Cardio L14 Hypertension Flashcards
Hypertension: Definition
Diastolic (and systolic) blood pressures vary widely in the population and show a normal distribution.
Hypertension: Prevalence
20% of adults
Isolated Systolic Hypertension
Isolated elevation in systolic pressure alone with normal diastolic pressures. Common in the elderly and is predominantly due to increased stiffness/reduced compliance of the large blood vessels including the aorta.
White Coat Hypertension
Rise in Blood pressure while being examined by a physician e.g. fight or flight response.
Primary (essential) Hypertension
95% of cases, no cause identified.
Secondary Hypertension
2-5% of cases with a defined underlying cause.
Uncommon but important because it may be curable.
Hypertension Symptoms
- The majority of hypertensive patients are asymptomatic and it is discovered during a routine physical examination.
- The “classic” symptoms of headache and nosebleeds do not appear to occur more frequently than in the general population, except in very severe hypertension.
Signs of hypertension
- High BP
- Signs due to organ damage
- There may be signs due to the underlying cause in secondary hypertension.
Organ damage: from hypertension Brain Symptoms:
- Longstanding hypertension leads to microaneurysms that may rupture to cause haemorrhagic strokes (CVE, CVA)
- Atherosclerotic plaques may embolise or cause thrombosis resulting in a cerebral infarct.
- Occlusion of small penetrating branches may result in multiple tiny infarcts resulting in cavities known as lacunae.
Heart effects froms hypertension
- Left ventricular hypertrophy in responding to chronic elevation of afterload that may lead to congestive cardiac failure.
- Accelerated coronary atherosclerosis predisposing to ischemia and infarction.
Aorta and peripheral vasculature damage from hypertension
- Peripheral vascular disease
- Abdominal aortic aneurysm “tripe A” >6cm
- Aortic dissection
Kidney symptoms from hypertension
Produces nephrosclerosis, which in severe hypertension may lead to a leak of protein into urine (proteinuria) and chronic renal failure.
Retina damage form hypertension
- Only location where arteries can be directly visualised using an opthalmoscope.
- The changes depend upon the severity and duration of the elevated blood pressure (grades I-IV)
Suspicion of Secondary Hypertension:
- Young age onset (180/110)
- Signs of underlying pathology
- Sporadic (i.e. no history in history degree relatives)
- Refractory to drug treatment.
Causes of secondary hypertension
- Renal (Chronic Failure, Renal Artery stenosis)
- Mechanical (coarctation of the aorta)
- Endocrine (Conn’s Sundrome, Cushing’s syndrome, Phaeochromocytoma, Acromegaly, thyroxtoxicosis)
- Drugs (e.g. oral contraceptive)
- Pre-eclamptic toxaemia
Renal artery stenosis
- Atherosclerosis in elderly man
- Fibromuscular dysplasia in young woman
- Abdominal bruit
- Activation of RAA system results in hypokalaemia
- Goldblatts experiment
Coarctation of the Aorta
- Congenital narrowing often distal to origin of left subclavian
- BP in arms > legs
- Weak or absent femoral pulses
- Midsystolic murmur between scapulae
- Notched appearance of ribs on CXR due to shunting of blood through enlarged arteries
Conn’s Syndrome
- Adrenal tumour (adenoma
- Often asymptomatic
- Produces Hypokalaemia