Coronary Artery Disease Flashcards
Understand the burden of coronary artery disease Describe the underlying pathology in coronary artery disease Describe clinical symptoms and signs that are associated with coronary artery disease Describe the mechanism of action of drugs used to treat or prevent coronary artery disease
What is the difference between coronary artery disease and coronary heart disease?
No difference, interchangeable terms
What is the basic mechanism of coronary artery disease?
Waxy plaque substance forms on the inside of an artery and builds up overtime to eventually narrow the artery restricting blood flow and hence oxygen
What are the 4 types of cardiovascular disease?
Coronary heart disease
Strokes and TIA’s (transient ischemic attacks)
Peripheral arterial disease
Aortic disease
What is the function of coronary circulation?
To supply oxygen rich and nutrient rich blood to the heart, ensuring the myocardium has adequate oxygen for all levels of cardiac activity
What are the 2 main consequences of coronary artery disease?
Angina
Myocardial Infarction
What types of lesions can coronary artery disease produce?
Stenotic and non-stenotic
What are the difference between stenotic and non-stenotic lesions?
Stenotic - fewer of them, fibrotic, thick cap produce less compensatory enlargement
Non-stenotic - many of them, lipid rich, thin cap and produce compensatory enlargement
What is the first stage of coronary artery disease from a normal artery?
Endothelial dysfunction -> infiltration & oxidisation of LDL deposits, monocyte infiltrates to engulf toxic LDL
How does a fatty streak form?
Monocytes swell, foam cells form and platelets stimulate SM growth producing a fatty streak (atheroma)
How does a vessel become partially occluded?
plaque grows over decades leading to narrowing of the coronary artery
How does a vessel become totally occluded?
Blood clot forms in the lumen and the lumen eventually collapses
What are the 7 stages to an atheroma formation?
Monocyte adhesion LDL oxidation Macrophage infiltration Foam cell formation Smooth muscle cell proliferation and migration Fibrous cap formation Plaque rupture and thrombus formation
What are the signs and symptoms of coronary artery disease?
Chest pain
Indigestion
Nausea & Vomiting
Fatigue & Sleep Problems
What are grade 1 symptoms of coronary artery disease?
chest pain only in response to sudden physical or emotional strain but not during everyday activities - walking/climbing stairs
What are grade 2 symptoms of coronary artery disease?
Chest pain during more intense activities like walking quickly, uphill, climbing stairs after eating, cold, emotionally stressed
What are grade 3 symptoms of coronary artery disease?
Chest pain even during low-intensity physical exertion like walking or getting dressed
What are grade 4 symptoms of coronary artery disease?
Chest pain when at rest or during slightest physical exertion
How is coronary artery disease diagnosed?
ECG Stress test angiography Echocardiography Blood tests - troponin
What are the 3 stages of coronary artery disease treatment?
First line - preventative
early stage - management
late stage - intervention
What does first line therapy involve?
lipid lowering
lower blood pressure
lifestyle changes
What does early stage management involve?
Medical therapy:
beta blockers
ACE inhibitors
nitroglycerin
What does late stage intervention involve?
mechanical revascularisation:
cardiac bypass
percutaneous coronary intervention
What are the most common drugs used in angina pectoris? (stable angina)
Vasodilators - nitrates, calcium blockers
Cardiac depressants - beta blockers, calcium blockers
What are the side effects of NTG?
headache
dizziness
reflex tachycardia
What are the side effects of beta blockers?
end diastolic volume increases
ejection time increases
What are the side effects of calcium channel blockers?
constipation
dizziness
AVN/SAN depressin
What is coronary artery angioplasty?
1 - build up of cholesterol partially blocking flow through artery
2 - stent with balloon inserted into partially blocked artery
3 - balloon inflated to expand stent
4 - balloon removed from expanded stent
What is the difference between MI and angina?
MI involves death of myocardial cells as there is significant lack of oxygen supply however angina may not lead to death of cells but just damage as lack of oxygen may not be as significant
What type of lesion is more prone to rupture?
Non-stenotic
What is present at all stages of atheroma formation?
Inflammation
How is inflammation so significant?
Infiltration of cytokines and chemokines means activation of more immune cells = inflammatory cascade = plaque progression
What do cardiac enzymes tell you?
Indicate cell death
What does a stress test tell you?
Where there is stable or unstable angina as at rest stable angina would mean there is no pain
What are some examples of statins?
Simvastatin, pravastatin, lovastatin
What do statins do?
Inhibit hMG co-A reductase which helps produce cholesterol intracellularly in the liver
Increases LDL receptor expression leading to metabolism of cholesterol rich LDL = lower plasmsa cholesterol levels
anti-inflammatory effect as low endothelial dysfunction
What do nitrates do?
At a low dose - vasodilation so decrease preload and therefore less stretching/contraction of heart and therefore less myocardial oxygen demand
At a high dose - afterload falls, dilation of coronary arteries, improved oxygen supply of myocardial cells, reduction of myocardial oxygen demand
What do beta blockers do?
Antagonising B1 receptors in heart, less contractility in ventricular myocardium so less oxygen demand, SAN heart rate lowers so less oxygen demand, blood pressure falls in arterioles
What are some examples of beta blockers?
Propanolol
Atenolol
What do CCB do?
Block calcium influx via voltage gated L-Type calcium channels
Reduce contractility of the heart
Reduce heart rate
Vasodilators in coronary arteries so greater oxygen supply
)are used to treat MI?
Beta blockers are first line therapy
If b blocker contraindicated - CCB (verapamil)
If poor response to B blocker add CCB so both
If poor response to both use long acting nitrate (ivabradine)
