Acute coronary syndrome Flashcards
Most common clinical presentation of angina
Chest pain on exertion
Key factors contributing to progression of atheroma
Smoking Hypertension Hyperlipidemia Diabetes Obesity
Associated symptoms with angina
Dyspnea
Nausea
Diaphoresis
Faintness
Atheroma formation
- Damage to the arterial wall produces an inflammatory response and the development of atheromatous plaques.
- Exposure of the arterial endothelium to LDLs, the products of glycosylation associated with diabetes, vasoconstrictor hormones associated with hypertension, pro-inflammatory molecules from smoking, or excess adipose tissue results in the expression of adhesion molecules that allow leukocytes to stick to the arterial wall.
- Upon entry into the artery wall, blood monocytes begin to scavenge lipids and become foam cells.
- Macrophage foam cells release additional cytokines and effector molecules that stimulate smooth muscle cell migration from the arterial intima into the media, as well as smooth muscle cell proliferation.
- Initial fatty deposition of lipoprotein in the arterial intima develops into atherosclerotic plaques.
- Ischaemic symptoms may result from obstruction of blood flow due to atherosclerotic plaques or when a clot or vasospasm is superimposed on less severe plaques
At what occlusion % does angina typically occur
At >70% occlusion or coronary arteries
Precipitants of angina with fixed stenosis
mental and emotional stress, sexual activity, tachycardia from any cause, or the metabolic demands of fever, thyrotoxicosis, and hypoglycaemia
Types of angina
Stable: induced by activity, relieved by rest
Unstable: +frequency or severity, occurs on minimal exertion/at rest. ++Risk of MI
Prinzmetal: coronary artery spasm->at rest, STE that resolves once pain resolves
Risk factors for angina
Strong
advancing age smoking hypertension elevated LDL cholesterol isolated low HDL cholesterol diabetes inactivity obesity family history of premature ischaemic heart disease illicit drug use male sex
Investigations in angina
Resting ECG->normal
Hb
Fasting lipid profile
Fasting blood glucose
Others to consider: TSH->hypo(dyslipid, IHD)/hyper(+work load) HbA1C Stress ECG Angiography Stress echocardiograph
History and examination in angina
Angina pain syndrome description
Risk factors
Examination: associated cardiac, PAD, fundoscopy, bruits
Laboratory testing
Long term Management of stable angina
- Modify risk factors->beta blocker, statin, Anti-PLT, ACE-i
- Lifestyle->smoking cessation, exercise, diet
- Cardiac rehabilitation
- Consideration of revascularisation
- Management of acute symptoms
- Avoid precipitants
Pharmacological regime for angina risk modification
Aspirin 75-150mg OD
Metoprolol 25-100mg BD +/= Nifedipine (used if not controlled with b-blocker/verapamil) + Isosorbide mononitrate
Atorvastatin 80mg
Perindopril
Treatment of episodes of angina
Stop activity as soon as pain felt
Before taking medication lay down’GTN SL every 5 minutes. Max use 3 times
If persists >10minutes despite two doses, take a third and call the ambulance
Follow-up in angina
Assess risk factors, symptoms, complications, promote adherence to lifestyle/pharmacological
See every 4-6 months initially to help encourage smoking, weight, diet, activity
Patients not known to have diabetes mellitus should have a fasting blood glucose measurement every 3 years
Those with established diabetes mellitus should have HbA1c measured at least annually
A lipid profile should be obtained as clinically warranted to ascertain whether the goal of lowering LDL cholesterol by ≥50% is achieved and/or to check for compliance.
What is the single most important change people can make for cardiovascular health
Smoking cessation
Indications for referral in angina
Diagnostic uncertainty New angina of sudden onset Angina not controlled by drugs Refractory angina in those not suitable for CAG Previous CABG Positive stress test
Definition ACS
Unstable angina
NSTEMI
STEMI
Diagnosis of MI`
+ then -ve cardiac biomarkers +symptoms of ichemia or ECG changes of new ischemia or development of Q waves or loss of myocardium on imaging
Symptoms of ACS
Chest pain >20 mins
Sweaty, Nausea, dyspnea, palpitations
Signs of ACS
Distress, anxiety, pallor TachyC, bradyC 4th heart sound Evidence of heart failure Pansystolic murmur of papillary muscle, VSD Friction rub
Investigations in ACS
ECG Cardiac enzymes UEC Glucose Lipids CXR Coronary angiogram
Consider echo
Management of STEMI
- Do a 12 lead ECG->confirmed
- 02 2-4 L->aim for saturations >95%
- IV access->bloods for GBC, UECm glucose, lipids, cardiac enzymes
- Brief assessment:
- CVD history and risks
- Contraindications to fibrinolysis
- Examination; pulse, BP (both arms), JVP, murmurs, HF, limb pulses, scars from previous surgery - Aspirin 300mg chewed
- Clopidogrel 300mg (if followed by lysis) 600mg (if followed by PCI)
- Morphine 5-10mg IV + metoclopramide 10mg IV
- GTN SL 2 puffs/1 tables
- Primary PCI (need heparin) or thrombolysis
- Metoprolol + statin + ACEi
- CXR
- DVT prophylaxis
- Wean off GTN when stabilised
- Stop heparin when pain free for 24 hours (give at least 3-5 days)
- Serial ECGs, troponins >12 h after pain
- Address modifiable risk factors
- Gentle mobilisation
- Notify/arrange f/u with GP
Ways to restore blood flow
PCI
Fibrinolysis
When should PCI be performed within
performed within:
60 minutes for patients presenting within the first hour of symptom onset
90 minutes for patients presenting between 1 and 3 hours after symptom onset
90 to 120 minutes for patients presenting between 3 and 12 hours.
If targets for PCI cannot be achieved in STEMI
Fibrinolysis given within 30 mins of arriving at hospital
Consideration for reperfusion therapy
Patients should be considered for reperfusion therapy only if all of the following are present:
- Ischaemic/infarction symptoms of longer than 20 minutes. This would include not only chest pain but also other symptoms of myocardial infarction such as chest discomfort or pressure, shortness of breath, pulmonary oedema, sweating, dizziness and light-headedness
symptoms commenced within 12 hours - ST elevation or presumed new left bundle branch block on ECG
- No contraindications to reperfusion therapy.
Indications for fibrinolysis
prolonged ischaemic chest pain that has begun within the previous 12 hours, in the presence of significant ST segment elevation or left bundle branch block that is presumed new
Absolute contraindications for thrombolysis
Risk of bleeding
- active bleeding or bleeding diathesis (excluding menses)
- significant closed head or facial trauma within 3 months
- suspected aortic dissection (including new neurological symptoms)
Risk of intracranial haemorrhage
- any prior intracranial haemorrhage
- ischaemic stroke within 3 months
- known structural cerebral vascular lesion (eg –arteriovenous malformation)
- known malignant intracranial neoplasm (primary or metastatic)
Relative contraindications for thrombolysis
Risk of bleeding
-current use of anticoagulants: the higher the international normalised ratio (INR), the higher the risk of bleeding
non-compressible vascular punctures
-recent major surgery (within 3 weeks)
-traumatic or prolonged (more than 10 minutes) cardiopulmonary resuscitation
-recent (within 4 weeks) internal bleeding (eg gastrointestinal or urinary tract haemorrhage)
active peptic ulcer
Risk of intracranial haemorrhage
-history of chronic, severe, poorly controlled hypertension
severe uncontrolled hypertension on presentation (more than 180 mm Hg systolic or more than 110 mm Hg diastolic)
-ischaemic stroke more than 3 months ago, dementia, or known intracranial abnormality not covered in absolute contraindications
Other
pregnancy
Fibrinolysis regime
Alteplase + heparin
When should long term anticoagulation therapy be considered following MI
When large
Akinetic/dyskinetic area
Left mural thrombus on echo
Enoxaparin + warfarin
ECG criteria for thrombolysis
STE >1mm in 2 + limb leads or >2mm in 2 or more chest leads
LBBB of new origin
Posterior changes
High risk features in NSTEMI
Presentation with clinical features consistent with acute coronary syndrome (ACS) and any of the following high-risk features:
- repetitive or prolonged (more than 10 minutes) ongoing chest pain or discomfort
- elevated level of at least one cardiac biomarker (troponin or creatine kinase-MB isoenzyme)
- persistent or dynamic electrocardiographic changes of ST-segment depression 0.5 mm or more, or new T-wave inversion 2 mm or more
- transient ST-segment elevation (0.5 mm or more) in more than two contiguous leads
- haemodynamic compromise—systolic blood pressure less than 90 mm Hg, cool peripheries, diaphoresis, heart failure, and/or new-onset mitral regurgitation
- sustained ventricular tachycardia
- syncope
- left ventricular systolic dysfunction (left ventricular ejection fraction less than 0.40)
- prior percutaneous coronary intervention within 6 months or prior coronary artery bypass surgery
- presence of known diabetes (with typical symptoms of ACS)
- chronic kidney disease (estimated glomerular filtration rate less than 60 mL/minute) (with typical symptoms of ACS)
Intermediate risk features
Presentation with clinical features consistent with ACS and any of the following intermediate-risk features AND NOT meeting the criteria for high-risk ACS:
1. chest pain or discomfort within the past 48 hours that occurred at rest, or was repetitive or prolonged (but currently resolved)
2. age more than 65 years
3. known coronary heart disease—prior myocardial infarction with left ventricular ejection fraction 0.40 or more, or known coronary lesion more than 50% stenosed
no high-risk changes on electrocardiography (see high-risk features above)
5. two or more of the following risk factors: known hypertension, family history, active smoking or hyperlipidaemia
6. presence of known diabetes (with atypical symptoms of ACS)
7. chronic kidney disease (estimated glomerular filtration rate less than 60 mL/min) (with atypical symptoms of ACS)
prior aspirin use
Acute management of NSTEMI
Initial assessment->ECG 02 2-4 L aim >94% IV access->bloods Analgesia + antiemetic GTN spray
High risk:
Aspirin 100-150mg
Clopidogrel 75mg following initial loading 600mg
Enoxaparin
Metoprolol/verapamil/diltiazem, statin, ACEi
High risk, abnormal ECG or +ve troponins:Tirofiban
- ->Angiogram planned: bivalirudin
- ->No angiogram: fondaparinux
In intermediate->monitor and reassess (inc cardiac biomarkers)
Low risk->cardiac assessment to rule of CAD->stress testing
Consderations post-thrombolysis
Hypotension
Allergic reaction
Reduced GCS
Bleeding
Complications post-MI
Hypotension Pulmonary edema RVF Arrythmias VSD, papillary muscle perforation Thrombus Pericarditis
Patient instructions
D/C after 5-7 days if uncomplicated
May return to work after 2 months->if heavy labour, need lighter work
Diet high in oily fish, fruits, vegetables, fibre. Low saturated fats
Exercise regularly, lose weight
Intercourse best avoided for a month
Avoid air travel for 2 months
R/V 5 weeks post MI->symptoms
R/V at 3 months->check lipids, glucose, BP etc
A timeline of common post-MI complications
First day: Heart failure.
2–4 days: Arrhythmia, pericarditis.
5–10 days: Left ventricular wall rupture (acute pericardial tamponade causing electrical alternans, pulseless electrical activity), papillary muscle rupture (severe mitral regurgitation).
Weeks to months: Ventricular aneurysm (CHF, arrhythmia, persistent ST-segment elevation, mitral regurgitation, thrombus formation).
Indications for CABG
Unable to perform PCI
Left main CAD
Triple vessel disease
Depressed ventricular function