MI & Management of Acute Coronary Syndrome Flashcards
What are the symptoms of myocardial infarction? [8]
- chest pain
- back pain
- jaw pain
- indigestion
- sweatiness, clamminess
- shortness of breath
- none (silent MI) - diabetes/dementia
- death
What are the signs of myocardial infarction? [8]
- Tachycardia (increased heart rate)
- Distressed patient/agitated
- Heart failure (crackles/raised JVP)
- Cardiogenic Shock - due severe ventricular damage
- Hypotensive
- Delirium
- Ventricular Arrhythmia - caused by acute MI
- None
What are the investigations used in acute myocardial infarction? [5]
- Electrocardiograph (ECG)
- Bloods - cardiac troponin
- CXR
- Echocardiogram
- Coronary angiogram
What are you looking for on ECG when investigating acute myocardial infarction? [1]
evidence of ST segment deviation
What are you looking for on CXR and echocardiogram when investigating acute myocardial infarction? [2]
evidence of acute heart failure and left ventricular systolic dysfunction
What is the role of a coronary angiogram when investigating acute MI? [1]
to look at the coronary artery anatomy for any narrowings that need intervention
What is troponin and what are the 3 types? [4]
protein that is an integral part of the cardiac myocyte
3 types:
- TnI
- TnT
- TnC
What is the significance of troponin in the bloodstream?
Presence in the bloodstream = a marker of cardiac necrosis
What is the universal definition of MI? [2]
Any elevation in troponin in clinical setting consistent with myocardial ischaemia
NOTE: isolated troponin elevation does not equal MI
Describe the 6 types of MI [6]
Type 1: Spontaneous MI due to a primary coronary event
- Coronary artery plaque rupture and formation of intraluminal thrombus
- Occludes the coronary artery leading to necrosis of that part of the heart that the artery supplies
Type 2: MI due increased oxygen demand and/or decreased oxygen supply to the heart muscle
- leading to the heart isn’t getting enough oxygen
Type 3: Sudden cardiac death
Type 4a: MI associated with percutaneous coronary intervention
Type 4b: MI stent thrombosis documented by angiography (stent reoccludes causing MI)
Type 5: MI associated with CABG (coronary artery bypass graft)
What conditions can cause Type 2 MI? [6]
- heart failure
- sepsis
- anaemia
- arrhythmias
- hypertension
- hypotension
What are the risk factors for atherosclerotic disease? [6]
- Hypercholesteremia
- Hypertension
- Diabetes mellitus
- Cigarette smoking
- Positive family history
- Obesity (BMI > 30)
What are the non-coronary causes of elevated troponin (type 2 MIs)?
- Congestive heart failure - acute
- Tachy-arrhythmias (i.e. tachycardia)
- Pulmonary embolism
- Sepsis
- Apical ballooning syndrome (Takotsubo cardiomyopathy)
- Anything that stresses the heart (e.g. critically unwell patient)
Define tachy-arrythmias (tachycardia) [1]
Abnormally high heart rate - puts the heart into an increased oxygen demand
Define pulmonary embolism [1]
Blockage of one of the pulmonary arteries in the lungs
What is sepsis and why can it cause elevated troponin? [2]
Life-threatening reaction to an infection
Heart is under a lot of pressure to fight infection
Define apical ballooning syndrome (Takotsubo cardiomyopathy) [1]
Temporary heart condition that is brought on by stress
Has the same symptoms as a heart attack but is not caused by any underlying cardiovascular disease
What are the causes of chronic elevation of troponin (that isn’t an MI)? [3]
Renal failure (troponin is cleared from the blood by the kidneys)
Chronic heart failure
Infiltrative cardiomyopathies (e.g. amyloidosis, hemochromatosis, sarcoidosis)
Define unstable angina [3]
An acute coronary event withOUT a rise in troponin (due to no myocardial necrosis)
i.e. Clinical presentation of an MI + ECG changes
or
Tight narrowing on coronary angiography
Define atherosclerosis [1]
a disease of the arteries in which fatty plaques develop on their inner walls, leading to eventual obstruction of blood flow
Describe the pathophysiology of atherosclerosis [6]
- Dysfunction of the endothelial lining of the vessel leads to inflammation of the vascular wall
- This causes the build up of lipids, cholesterol and inflammatory cells (i.e. cellular debris) within the intima and subintimal layers of the vessel wall
- This results in plaque formation and remodelling of the arterial wall
- At first the body tries to maintain adequate blood flow to the heart muscle by expanding the coronary artery eccentrically → i.e. compensatory expansion maintaining constant lumen
- But over time, the artery cannot expand anymore and the degree of the atherosclerotic plaque begins to impinge on the lumen
- this is when patients present with stable angina
- So under periods of increased demand of oxygen (e.g. exercise), the blood supply is not sufficient to maintain oxygen supply to the heart muscle and the patient presents with symptoms of ischaemia/angina
Define atheroma [1]
degeneration of the walls of the arteries caused by accumulated fatty deposits and scar tissue, and leading to restriction of the circulation and a risk of thrombosis
What are the risk factors to developing atheroma? [7]
- common in adults in Western countries
- high cholesterol
- smoking
- obesity
- lack of exercise
- diabetes
- hypertension
- family history of early atheroma
Name 1 clinical manifestation that can result from atheroma in…
- kidneys? [1]
- eyes? [1]
- brain? [1]
- heart? [1]
- legs? [1]
- chronic kidney disease (kidney failure)
- visual field defects
- stroke
- angina
- claudication
What are the 2 types of acute coronary syndromes and how do you get to a final diagnosis for each type? [6]
- ST elevation (STEMI)
- STEMI is always a myocardial infarction by definition
- Can either be:
- Qw MI → where there is full thickness infarction (or)
- NQMI → where there is partial thickness infarction
- No ST elevation (NSTEMI)
- Troponin release? NO → unstable angina
- Troponin release? YES → myocardial infarction
- Also can be either Qw MI or NQMI
What is the blood supply of the inferior part of the heart? [2]
right coronary artery (mostly)
left circumflex artery
What is the blood supply of the posterior part of the heart? [2]
circumflex artery (mostly)
right coronary artery
What is the blood supply of the lateral part of the heart? [1]
left circumflex artery
What is the blood supply of the anteroseptal part of the heart? [1]
left anterior descending artery
Label the coronary vessels in the image: [8]
- A: Aorta
- B: Left main coronary artery
- C: Left pulmonary artery
- D: Left circumflex
- E: Marginal artery
- F: Left anterior descending
- G: Right coronary artery
- H: Superior vena cava
Describe the evolution of acute ST elevation MI using the diagram [10]
- Graph A
- normal
- Graph B
- subtle elevation of J point
- subtle elevation of ST segment
- hyperacute tenting of T wave
- Graph C
- marked elevation of J point
- marked elevation of ST segment
- Graph D
- abnormal repolarisation of the ventricles → T wave inversion
- development of Q waves (due to full thickness infarction)
- Graph F
- months after MI, the ECG doesn’t ever go back to normal as you always get the Q waves
Describe the immediate management of STEMI [9]
- ABCD
- Put in an ambulance attached to defibrillator
- Aspirin 300mg PO
- Unfractionated heparin 5000U iv
- Morphine 5-10mg iv
- Anti-emetics
- Clopidogrel (in ambulance)
- 600mg if for PPCI (Primary Percutaneous Coronary Intervention)
- 300mg if for Thrombolysis (75mg if aged > 75)
- Ticagrelor 180mg (in hospital)
- Activate PPCI team (PPCI = primary percutaneous coronary intervention)
What is the subsequent management of STEMI? [5]
- Monitor in Coronary Care Unit for complications of MI*
- Give drugs for secondary prevention
- Echocardiogram for LV function and cardiac structure - given to all patients
- Cardiac rehabilitation
- If LVSD at >9 months consider primary prevention ICD
What drugs are given for secondary prevention of STEMI? [4]
ACE inhibitors (for all — if LVSD reduce mortality)
Beta Blockers (for all — if LVSD reduce mortality)
Statins —for all
Eplerenone (mineralocorticoid receptor antagonist) — only for diabetes and LVSD or clinical HF
What are the complications of STEMI? [5]
- Arrhythmias
- VT/VF —DC cardioversion
- AF — why (?heart failure/LVSD or other structural complication)
- Heart Failure
- Diuretics, inotropes, vasodilators
- Cardiogenic shock
- IABP (intra-aortic balloon pump, ventricular assist device)
- Myocardial rupture
- Septum —VSD - surgery
- Papillary muscle — mitral regurgitation - surgery
- Free wall — tamponade — usually fatal
- Psychological
- Anxiety/depression
- Cardiac rehabilitation essential for this
What drugs are given in the coronary care unit after a NSTEMI? [5]
Aspirin
Clopidogrel or ticagrelor
Low molecular weight heparin or fondaparinux
45 year old male smoker gives 1 hour history of central chest discomfort and vomiting. His ECG is as follows (see photo):
Is this…?
- Normal
- Anterior STEMI
- NSTEMI
- Lateral STEMI
- Inferior STEMI
- lateral STEMI
78 year old diabetic gives a several hour history of shoulder and left arm discomfort and sweating. Her ECG is as follows:
Is this…?
- NSTEMI
- Anterior STEMI
- Posterior STEMI
- Inferior STEMI
- posterior STEMI
22 year old student presents with a 3 day history of fatigue and flu-like symptoms and a several hour history of sharp left sided chest pain which is worse on inspiration. His ECG is as follows:
Is this…?
- Anterior STEMI
- Lateral STEMI
- Pericarditis
- Inferior STEMI
- pericarditis
A 56 year old woman complains of palpitations and dizziness. Her ECG is as follows:
Is this…?
- Anterior STEMI
- Posterior infarct
- No infarct
- Inferior STEMI
- no infarct
A 77 year old man with known LV systolic dysfunction who is visiting a friend in Glasgow and has forgotten to bring his “water tablets” wakes with acute breathlessness in the middle of the night. O2 sats are 83% and his ECG looks like this:
Is this…?
- Anterior STEMI
- Inferior STEMI
- LBBB
- Pericarditis
- LBBB
