Ischaemic Heart Disease Flashcards
What does atheroscleortic coronary disease cause?
- Chronic coronary insufficiency
- Angina
- Unstable coronary disease
- MI or sudeen ischaemic coronary death
- Heart failure
- arrythmia
- acute ischaemic
- Scar related
Epicardial
Outer surface of the heart
Endocardial =
inner surface of the heart
subendocardial region =
water-shed area of perfusion and first to become ischaemic
Types of coronary artery imaging in humans
- Coronary angiography
- CT
- MRI
What are the risk factors for atherosclerotic coronary artery disease?
- age
- hypertension
- hypercholestrolemia
- smoking
- diabetes
- obesity
- physical inactivity
Patholoy of an atherosclerotic plaque
- Fatty streak
- fibro-fatty plaue - fibrous cap forms over it
- Plaque distribution
- rupture
- corrosion
How do plaques form?
- Disturbance to the endothelium
- upregulation of adhesion molecules
- Traps monocytes and macrophages which sit in the sub endothelial layer
- uptake of oxidised LDL forming foam cells
- Foam cells released cytokines caused release of collagen
Symptoms of angina
- gripping central chest pain
- radiation to the arm, jaw and teeth
- clear and precise relationship to exercise
- worse after food and in the cold
- no autonomic fibres
- flat of hand/fist to describe pain
Cause of angina?
sub-endocardial ischaemia
Mechanisms in realtion to basic physiology of angina
Mismatch of blood supply to demand because of epicardial stenosis
Supply = coronary blood flow
demand = myocardial oxygen consumption
What was coronary flow reserve be able to accomodate?
myocardial O2 demand
What are the 2 regulatory systems that control coronary circulation?
- autoregulation (myogenic control)
- metabolic regulation
What are the determinants of myocardial oxygen consumption?
Varibale per unit mass of tissue:
- Tension development - LV pressure and volume
- Contractility
- HR
Fixed per unit mass of tissue = basal activity
Mass of tissue
tests of inducible ischaemia
- exercise stress test
- dobutamine stress echo
- myocardial perfusion imaging with either exercise or pharmacological stress
- cardia magnetic resoance imaging (cMR)
Anatomica assessment of coronary disease
- CT coronary angiography
- invasive angiography (more accurate)
Anatomic and functional assessment of coronary disease
- Invasive angiography and fractional flow reserve (FFR)
- cMR
- Novel CT
What are the aims of drug treatment of angina?
Reductaion in myocardial oxygen consumption
Reducation in the variability of coronary flow reserve
What techniques are used for revascularisation?
Percutaneous coronary intervention (stents and balloons)
Coronary artery bypass grafting (CABG)
What is the clinical presentation of an MI?
Chest pain - severe
Associated autonomic symptoms; nausea, sweating, terror
Breathlessness
Causes of myocardial infarction?
- Plaque rupture
- Plaque erosion
- Coronary embolism
- Coronary artery spasm/drugs
- coronary anaomaly
- spontaneous coronary dissection
Events modifying presentation of an MI
- Time of day
- inflammatory activity
- infection
- elevation of BP
- Catecholamines
Raised cardiomyocyte markers in the blood during an MI
- Troponin
- Creatine kinase MB isoform (CKMB)
- Creatine phosphokinase (CPK)
- AST
- Myoglobin
Immediate consequences of a STEMI
- Ventricular arrhytmia and death
- Acute left HF
Early complications of a STEMI
- Myocardial rupture
- Mitral valve insufficiency
- Ventricular septal defect
- Mural thrombosis and embolisation
Late complications of a STEMI
- LV dilation and heart failure
- Arrhythmia
- recurrent myocardial infarction
