Acute coronary syndromes: presentation, management and treatment Flashcards
what is the 2nd most common cause of death in Scotland?
Heart disease
What is an Acute Coronary Syndrome?
Any sudden event suspected or proven to be related to a problem with the coronary arteries. ie Spontaneous plaque rupture & local thrombosis, with degrees of occlusion Problems arise due to myocardial ischaemia (reduction in the blood supply to the heart muscle) ie unstable angina, NSTEMI and STEMI
what is cardiac arrest? (4)
Abnormal heart rhythm not compatible with life - Ventricular fibrillation or tachycardia - Asystole Can occur during the acute phase of an MI Can occur late after an MI Can be unrelated to an MI
example of a chronic ischaemic heart disease
stable angina
examples of acute coronary syndromes? (2)
unstable angina myocardial infarction - STEMI (full thickness damage of heart muscle - transmural, more serious) or Non STEMI (subendocardial - partial thickness)
complete coronary occlusion causes what changes on an ECG initially and at 3 days?
ST elevation Q waves
partial coronary occlusion causes what changes on an ECG initially and at 3 days?
no ST elevation no Q waves
what is a transmural MI
a myocardial infarction that involves the full thickness of the myocardium STEMI
diagnosis of myocardial infarction
Detection of cardiac cell death/injury: +ve cardiac biomarkers AND one of: - symptoms of ischaemia - new ECG changes - evidence of coronary problem on coronary angiogram or autopsy - evidence of new cardiac damage on another test
what are cardiac biomarkers
Cardiac biomarkers are substances that are released into the blood when the heart is damaged or stressed. Measurements of these biomarkers are used to help diagnose acute coronary syndrome (ACS) and cardiac ischemia, conditions associated with insufficient blood flow to the heart.
Name some cardiac biomarkers
cardiac troponin - 2 types, 1 in STEMI 1 in NSTEMI myoglobin CK-MB
non-coronary causes of a troponin rise? (6)
Pulmonary embolism Cardiac contusion Anaemia Sepsis Renal failure Sub-arachnoid haemorrhage - burst blood vessel in the brain
types of MI
Type 1,2,3,4a,4b and 5 1 - spontaneous MI 2- imbalance of O2 supply/demand 3- sudden cardiac death 4a- MI associated with percutaneous coronary intervention 4b- associated with verified stent thrombosis via angiography or autopsy 5- MI associated with CABG
spontaneous MI can be due to what types of things?
atherosclerosis (but not always) Coronary vasospasm - cocaine, triptans (anti-migraine medication), 5-FU (chemotherapy) Coronary dissection - often younger, healthy females Embolism of material down coronary artery - thrombus or a tumour Inflammation of coronary arteries (vasculitis) Previous radiotherapy to chest causing fibrosis and stenosis of coronary arteries
MI typical history
Chest pain - may radiate to neck/arm - often they deny it is a “pain”, more a “discomfort” - Severe, but not “agony” - May be associated with nausea, sweating, breathlessness
cardiac risk factors (8)
Male Age Known heart disease Known high blood pressure High cholesterol Diabetes Smoker Family history of premature heart disease
Examination for ACS
May look very unwell or completely fine Often no specific features to find Ensure that you check: HR, BP Listen for murmurs, crackles in chest
key investigations for ACS
ECG bloods FBC - U&E, Glucose, lipids, cardiac enzymes CXR - cardiomegaly ECHO - regional wall abnormalities
what are hyperacute T waves
seen in transmural ischaemia (complete occlusion) are broad-based and symmetrical (normally asymmetric- sharper decline) usually with increased amplitude often associated with a depressed ST take off Almost always seen in conjunction with ST segment elevation
what are the T waves like in partial coronary occlusion
T wave inversion or may be normal ST depression
Problems in L anterior descending coronary artery causes what type of MI?
anterior MI
Problems in circumflex coronary artery causes what type of MI?
lateral MI - easily missed as may be little ECG change
posterior MI
easily missed because no ECG leads on chest usually the posterior wall is supplied b ythe RCA - see some inferior ST elevation left circumflex may supply posterior wall - may not see any ST elevation
posterior ECG leads
posterior myocardium is not directly visualised by the standard 12-lead ECG take the 6 anterior leads off and replace with V7, V8, V9
inferior ST depression on ECG (dip in ST) could be caused by what?
NSTEMI or unstable angina
reperfusion therapy options (2)
mechanical - in cath lab - PCI (Angioplasty, also called percutaneous coronary intervention) pharmacological
thrombolysis bolus is called
tenecteplase
risks of thrombolysis (3)
used in more severe cases - if you can’t get to a cath lab Bleeding Don’t give if recent stroke, ever had a previous intracranial bleed Caution if recent surgery, on warfarin, severe hypertension
if you’re having a STEMI and can get to a cath lab in 2 hours then what should you do?
transfer to cath lab for primary PCI
if you’re having a STEMI and can’t get to a cath lab in 2 hours then what should you do?
Thrombolysis and then transfer
Describe typical patient with NSTEMI
Compared to STEMI, patients tend to be: older more likely to have previous MI/CABG/PCI more likely to have other medical problems May not be such a clear, obvious “coronary” presentation Could be type 2 MI (imbalance of O2 s+d) in a 85 year old with anaemia and pneumonia
troponin will NOT be elevated in which condition
unstable angina
describe unstable angina
Convincing anginal symptoms Rapidly worsening (crescendo history) Occurring at rest ECG may be normal or abnormal NO cell death so troponins will NOT be raised
general management of suspected ACS
Admit to hospital Cardiac monitor Give O2 only if levels low
Investigations carried out for ACS (2)
ECGs Repeat if not sure about changes Consider doing posterior leads Blood tests Check troponin Now can do immediate “Point of Care” test Also check Hb, kidney function, cholesterol
Treatment for ACS:
To manage chest pain:
- Glycerol trinitrate (GTN) - Vasodilator - opens up coronary arteries - Can give sub-lingual or as intravenous infusion - no releif if STEMI
- Opiates (eg morphine) - Helps relieve anxiety. Also venodilator
Optimise cardioprotective treatments:
- Antiplatelets - aspirin, clopidogrel
- Anticoagulate
- B blockers - reduce myocardial O2 demand
- ACE inhibitors
- High-dose statin - lower cholesterol
Revascularisation:
- STEMI and high risk NSTEMI - angioplasty
- If multi vessel damage - CABG instead
anti-thrombotic drug options
anti platelet (usually dual):- Aspirin and an ADP receptor blocker: clopidogrel ticagrelor check that they’ve not been sick anti-coagulant:- subcutaneous heparin LMWH - Low-molecular-weight heparin Fondaparinux
other drugs used to treat ACS
beta blockers - reduce work the heart has to do statin - cholesterol lowering drugs ACE inhibitors - help heart muscle recover
coronary angiography after NSTEMI
Ideally do angio within 48 hours Can use a risk calculator to assess whether should have angio
coronary artery bypass is used for which heart diseases
Three vessel disease Left main stem disease Disease not amenable to PCI
management of ACS in hospital
Now often home within 3-4 days Keep attached to monitor for first 24-48 hours Get an echo - shows size of wall motion abnormality and whether hypokinetic or akinetic; overall contractility, degree of mitral regurgitation. Presence of mural thrombus - form in the heart or aorta. Also ocheck for LV function Listen for murmurs and signs of heart failure every day
mechanical complications with following an MI
rupture of infarcted myocardium Acute Ventricular Septal Defect Mitral valve dysfunction due to papillary muscle rupture
how can a stent cause thrombosis
Takes a period of time for a stent to become endotheliesed ie “embedded” into coronary artery wall During that time, the blood is exposed to the metal stent and could thrombose, blocking off the stent unless on anti-platelet drugs Need anything from 1 month to 12 months of dual anti-platelet therapy (DAPT) Premature discontinuation of DAPT may be fatal
ST elevation suggests what
a blocked coronary artery and ongoing myocardial cell death need to open a coronary artery ASAP
how do ACS symptoms contrast with stable angina?
ACS symptoms will almost always be at rest SA are only on exertion
history of stable angina vs NSTEMI
Unstable Angina-angina on effort, but of progressive, increasing frequency and severity, often provoked by less exertion and/or then at rest. NSTEMI will much more often start with myocardial ischaemic symptoms occurring at rest.
atypical ACS presentation is found often in whom?
women the elderly diabetics
immediate treatment of unstable angina and NSTEMI
ABCDE approach then MONA morphine O2 nitroglycerin (GTN) aspirin
Angiotensin converting enzyme inhibitors used if what is present?
L ventricular dysfunction
options for opening infarct related artery?
primary PCI (better) fibrinolysis
when is fibrinolytic therapy opted for
treatment of choice when PCI cannot be performed Pre-hospital fibrinolysis significantly reduces ‘call for help-to-needle’ compared with in-hospital administration
fibrinolytic therapy and clear increased risk of bleeding & intra-cranial haemorrhage in some patients:
Age > 75 Female sex Previous stroke Low body weight (F<65 kg, M<70 kg) SBP > 160 mmHg INR > 4 Chronic kidney disease & elevated creatinine
ACS secondary prevention
General measures: stop smoking, diet, exercise etc Co-morbidities: control BP, glycaemic control etc. Aspirin and clopidogrel (for one year only) beta-blockers (to heart rate <60bpm) Statins (to LDL-c <3.2mmol/l, Total-c 5 mmol/l) Angiotensin converting enzyme inhibitors (always if left ventricular dysfunction, probably if “normal” function) ramipril 5mg BiD or equivalent.
sudden cardiac death often caused by what?
VT or VF As an ACS, the atherothrombotic event causes acute myocardial ischaemia and subsequent sufficient electrical disturbance to cause ventricular arrhythmia. Not all SCDs or aborted SCDs are ACS events.
ventricular fibrillation
Defibrillation the only effective treatment for VF arrest. VF tends to rapidly deteriorate into asystole. Asystole more difficult to restore CO Rapid & effective team work in resuscitation efforts is essential to give optimal chance of success.
2 main groups of immediately life threatening complications of acute MI?
Mechanical complications Ventricular arrhythmic complications both need urgent intervention
free wall rupture
type of mechanical complication Occurs at the edge of the infarcted area. Leads to haemopericardium and acute tamponade
ECG signs of VF
P-waves and QRS complexes are not present Heart rhythm is highly irregular The heart rate is not defined (without QRS complexes)
STEMI: Signs, symptoms, diagnosis/investigation, management
Signs:
- No GTN relief
- Distress/anxiety
- tachycardia
- HF
Symptoms:
- Severe chest pain >20 mins, left arm, neck or jaw
- SOB
- Fatigue
- pre-syncope
- syncope
- nausea/sweating
- palpitations
diagnosis/investigation:
- ECG - tall T waves, ST elevation
- CXR - cardiomegaly, pulmonary oedema
- FBC
- Cardiac biomarkers - raised troponin levels
management: - Emergency!
- PCI or thrombolysis if they can’t get that
- Aspirin and clopidogrel, Morphine, O2
- Beta blockers
- Consider CABG
- opiates
NSTEMI: Signs, symptoms, diagnosis/investigation, management
Signs:
- ECG - no ST elevation
Symptoms:
- Severe chest pain >20 mins, left arm, neck or jaw
- SOB
- Fatigue
- pre-syncope
- syncope
- nausea/sweating
- palpitations
diagnosis/investigation:
- ECG - repeated
- CXR - cardiomegaly, pulmonary oedema
- FBC
- Cardiac biomarkers - raised troponin levels
- GTN trial
management:
- Aspirin and clopidogrel
- Beta blockers/ CCB
- GTN
- ACEI if hypertensive
- LMW heparin
- Coronary angiography
Unstable angina: Risk factors. signs, symptoms, diagnosis/investigation, management
Risk factors:
- Female
- CAD
- Smoking
- Age
- Diabetes
- Hypertension
Signs:
- ECG - ST depression or normal
- 4th heart sound
- Carotid bruits - murmur due to stenosis
Symptoms:
- Chest pain - increased freq, severity and duration
- Pain radiating to jaw/arm
- SOB
Diagnosis/investigation:
- ECG
- Cardiac biomarkers - Troponin
- CXR/CT/MRI
Management:
- Aspirin/clopidogrel
- Statin
- B blocker
- ACEI
- cardiac rehab
