3.1.1 Hypertension Flashcards
What is BP?
Driving force to perfuse organs with blood
Force per unit area acting on vessels, not uniform throughout body
How do you calculate mean arterial blood pressure (MAP)?
DBP + (SBP-DBP)/3
What is blood pressure regulated by?
Autonomic sympathetic
Blood pressure detected by baroreceptors
Decreased RBF and GFR
What receptors lead to an increased BP?
B1 adrenoceptors on heart- increased CO
A1 adrenoceptors on smooth muscle- increased venous return and peripheral resistance
A1 adrenoceptors on kidney- renin
What is an autocoid?
Molecules that can act as a hormone locally
Give two examples of autocoids
Bradykinin
Nitric oxide
Both vasodilators
What has the greatest effect on BP?
Resistance
This is controlled by smooth muscle, as the lumen changes size, resistance changes
Explain the pathophysiology which elevated BP leads to
Elevated blood pressure leads to vascular changes, remodelling, thickening and hypertrophy
Increased vasoactive substances, Endothelin-1 (potent vasoconstrictor), NorAd, AngII
Vascular remodelling occurs due to local salt sensitivity
Hyperinsulinaemia and hyperglycaemia lead to endothelial dysfunction and increased reactive oxygen species, NO signalling reduced
What does elevated blood pressure cause long-term?
Permanent and maintained medial hypertrophy of vasculature with increased TPR and decreased compliance of vessels
End organ damage, renal, aneurysm, vascular demential, retinal disease
LVH leads to dilated cardiac failure
Increased morbidity and mortality
Why is it difficult to get patients to adhere to hypertension treatments?
Hypertension is asymptomatic, if a patient notices no change but has to medication with side effects, they’re not as happy to do so and less likely to adhere
What is the definition of hypertension?
Elevated BP that can cause organ damage
> =140/90 mmHg
What is hypertension caused by?
90% is idiopathic
10% is caused by:
-Secondary hypertension to other pathology
-Pre-hypertension
-Isolated systolic/diastolic hypertension
-White coat (can be upto 50mmHg, increases due to stress from being in Drs)
What should be done to raise awareness of hypertension?
- Screen those at risk
- Increase public awareness of risk factors
- Lifestyle changes to limit risk
Silent killer, need to make people aware
What should be done when diagnosing hypertension?
- Take reliable measurements based on clinical guidelines
- Regular monitoring and refine medication once started
What is best practise to take BP for diagnosis?
- Sitting, relaxed and arm supported
- Both arms should be within 15mmHg, if not repeat
- Use arm with higher reading
- Measure over a period of multiple visits, ambulatory (patient wheres cuff at home or takes readings at home)
- Check for end organ damage and CVD risk while waiting for hypertension confirmation
What are the different BP targets?
120/80 is ideal
What are the 3 stages of hypertension?
