Pathology of hypertension Flashcards
Hypertension is a risk factor for …
cerebral haemorrhage
atheroma
renal failure
sudden cardiac death
How is hypertension classified?
Primary (no other cause) or secondary (other cause) and benign (presents routinely) or malignant (presents as part of a medical emergency)
What affects the peripheral resistance?
- constrictors e.g. angiotensin II
- dilators e.g. nitric oxide & prostagladins
Primary hypertension’s characteristics
- genetic factors
- no obvious cause
- 25% of primary hypertension is sensitive to salt
- Affected by the RAAS and sympathetic activity
Salt sensitive hypertension
- increase in dietary salt leads to increased BP with certain genetic polymorphisms
- some cases of primary hypertension
- controlled by reduced salt diet
- in renal disease secondary hypertension is usually salt sensitive
underlying diseases which can cause secondary hypertension
Renal disease Endocrine disease Aortic disease (coarctation of the aorta, congenital narrowing of the segments of the aorta - in infants) Renal artery stenosis Drug therapy (including corticosteroids)
Renal causes of secondary hypertension
- any renal disease causing
- reduced renal blood flow
- excess renin release
- salt and water overload
Endocrine causes
Adrenal gland hyperfunction - tumours
Conn’s syndrome (excess alsosterone)
Cushing’s syndrome (excess corticosteroid)
Phaeochromocytoma (excess noradrenaline)
Benign hypertension
a cause of serious life threatening morbidity however it is asymptomatic and so is normally an incidental finding at health checks
Benign hypertension will eventually cause
Left ventricular hypertrophy Congestive cardiac failure Increases atheroma Increases aneurysm rupture - aortic dissection, Berry aneurysms
Renal disease
What are the affects of left ventricular hypertrophy?
Increased LV load poor perfusion of the tissue interstitial fibrosis micro-infarcts diastolic dysfunction
What can left ventricular failure lead to?
right ventricular failure making it bilateral heart failure
What are the potential complications of of benign hypertension?
left ventricular failure complicated atheroma aortic dissection stroke subarachnoid haemorrhage
What are the potential effects of left ventricular hypertrophy?
sudden cardiac death - arrhythmia and poor perfusion
cardiac failure
affects the outcome of other disease
What is the correlation between the amount of the raised benign hypertension and the increased risk of event?
Every 10mmHg of diastolic pressure above 85 doubles risk of MI
Every 8mmHg of diastolic pressure above 85 doubles risk of stroke
