24. ACS & AMI (acute coronary syndrome + acute myocardial infarction) Flashcards
What are the main presentations of coronary heart disease in community from most popular to least. (4)
- new exertional angina
- acute MI
- unstable angina
- sudden cardiac death
What is the difference between stable and unstable angina?
- Stable angina, chest pain will adhere to a specific pattern and symptoms usually disappear after a few minutes of rest (can be brought about my stress, alcohol, temperatures, overexertion, smoking etc)
- Unstable angina, symptoms are more unpredictable and serious and discomfort can last 20 minutes or more even during sleep or rest
When does stable angina occur?
If myocardial blood flow is reduced and when there is increased demand ischaemia
What are the symptoms in terms of chest pain in stable angina?
central chest tightness, often radiation to neck and/or arms
What is stable angina aggravated by? (stimulated/ brought about) (2)
by
- exertion
- stress
What brings about relied to stable angina? (2)
- stopping activity
- sublingual nitrate
Describe atherosclerosis steps in a progressive process that lead to stable angina. (4)
- normal
- fatty streak
- non-obstructive plaque (fibrous plaque)
- obstructive plaque; atherosclerotic plaque (>70% lumen) = stable angina
What is another name for acute coronary syndrome?
unstable angina
When does acute coronary syndrome (unstable angina) develop?
spontaneous plaque rupture and disruption and local thrombosis with degrees of occlusion
What 3 things can plaque rupture lead to?
- unstable angina
- NSTEMI
- STEMI
Which all ultimately lead to acute coronary syndrome (ACS)
What type of process is atherotrombosis?
an unpredictable process caused by unstable plaques
What are different types of ACS (acute coronary syndromes) caused by plaque rupture and thrombosis which lead to unstable angina? (4)
- unstable angina
- non ST elevation myocardial infarction (NSTEMI)
- ST elevation myocardial infarction (STEMI)
- sudden cardiac death
Why do plaques rupture?
- inflammation is important determinant in plaque stability along with other mechanisms including shear stress
- aggregated platelets build up on fibrin, fibrous cap and lipid rich core with macrophages
How to distinguish ACS symptoms (unstable angina) from stable angina?
ACS symptoms will almost always give symptoms AT REST compared to stable angina which is only on exertion
What factors are important o get from patient when making diagnosis about acute coronary syndromes? (unstable angina) (4)
- CHARACTER of patient’s pain to differentiate from other causes of pain; often tight band/ pressure/heaviness
- SITE of pain; watch for gestures; retrosternal
- RADIATON; neck and/or jaw, down arms
- AGGRAVATING; with exertion, stress, or relieving facotrs e.g. incomplete improvement with GTN or physical rest and/or ongoing
What are non-modifiable risk factors for coronary artery disease? (5)
- age
- gender
- creed/ faith
- family history+ genetic factors
- previous angina, cardiac events or interventions
What are modifiable risk factors for coronary artery disease? (5)
- smoking
- diabetes mellitus
- hyperlipidaemia
- hypertension
- lifestyle; diet and exercise
How does unstable angina present?
- Unstable angina pectoris (UAP) presents as angina on effort but also of progressive increasing frequency and severity often provoked by LESS exertion and/or then at rest
How does NSTEMI elevation MI present?
Will start with myocardiac ischaemic symptoms occurring at rest
What is seen on examination when diagnosing unstable angina and NSTEMI elevation MI? (4)
- patient may look unwell or fine
- often no specific features found
- check BP and heart rate
- listen for murmurs and crackles in chest
What is seen on ECG in unstable angina and NSTEMI?
May appear normal but can have:
commonly ST segment depression, transient/ short time ST segment elevation and/or T wave inversion
What do changes in ECG look like in
- unstable angina
- NSTEMI
- in unstable angina, changes occur AFTER pain
- in NSTEMI, changes persist (but not always)
What type of ECG is needed to detect delayed changes during an MI?
SERIAL ECG: two or more successive recordings from same patient made and compared to detect MI
Which groups of people have atypical ACS/unstable angina presentation? Why? (3)
- women
- elderly
- diabetics
Due to reduced pain sensation
What are common symptoms for acute coronary syndrome (ACS)? (3)
- breathlessness alone +/- signs of heart failure
- nausea and vomiting +/- other autonomic symptoms
- epigastric pain +/- recent onset indigestion
What are important cardiac biomarkers for diagnosing unstable angina and NSTEMI elevation MI (acute coronary syndromes)? (2)
cardiac troponin (cTn) I &T
What are cardiac biomarkers such as cardiac troponin, helpful in while diagnosing? (2)
- determining risk stratification
- elevated levels suggest high risk of adverse events
(helpful in diagnosis)
Are all troponin elevations ACS related and caused by atherothrombosis?
No
What is cardiac troponin (cTn)?
- part of contractile apparatus of myocytes’ thin filament
- normally undetectable
- elevated with compromise of myocyte integrity (when myocytes don’t communicate)
- sensitive and specific marker of cardiac myocyte damage
When is cardiac troponin elevated?
- during ischaemic damage
- when there is no compromise of myocyte integrity (when myocytes don’t communicate)
What is the immediate treatment for unstable angina and NSTEMI elevated MI? (acute coronary syndromes) step by step? (2)
- ABCDE approach
- MONA:
- morphine (or diamorphine)
- oxygen
- nitroglycerine (GTN spray or tablet)
- Aspirin 300mg orally (crush or chew)
What 2 things should ALL ACS patients receive when acute coronary syndrome symptoms appear as part of anti-platelet therapy?
They should receive BOTH;
- aspirin
- ADP receptor blocker, either:
1. Clopidogrel
2. Prasugrel
3. Ticagrelor
What is the dosage for Clopidogrel (ADP receptor blocker) for ACS patients?
Clopidogrel: bolus 200mg and 75mg daily
What is the dosage for Prasugrel (ADP receptor blocker) for ACS patients?
Prasugrel; Bolus 60mg and 10mg daily
What is the dosage for Ticagrelor (ADP receptor blocker) for ACS patients?
Ticagrelor: Bolus 180mg and 90mg BD daily
What is the treatment called that uses both aspirin and an ADP receptor blocker?
anti-platelet therapy
For how long is the dual anti-platelet therapy used for following an ACS event?
for one year following the ACS event
What are common anti-platelet agents used in drugs to prevent clotting? (8)
- terutroban
- sulotroban
- daltroban
- ifetroban
- ramatroban
- linotroban
- ridogrel
- terbogrel
(“troban” and “grel”)
What are common thrombin receptor antagonists which prevent clotting? (6) (anti-thrombotic therapy)
- ticlopidine
- clopidogrel
- prasugrel
- ticagrelor
- cangrelor
- elinogrel
What are 2 most common anti-thrombotic treatments for acute coronary syndromes e.g. unstbale angina or NSTEMI MI.
- intravenous unfractionated heparin (UFH)
2. low molecular weight heparin
What are the benefits of low molecular heparin? (4)
- improved clinical outcome
- easier to administer
- given subcutaneously and not needed to be monitored
- safe to give to pregnant women
What is low molecular heparin now largely replaced by?
even more specific anti-thrombotic Fondaparinux
What other medical therapies are used for acute coronary syndromes that don’t include anti-platelet or anti-trombotic therapies? (3)
- Beta blockers (in the absence of contrindications; asthma, acute left ventricular dysfunction, impaired AV nodal conduction), target heart rate should be between 50-60
- Statins (both acutely and chronically reduced further events)
- ACEIs; always in left ventricular dysfunction; controversial in normal function
What are ALL treatment options available for acute coronary syndromes? (5)
- Immediate treatment (ABCDE and MONA)
- anti-platelet therapy (both aspirin and ADP receptor blocker)
- anti-thrombotic therapy (intravenous unfractioned heparin or low molecular weight heparin)
- Medical therapy (e.g. Beta blockers, statins and ACEIs)
- coronary revascularisation
Which patients should be offered coronary revascularisation?
- high risk patients with unstable angina or NSTEMI MI who will benefit from early invasive strategy compared to medical therapy alone
What are common coronary revascularisation methods? (2)
- coronary angiography + revascularisation (PCI: percutaneous coronary intervention)
- CABG (coronary artery bypass graft) within 3 months since it’s highest risk period for recurrent events
Describe steps for heart catherisation. (7)
- needle introduced into brachial or femoral artery
- guide wire passed through needle across stenotic atherosclerotic plaque
- needle withdrawn and cathether introduced over wire which travels into aorta and l.side of heart through arteries
- double-lumen cathether with a balloon is slid over the guide wire, the balloon inflated to compress the plaque and open obstruction
- balloon cathether containing the stent is placed in the dilated area
- balloon is inflated and expanded, deploying the stnet
- once stent is deployed/put in place, the balloon and guide wire are removed
How long do patients stay in hospital for usually following an ACS event?
2-7 days (not all will have angiography and not all will have revascularisation)
Which group of people will have to be thoroughly examined for the right treatment path for more difficult decisions? (2)
- elderly
- people with co-morbidities
What are 3 main types of acute coronary syndromes?
- unstable angina
- NSTEMI MI (non-ST segment elevation)
- STEMI MI (ST segment elevation)
What occurs during a STEMI MI?
- plaque rupture leads to more complete or complete thrombotic occlusion of coronary lumen and infarction of distal myocardium
- proximal occlusion of main artery causes greater damage
- occlusion of a distal branch vessel can cause big problems
Occlusion in which part of the artery causes a greater damage?
in the proximal part of artery (proximal occlusion)