Systemic hypertension

 

Systemic hypertension is defined medically as a blood pressure greater than 140 / 90 mmHg.

Pathology

Causes

1. essential hypertension : 95 % : idiopathic
2. secondary hypertension : 5 % : underlying cause identified

Causes of secondary hypertension :

• renal
  • acute glomerulopathies
  • chronic renal failure
  • renal artery stenosis
  • renin producing tumour
• adrenal
  • Cushing's syndrome
  • primary hyperaldosteronism
  • congenital adrenal hyperplasia
  • phaeochromocytoma
• other endocrine
  • thyroid dysfunction (hyper or hypothyroidism)
  • acromegaly
• vascular
  • aortic coarctation
  • vasculitis
• neurogenic
  • psychogenic
  • raised ICP
  • severe physiological stress (eg. surgery)
• pregnancy
  • pregancy-induced hypertension (pre-eclampsia)
• drugs
  • steroid use
  • adrenergic drugs
  • illicit drug use :  cocaine, amphetamines

Risk factors

• increasing age
• obesity, lack of exercise
• high salt diet
• alcohol, smoking
• stress
• genetic factors, family history
• secondary causes listed above

Presentation

• usually asymptomatic
• may present with complications (see below)

Complications

• accelerated atherosclerosis : esp. ischaemic heart disease, stroke, peripheral vascular disease
• left ventricular hypertrophy, diastolic dysfunction (due to increased afterload)
• aortic dissection (due to medial degeneration)
• Intracerebral haemorrhage (due to medial degeneration, Charcot-Bouchard aneurysms)
• lacunar infarcts, deep white matter ischaemia (due to hyaline arteriolosclerosis)
• chronic renal impairment (due to hyaline arteriolosclerosis)
• malignant hypertension

Malignant (accelerated) hypertension

Defined as rapid rise in blood pressure to greater than 200/120 mmHg. May occur on a background of pre existing hypertension or as first manifestation of hypertension. High mortality if untreated. Associated with hyperplastic arteriolosclerosis, renal failure, retinal haemorrhages and exudates, papilloedema, headache and seizures.

Management

• modification of lifestyle factors
• antihypertensive medication
• treat underlying causes
• treat complications