acute coronary syndromes Flashcards Preview

BDS2 - BAMS > acute coronary syndromes > Flashcards

Flashcards in acute coronary syndromes Deck (83)
Loading flashcards...

what are the 2 processes in which acute coronary syndromes can occur

- blood vessel narrowing
- blood vessel occlusion


what is blood vessel narrowing

- vessel narrowed due to an atheroma forming in the vessel blocking part of it


what is the consequence of blood vessel narrowing

- small narrowing can have a large effect
- inadequate O2 delivery for tissue needs, causing cramp in the affected muscle/tissue


what can happen when you have narrowing of blood vessels

- can get a pain in your chest (angina) when you exercise beyond the ability for O2 to get round body
- it is completely reversible at first but over time it will lead to damage to the heart (hypoxia) due to lactic acid build up


what is blood vessel occlusion

- no delivery of O2 to tissue
- have atherosclerotic lesion which causes a change to the endothelial wall of blood vessel causing them to open to the blood flow which platelets then stick to ad eventually block the flow or break off and become lodged elsewhere


what can happen due to blood vessel occlusion

- tissue death
- instead of hypoxia you get cell death as their is no O2


what is more severe; blood vessel occlusion or narrowing

- occlusion
- has more severe pain due to death of tissue/muscle
- get loss of function of that tissue


what is the reversible side of ischaemia

angina and peripheral vascular disease


what is a myocardial infarction

tissue death as a consequence of blockage of arteries


what can be different about the diagnosis of acute coronary syndromes

different patients feel different things
- need their medical history


what are the 2 ECG findings for ACS

- STEMI = ST segment elevation myocardial infarction
- NSTEMI= non-ST segment elevation myocardial infarction


what are the biomarkers of myocardial infarction

- troponin mainly


what is atherosclerosis

- gradual build up of plaque in blood vessels which eventually cause the vessel to become blocked or the atherosclerotic lesion can break off and become lodges elsewhere in the body


what can atherosclerosis lead to

- unstable angina
- acute myocardial infarction
- death from coronary disease


where do coronary arteries sit

they come away from the aorta behind where the artic valve opens


what can sometimes happen in an increased HR

can miss the coronary artery as there is less time for the blood to flow through


what can happen in coronary artery disease in relation to atherosclerosis

- can make blood vessels narrower
- makes heart function harder than it should be


what is angina pectoris

reversible ischaemia of one or more coronary arteries
- narrowing of one or more coronary arteries


where is angina pectoris

angina in the chest


what makes 'classical' angina worse

- chest pain that feels like a heart attack but will stop at rest


what is 'unstable' angina

- symptoms at rest with no biomarkers
- angina pain with no exercise
- can have loose flap of atherosclerotic tissue that flaps down then up, narrowing the vessel
- don't have permanent muscle damage but presents like a MI


what are the symptoms of angina

- described as a 'central crushing pain'
- radiation to the arm, back or jaw possible
- pain is blood vessel pain = autonomic NS in heart, mainly on the left side as left forms the aorta etc and embryologically formed the same


what are some 'classical' angina symptoms

- no pain at rest
- pain with certain level of exercise = pain felt once used up all O2 around the heart
- pain relieved by rest
- patient lives within limits of tolerance = they will learn what they are able to do
- gradual deterioration as progresses = will only be able to do less and less exercise before resting


what are some 'classical' angina signs

- often none
- occasionally hyper dynamic circulation = anaemia, hyperthyroidism, hypovolaemia


what are investigations for angina

- ECG = at both rest and exercise, shows area of myocardial ischaemia, angina will cause ST segment depression
- need to eliminate other possible diseases
- angiography
- echocardiography
- isotope studies (function assessment)


what does a coronary artery blockage do

restrict blood flow


what are some angina treatment

- reduce O2 demands of the heart
- increasing O2 delivery to tissues


how can you reduce O2 demand to the hear

- reduce after load (blood pressure)
- reduce preload (venous pressure)


how can you increase O2 demand to the tissues

- dilate blocked/narrowed vessels = angioplasty, stretches bv's
- bypass blocked/narrowed vessels = CABG


what is CABG

- coronary artery bypass grafting
- add extra bv to avoid damaged one
- it is a one off operation as there is a risk of the heart not starting again