN-γ, which are thought to be prime mediators of hypertension
- recurrent hypertensive stimuli which appear to activate CD70 and T_EM cells include:
  - emotional stress
  - catecholamine surges in sleep apnea
  - repeated bouts of excess sodium intake

secondary causes of hypertension

medications such as:
- combined oral contraceptive pill (OCP)
- non-steroidal anti-inflammatory drugs (NSAIDs)
- antidepressants
- corticosteroids
- sympathomimetics such as pseudoephedrine, amphetamines, cocaine
renal disease
renovascular disease
primary hyperaldosteronism ⇒ hypokalaemia, metabolic alkalosis
- eg. daily transient adrenal adenoma hyper-aldosteronism
  - discovered in 2023 ⁷⁾
    - generally requires 24hr urine aldosterone to detect as serum levels may miss the transient rises
    - caused by a somatic mutation in aldosterone-producing adenomas of the gene which produces a protein called CADM1
    - seems to the the cause of 5-10% of cases of hypertension
    - Rx is unilateral adrenalectomy
obstructive sleep apnoea
Cushing's syndrome
phaeochromocytoma
coarctation aorta
possibly, but unproven:
- cervical spondylosis / cervical disc prolapse (often also causes vertigo, headaches which are not due to vertebrobasilar insufficiency from cervical disease, but perhaps due to stimulation of sympathetic nerve fibres around the proximal vertebral artery or perhaps due to pain)
  - see https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4602471/
- chronic pain syndromes

initial Dx of hypertension

if no end organ damage evident, Dx is usually best made on at least 3 BP checks over a period of weeks and taking into consideration white coat false positive BP values
caffeine intake in the 0.5-4hrs prior to measurement may increase systolic BP 3-15mmHg, and diastolic BP 4-13mmHg and this needs to be taken into account, and the hypertensive effect seems greatest in males with stage 1 hypertension ⁸⁾ ⁹⁾
BP should be similar in both arms and if more than 15mmHg, one should suspect subclavian stenosis and peripheral vascular disease (PVD or PAD), or in the context of chest pain, the life threatening emergency of aortic dissection
in the adult:
- Stage 1 hypertension = systolic 140 to 159 mmHg or diastolic 90 to 99 mmHg
- Stage 2 hypertension = systolic ≥160 mmHg or diastolic ≥100 mmHg

initial Ix of newly diagnosed hypertension

assess end organ damage:

CXR, ECG, U&E, urinalysis
fundus exam for retinopathy
if evidence of cardiac failure, LV dysfunction, then consider echocardiogram
consider a random timed urine albumin-to-creatinine ratio

assess potential life style modifications:

see below

assess other risk factors:

fasting lipids, glucose
urine albumin and creatinine (urine ACR)
plasma aldosterone-to-renin ratio test indications now include stage 2 hypertension, resistant hypertension or obstructive sleep apnoea (OSA)
- continue most antihypertensive medications (other than MRA) prior to initial screening to minimize barriers to or delays in screening

consider targeted approach to excluding secondary causes in subgroup of:

prepubertal onset
age < 30 with no overt risk factors
presentation in Stage 2
severe HT (> 180/120 mmHg) at age > 55yrs or with small kidney (<9cm or > 1.5cm smaller than other kidney)
acute rise in BP or malignant HT
renal impairment with sustained rise of > 50% in serum CRN after starting ACE inhibitors
resistant hypertension
flash acute pulmonary oedema (APO) ⇒ ?renovascular
paroxysmal high BP ⇒ phaeochromocytoma
hypokalaemia ⇒ ? aldosteronism
abdominal bruit ⇒ ? renovascular
Cushingoid
sleep apnoea risk
brachio-femoral delay ⇒ ? coarctation
renal impairment or abnormal urinalysis

initial Rx of hypertension without end organ damage

life style modifications
- sodium restriction to 2300 mg per day, moving toward an ideal limit of 1500 mg per day by checking food labels
- in adults with or without hypertension, potassium-based salt substitutes can be useful to prevent or treat elevated BP and hypertension, particularly for patients in whom salt intake is related mostly to food preparation or flavoring at home, except in the presence of CKD or use of drugs that reduce potassium excretion where additional monitoring is probably indicated.
- weight loss gives 0.5-2mmHg reduction per kg lost
- cut down on caffeine intake to 2 cups/day - although this measure was not included in 2025 AHA guideline
- avoid sympathomimetic agents such as pseudoephedrine
- DASH diet gives additive benefits to modest sodium restriction
- ideally, consuming no alcohol or for those who choose to drink, consuming no more than two drinks per day for men and no more than one drink per day for women
- increase aerobic exercise to 75-150min/week may reduce BP by ~4mmHg
- ensure at least 6hrs sleep each night as long term sleep deprivation increases risk of hypertension
- cease smoking to avoid the compounding effects on atherosclerosis
- managing stress with exercise, as well as incorporating stress-reduction techniques
- home blood pressure monitoring is recommended for patients to help confirm office diagnosis of high blood pressure and to monitor, track progress and tailor care as part of an integrated care plan
initial pharmacologic Rx:
- if diabetic or proteinuria > 30mg/g or eGFR < 60 then ACE inhibitors or angiotensin II receptor blockers (ARBs)
- if ischaemic heart disease or other compelling reason, then beta adrenergic blockers
- if black or African American, then diuretic or long acting calcium blocker
  - ACE inhibitors are less potent and less effective in lowering blood pressure in black adults compared to white patients due to lower renin levels and higher salt sensitivity, genetic polymorphisms in the angiotensinogen gene, and differences in how the intrarenal renin-angiotensin system responds to salt intake
- if BP > 20/10mmHg above goal then consider ACE inhibitors + long acting calcium blocker
- all adults with stage 2 hypertension, the initiation of antihypertensive drug therapy with 2 first-line agents of different classes in a single-pill, fixed-dose combination is preferred over 2 separate pills to improve adherence and reduce time to achieve blood pressure control2025 AHA hypertension guidelines

US targets

as of 2025 AHA

see 2025 AHA hypertension guidelines
most people should have a target BP of < 130/80 to reduce cognitive decline
use the PREVENT^TM risk calculator to estimate a person's risk of a heart attack, stroke or heart failure
adults with average BP > 130/80 without CVD:
- with diabetes, CKD, PH stroke, clinical cardiovascular disease or at increased 10-year CVD risk (ie, ≥7.5% based on PREVENT^TM)
  - initiation of medications to lower BP is recommended when average SBP is ≥130 mm Hg and average DBP is ≥80 mm Hg to reduce the risk of CVD events and total mortality
- if estimated 10-year CVD risk <7.5% based on PREVENT^TM:
  - initiation of medications to lower BP is recommended if:
    - average blood pressure ≥140/90 mm Hg, or,
    - average SBP remains ≥130 mm Hg or average DBP remains ≥80 mm Hg after a 3- to 6-month trial of lifestyle intervention to prevent target organ damage and mitigate further increases in BP.

Mx of asymptomatic high BP in the ED

this group of patients are those who:
- are not pregnant (see pre-eclampsia and eclampsia),
- not on dialysis,
- do not have an acute stroke or intracranial haemorrhage,
- are not being admitted for cardiac conditions, and,
- do not have overt evidence of acute end-organ complications:
  - hypertensive encephalopathy
  - acute renal impairment
  - aortic dissection
  - angina
  - acute pulmonary oedema (APO)
they thus do NOT need Ix in ED
- ECG, CXR, blood tests are NOT needed in the ED - they can be arranged as OP by LMO
they also do NOT need urgent Rx in ED
- see AHA 2025 hypertension guidelines
- rest is generally as good as acute Rx

AHA 2025 Guidelines: for non-pregnant non-stroke adults with severe hypertension (>180/120 mm Hg) who are hospitalized for non-cardiac conditions without evidence of acute target organ damage, intermittent use of additional intravenous or oral antihypertensive medications are NOT recommended to acutely reduce BP!¹⁰⁾
- these patients should be evaluated and treated in the outpatient setting with initiation, re-institution, or intensification of oral antihypertensive medications in a timely manner

urgent reduction of blood pressure in the ED in hypertensive "emergency"

usually indicated if severe HT with diastolic > 120mmHg with end organ affects
may be indicated with other conditions where high BP is not desirable
see also pre-eclampsia and eclampsia for Mx in pregnancy
see sudden transient surges in BP
acute spontaneous intracranial haemorrhage
- careful titration to ensure smooth, non-labile, and sustained control of BP, avoiding peaks and large variability in SBP, can be beneficial for improving functional outcomes¹¹⁾
acute ischaemic stroke
- in patients undergoing successful brain reperfusion with endovascular treatment for a large vessel occlusion, lowering SBP <140 mm Hg within the first 24 to 72 hours after reperfusion can worsen long-term functional outcome! ¹²⁾

parenteral Rx in resus setting with close haemodynamic monitoring

if there is encephalopathy, see posterior reversible encephalopathy syndrome (PRES) as iv labetalol may be the preferred Rx
otherwise, consider:
- sodium nitroprusside 0.3 microgram/kg/minute IV for 10 minutes, then increasing or decreasing by 0.3 microgram/kg/minute every 5 to 10 minutes (up to a maximum of 10 micrograms/kg/minute), or,
- hydralazine 5 to 10 mg slowly IV, repeating at 20 minute intervals if necessary, or,
- GTN infusion