L15 - Hypertension Flashcards
What does blood pressure increase naturally with?
Age and in males
What are the normal blood pressures during diastole?
Normal BP - <85 High normal BP – 85-89 Mild hypertension – 90-104 Moderate hypertension – 105-114 Severe hypertension - >114
What are the normal blood pressures during systole?
Normal BP - <140
Systolic hypertension – 140-159
Isolate systolic hypertension - >160
How do you calculate mean arterial blood pressure?
Mean arterial blood pressure = cardiac output x total peripheral resistance
Cardiac output decreases with age
Total peripheral resistance increases with age – arteries stiffen
What are the symptoms of essential hypertension?
Cardiac dysfunction
Vessel abnormalities
Kidney dysfunction
What is cardiac dysfunction? - essential hypertension
Have increased response to stress and catecholamines
What are vessel abnormalities? - essential hypertension
Sympathetic nervous system abnormalities Local factors - Low nitric oxide (EDRF) - Smooth muscle ion channel defects Muscle hypertrophy and rigidity
What is kidney dysfunction? - essential hypertension
Issues controlling volume – induced hypertension
What are the genetic factor of essential hypertension?
30-50% of population have a genetic predisposition
5 different genes - best evidence for polymorphisms in
- Angiotensinogen
- ENaC
Varies with race
- Higher among African-Caribbean
What are the environmental risk factors of essential hypertension?
Diet (high salt) and obesity (metabolic syndrome)
Western lifestyle
Vitamin D deficiency
What clinical conditions can secondary hypertension be the consequence of?
Renal disease
Renal artery stenosis
Hormone imbalance
Secondary hypertension - renal disease
Nephron function impaired
Blood volume and blood pressure increase
Leads to more damage and kidney failure
Secondary hypertension - renal artery stenosis
Narrowing of renal arteries
Renin production and increased blood pressure
Secondary hypertension - hormone imbalance
Aldosterone increases Na and increased blood pressure
Mini adrenal tumours
What is the link between high salt and hypertension?
Single mutation in blood pressure diseases increases or decreases HIT Na uptake
What is the link between high salt and hypertension? - animal and human models
Animal studies
- Models such as Chimpanzees
Human studies
- Reduce salt by 3g/day
- Reduced mean arterial blood pressure by 5mm Hg
- Equivalent to a drug that reduces strokes
What are the consequences of hypertension?
Flushing and sweating
Blurred vision
Arteriosclerosis - hardening of the arteries
Atherosclerosis - deposition of cholesterol plaques
Aneurysms – aortic diameter increases by 2-8 cm
Stroke - high systolic with bleeding or thrombosis
Myocardial infarction
Retinal damage – hypertensive retinopathy
- Hard to tell difference between arterioles and venules so fundoscopic examination inconclusive
What are the 4 different treatments for hypertension?
Non-pharmacological
Pharmacological
RAA system
Dual approach
Treatments for hypertension - non pharmalogical
Weight loss Exercise Diet – salt, alcohol, caffeine Smoking Relaxation
Treatments for hypertension - pharmalogical - what are the 3 types?
Diuretics
Sympatholytics
Ca channel blockers
Treatments for hypertension - diuretics
Thiazides – increase Na and Cl excretion
Treatments for hypertension - sympatholytics
Alpha blockers
- Clonidine - decreases CNS sympathetic output
- Prazosin – relaxes smooth muscle and decreases total peripheral resistance
Beta blockers
- Propranolol – decreases heart rate and contractility
Treatments for hypertension - Ca channel blockers
Broad spectrum - Minoxidil – decreases cardiac contractility and vascular muscle Selective - Manidipine - Vascular muscle
Treatments for hypertension - RAA system
ACE inhibitors – moexipril
Angiotensin II receptor blockers – sartan family
Treatments for hypertension - dual approach
Diuretic and something else
