Cardiology vasculature

Vascular disease

Atherosclerosis

Atherosclerosis is narrowing and hardening of the arterial wall by a build-up of lipids and fibrous
materials to form a plaque. The arterial endothelium in the wall becomes damaged by high BP, DM
and smoking which allows the plaque to form. The plaque can block blood flow and lead to strokes,
organ failure or a heart attack.

This is more likely to affect the larger and high pressured vessels such as:

 Coronary
 Renal
 Femoral
 Cerebral
 Carotid

Peripheral arterial disease is narrowing of the arteries in the legs caused by a plaque. Coronary artery
disease is when stable plaques form in the heart’s arteries causing angina. When this stable plaque
suddenly ruptures and clothing begins, the heart muscles begins to die causing an MI.
Cerebrovascular disease is ruptured plaques in the brains arteries causing strokes with the potential
for permanent brain damage. Temporary blockages in an artery can also cause TIAs.

There are 2 types of plaques; stable which are asymptomatic and unstable. Stable ones are when
there is plaque formation but no rupturing and no accumulation of platelets. The unstable ones are
rich in macrophages and foam cells. The extracellular matrix separating the plaque from the arterial
lumen is usually weak and prone to rupture. The rupture exposures thrombogenic material, such as
collagen to the circulation and eventually induces thrombus formation in the lumen i.e. a clot.

Atherosclerosis causes an occlusive arterial event. This is when the blood flow is reduced or blocked
in an artery. When an artery becomes occluded, these events can occur:

 Ischemic stroke
 TIA
 MI
 Acute leg ischemia

With unstable plaques that rupture, platelets begin to accumulate and aggregate. In the beginning,
when the platelets begin to gather, this only partially blocks the artery causing unstable angina.
When a thrombus comes along and binds, further blocking the artery, this causes a NSTEMI. When
the thrombus completely blocks the artery, this causes a STEMI. Once an artery becomes occluded,
tissue death (infarction) occurs within 5 minutes. Death can occur within an hour of symptom onset.

Triggers for plaque rupture:

 Physical exertion
 Pulse rate
 Blood pressure
 Vasoconstriction

Risk factors:

 Modifiable

, o Diabetes or impaired glucose tolerance
o Hyperlipidaemia
o Hypertension
o Smoking
 Non-modifiable
o Advanced age
o Male gender
o Family history
o Genetic abnormalities
 Others
o Hypercoagulability
o Post menopause
o Hyperthyroidism
o Sleep disorders

Symptoms:

 Chest pain
 SOB – worst on exertion
 Peripheral vascular disease
o Pallor/cyanosis
o Skin ulcers
o Muscle weakness
o Confusion

Investigations:

 FBC, U&E, HbA1c and lipid profile
 Ankle-brachial index
o Tells us if you have it in your legs and feet
o Abnormal difference may indicate peripheral vascular disease
 ECG
 US if peripheral vascular disease is suspected

Treatment:

 Acute
o Percutaneous coronary intervention (PCI) e.g. stent
o CABG
o Thrombolysis e.g. alteplase
 Medications
o Calcium channel blockers e.g. amlodipine
o Ace inhibitors e.g. lisinopril
o Beta blockers e.g. bisoprolol
o Antiplatelets e.g. aspirin
 Prevention
o Statins e.g. atorvastatin

Peripheral arterial disease (PAD)