DIS - Diseases of the Vasculature II: Ocular Vessel Disease - Week 9 Flashcards
Is the majority of hypertension insidious? What is it referred to as (2)? What is the mechanism and is the pressure rise generally acute or chronic?
Majority of hypertension is insidious (95%)
Referred to as essential or benign hypertension
Mechanisms poorly understood
Pressure rise is chronic
What percentage of hypertension is malignant/secondary? What is the pressure rise like and is it acute or chronic?
5% is malignant
Pressure rise is large and acute
In which does extensive retinopathy occur early, benign or malignant hypertension?
Malignant
What is hypertension defined as, both systolic and diastolic?
Systolic ≥160mmHg
Or diastolic ≥95mmHg
Arterial blood pressure is a product of what (2)?
Cardiac output and peripheral vascular resistance
Increase in either increases blood pressure
What is arteriosclerosis and why does it happen? What does it increase (2)? Can it lead to hypertension?
Stiffening of the arterial wall with age
-collagen deposition and smooth muscle cell hypertrophy
Increases peripheral resistance
Arteriosclerosis can lead to hypertension
Describe how fluid volume in blood may increase due to kidney function, what this causes (3) and what it may accelerate.
Fluid volume in blood increases due to decreased kidney function
-salt, diet, genes, etc
This causes increased cardiac output and peripheral vasospasm and sclerosis
Hypertension accelerates arteriosclerosis
What is the relationship between hypertension and arteriosclerosis?
Arteriosclerosis can lead to hypertension
Hypertension can accelerate arteriosclerosis
Are arterio/arteriolosclerosis associated with atheroma formation and vessel dissection?
Yes
What is the result of arterio/arteriolosclerosis (7)?
Stiffened/thickened wall Narrow arteriolar lumen Raised BP Vascular SM hypertrophy Collagen deposition Breakdown of elastin Endothelial dysfunction
What effect does increased blood pressure have on the endothelium (2) and how does this affect blood flow? What risk does this give (3)?
Endothelial damage and proliferation Causes turbulent blood flow -thrombus risk -local haemorrhage -local ischaemia
What effect does increased blood pressure have on gaseous exchange? Name one other factor that also contributes to this. What can this lead to?
Poorer gaseous exchange
- also thickened vascular wall (a consequence of increased blood pressure)
- can cause local ischaemia
What can happen to the vascular smooth muscle with increased blood pressure and what are four consequences of this?
Necrosis
Leads to local macrophage invasion, increasing the risk of thrombus formation
Can lead to lumen occlusion, resulting in localised/general ischaemia
Does high blood pressure cause poor capillary perfusion?
Yes
Are hypertension and arteriolosclerosis often clinically coincident or are they most seen in isolation?
Clinically coincident
List four clinical changes that can happen to the arteries in the retina with hypertension/arteriolosclerosis.
Arteriolar narrowing
-general or focal
Increased tortuosity of the vascular tree
Increased prominence of arteriolar reflex
Arteriolovenular crossing changes
List 5 stages of malignant hypertension by clinical appearance.
Haemorrhage Hard exudates Oedema Cotton wool spots Collaterals