Angina, ACS and arrythmias Flashcards

2
Q

Angina - definition

A
  • Myocardial ischaemia causes central chest tightness which may radiate to the jaw, teeth, neck or one or both arms.
  • Associated symptoms can include dyspnoea, nausea, sweatiness or fainting.
  • It is usually brought on by exertion, emotion, cold weather and heavy meals and is relieved by rest.
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3
Q

Angina - causes

A

Usually atheroma but rarely anaemia, aortic stenosis, tachyarrhythmias or hypertrophic CM.

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4
Q

Angina - 4 types

A
  • Stable angina – only induced by significant exercise and always relieved by rest.
  • Unstable or crescendo angina – increases in severity and occurs with minimal exertion or rest.
  • Decubitus angina – chest pain and dyspnoea that is precipitated by lying flat e.g. at night.
  • Variant or Prinzmetal’s angina – a rare form of angina that is caused by coronary artery spasm.
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5
Q

Angina - ECG changes

A
  • ECG – shows ST depression (ischaemia), flat or absent T waves or evidence of a previous MI.
  • If resting ECG normal consider exercise ECG, thallium scan, cardiac CT or coronary angiography.
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6
Q

Angina - conservative management

A
  • Modify risk factors – encourage to lose weight, exercise and stop smoking.
  • Ensure HTN and diabetes are well controlled.
  • If serum cholesterol >4 mmol/L - simvastatin 40mg OD at night.
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7
Q

Angina - medical management

A
  • Aspirin 75 mg OD – reduces cardiac mortality.
  • Atenolol 50-100mg OD – to reduce symptoms but has contraindications – respiratory diseasem LVF, bradycardia or Prinzmetal’s angina.
  • Isosorbide mononitrate 20-40 mg BD for prophylaxis or symptomatic relief with sublingual GTN.
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8
Q

Angina - additional medical management

A
  • Diltiazem or verapamil – calcium antagonists for patients with contraindications for β blockers.
  • Dihydropyridine – e.g. amlodipine - L-type calcium antagonists that can be added to β blocker.
  • Nicorandil 10-30mg BD – potassium receptor activator used for angina that is still not controlled.
  • Ivabradine – inhibits the pacemaker ‘funny’ current in the SA node and therefore reduces heart rate. It is useful in those that cannot take β blockers and has a similar efficacy.
  • Ranalozine – inhibits the late Na+ current and so prevents calcium overload and ischaemia.
  • Trimetazidine – inhibits fatty acid oxidation - myocardium uses glucose which is more efficient.
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9
Q

Angina - PTCA

A
  • Indications – poor response or intolerance to medical therapy, previous CABG or post thrombolysis with severe stenosis, symptoms or a positive stress test.
  • Complications – restenosis (30% in 6 months), emergency CABG (3%), MI (2%) or death (0.5%).
  • Stenting – NICE recommends PTCA is accompanied by stenting in 70% of patients. Combined therapy with aspirin and clopidogrel will reduce the risk of subsequent stent thrombosis.
  • IV Glycoprotein IIb/IIIa inhibitors – e.g. eptifibatide can reduce rate of procedure related ischaemic events by preventing platelet aggregation and thrombus formation.
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10
Q

Angina - CABG

A
  • Indications – to improve survival (left main stem disease or triple vessel disease) or to relieve symptoms (if unresponsive to drugs, unstable angina or if angioplasty unsuccessful).
  • Procedure – the heart is stopped and put onto cardiac bypass. The patient’s own saphenous vein or internal mammary artery (last longer) is used.
  • Prognosis – If angina persists or reoccurs restart anti-anginal drugs and consider angioplasty. It is known that >50% of grafts will close within 10 years but this can be prevented with low dose aspirin.
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11
Q

ACS - definition

A
  • Common pathology is rupture or erosion of a coronary artery plaque leading to thrombosis. The resulting syndrome depends on whether the coronary artery is totally, partially or transiently occluded:
  • STEMI - ST elevation and +++ troponin.
  • Non- STEMI - no ST elevation and + troponin.
  • Unstable Angina - ST depression or T wave inversion and no or trivial rise in troponin.
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12
Q

ACS - risk factors

A
  • Non-modifiable – increasing age, male gender and family history of ischaemic heart disease.
  • Modifiable – smoking, hypertension, diabetes, hyperlipidaemia, obesity or sedentary lifestyle.
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13
Q

ACS - diagnosis

A

Criteria include a rise and then fall in cardiac biomarkers e.g. troponin, symptoms of cardiac ischaemia, ECG changes, development of pathological Q waves and loss of myocardium on imaging.

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14
Q

ACS - symptoms and signs

A
  • Symptoms – central chest pain for >20 mins with nausea, sweatiness, dyspnoea and palpitations.

Can be silent in elderly and diabetics – syncope, pulmonary oedema, epigastric pain, vomiting, post-operative hypotension, oliguria, an acute confusional state, stroke or diabetic hyperglycaemia states.

  • Signs – distress, anxiety, pallor, sweatiness, increase or decrease in pulse and blood pressure, 4th heart sound, signs of heart failure, pansystolic murmur (papillary rupture or VSD) or a low grade fever.
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15
Q

ACS - investigations

A
  • ECG – hyperacute (tall) T waves, ST elevation and new onset left bundle branch block within hours of an infarction. Within days T wave inversion and pathological Q waves will develop.
  • CXR – to look for cardiomegaly, pulmonary oedema or a wide mediastinum in aortic rupture.
  • Bloods – measure FBC, Us and Es, glucose, lipids and serial levels of cardiac enzymes.
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16
Q

ACS - cardiac enzymes

A
  • Cardiac troponin - most sensitive and specific marker of myocardial necrosis. Levels rise within 3-12 hours from onset of chest pain, peak at 24-48 hours and return to baseline over 5-14 days (if normal after 6 hrs and ECG normal chance of missing MI is 0.3%).
  • Creatinine kinase – there are 3 isotopes (MM, BB and MB) – CK-MB levels rise within 3-12 hours of onset of chest pain, reach a peak at 24 hours and return to normal by 48-72 hours.
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17
Q

STEMI management

A
  • Give oxygen – 2-4L aiming for SaO2 of >95% (use caution in patients with COPD).
  • Give 300mg aspirin PO and 300mg clopidogrel OD (unless given by GP or paramedics).
  • Give analgesia – 5-10mg morphine IV with 10mg metoclopramide IV.
  • Give GTN – either 2 puffs or 1 tablet sublingually as required
  • Restore perfusionPCI is the choice within 12 hours. Where PCI is unavailable consider thrombolysis within
  • 5mg atenolol IV unless contraindication and 5mg lisinopril (where SBP >120mmHg) within 24 hours.
18
Q

ACS management

A
  • Give 2-4L of oxygen – aim for SaO2 of >95% (caution in COPD).
  • Give analgesia – 5-10mg IV morphine and 10mg IV metoclopramide.
  • Give nitrates – GTN spray or sublingual tablets as required
  • Give Low molecular weight heparin – 1mg/kg enoxaparin BD or fondaparinux (factor X inhibitor).
  • Give β-blockers – 50-100mg OD metoprolol tds (if contraindicated 60-120mg OD diltiazem tds).
  • Give IVI nitrates if pain continues – 50mg GTN in 50ml 0.9% saline at 2-10mL/hour.
  • Do an ECG and bloods – if ischaemia, raised troponin or diabetes patient is high risk – do angiography
19
Q

TIMI score and GRACE

A
  • Thrombolysis in myocardial infarction (TIMI) score – A – age >65 years, aspirin taken within 7 days or angina >2 times within 24 hours, B – biomarkers e.g. troponin are raised, C - CAD risk factors - >3 present, D – diagnosis of CAD and E – ECG changes - >0.5mm ST elevation.
  • GRACE (global registry of acute coronary events) risk score – this is recommended by NICE.
20
Q

MI or ACS - subsequent management

A
  • Bed rest for 48hrs – daily 12 lead ECG should be performed and heart, lungs and legs examined.
  • Address risk factors – stop smoking, encourage exercise, treat HTN, DM and hyperlipidaemia.
  • Aspirin – 75mg OD reduces the risk of vascular events e.g. MI and stroke by 29%.
  • Β-blockade – give 50-100mg metoprolol tds to decrease pulse to
  • ACE inhibitor – 2.5mg lisinopril OD should be given to all patients post MI.
  • Statin – even is cholesterol is normal give 40mg simvastatin OD to all patients post MI.
21
Q

Post MI complications

A

Cardiac arrest, cardiogenic shock, bradycardia or heart block, tachyarrhythmia’s, ventricular failure, pericarditis, DVT and PE, cardiac tamponade, mitral regurgitation, ventricular septal defect, Dressler’s syndrome or a left ventricular aneurysm.

22
Q

Arrhythmias - definition

A

A disturbance in heart rhythm - usually benign and intermittent but can lead to cardiac compromise.

23
Q

Arrhythmia’s - causes

A
  • Cardiac – myocardial infarction, coronary artery disease, left ventricular aneurysm, mitral valve disease, cardiomyopathy, pericarditis, myocarditis or abnormal conduction pathways.
  • Non-cardiac – caffeine, smoking, alcohol, pneumonia, drugs (β2 agonists, digoxin, L-dopa or tricyclics), metabolic disturbance (K, Ca, Mg, hypoxia or hypercapnia) or phaeochromocytoma.
24
Q

Arrhythmia’s - history

A

Ask about palpitations – onset and offset, nature (fast or slow and regular or irregular), duration and associated symptoms - chest pain, syncope, hypotension or pulmonary oedema.

25
Q

Arrhythmia’s - investigations

A
  • Bloods – FBC, Us and Es, glucose, Ca2+, Mg2+ and thyroid function.
  • ECG – look for signs of ischaemic heart disease, atrial fibrillation, short PR interval (in WPW), long QT (metabolic disturbance, congenital or drugs) or additional U waves (hypokalaemia).
  • 24 hour ECG monitoring – several recordings are needed as arrhythmia may be intermittent.
  • Echocardiography – to look for structural heart disease e.g. mitral stenosis or hypertrophic CM.
  • Provocation tests – exercise ECG, cardiac catheterisation or electrophysiological studies.
26
Q

Narrow complex tachycardia - definition

A

ECG shows a rate of >100 bpm and the QRS complex duration of <120ms (3 small squares).

27
Q

Narrow complex tachycardia - DD

A
  • Sinus tachycardia – normal P wave is followed by a normal QRS complex but rate is >100 bpm.
  • Supraventricular tachycardia – the P wave is absent or inverted after the QRS complex.
  • Atrial fibrillation – absent P waves and irregularly irregular QRS complexes are present.
  • Atrial flutter – the atrial rate is usually >300 bpm and the ECG has a ‘sawtooth’ appearance.
  • Multifocal atrial tachycardia – 3 or more P waves morphologies and irregular QRS complexes.
  • Junctional tachycardia – P waves are buried in QRS complexes or occur after them. These include AV re-entry tachycardia (e.g. WPW syndrome) and AV node re-entry tachycardia.
28
Q

Narrow complex tachycardia - management

A
  • Give O2 if SaO2 is <95%.
  • Continuous ECG monitoring – if it is irregularly irregular treat as AF if regular continue below.
  • If the patient is compromised use DC cardioversion – 100J, then 150J and then 200J.
  • Vagal manoeuvres – carotid sinus massage and the Valsalva manoeuvre.
  • Give 6mg adenosine bolus injection (repeat 6mg once and then give 12mg if required) (lower dose if patient on dipyridamole)
  • Monitor for adverse effects e.g. SBP <90 mmHg, heart failure, impaired consciousness or HR >200 bpm.
  • If adverse effects use DC cardioversion – 100J, then 150J and then 200J.
  • If no adverse effects use one of the following – 5-10mg IV verapamil over 2 mins, 40mg IV esmolol over 1 min followed by IVI, 500μg IV digoxin over 30 mins or 300mg IV amiodarone over 1 hour.
29
Q

Broad complex tachycardia - definition

A

The rate is >100bpm and duration of the QRS complexes is >0.12 secs (or >3 small squares).

30
Q

Broad complex tachycardia - DD

A

Most common cause is ventricular tachycardia (including torsade de pointes) but could also be supraventricular tachycardia with aberrant conduction e.g. AF or atrial flutter.

31
Q

Broad complex tachycardia - management

A
  • Oxygen – give high flow O2, connect to cardiac monitor and gain IV access.
  • Are there adverse signs – SBP <90mmHg, chest pain, heart failure or heart rate >150bpm.
  • If yes sedate the patient and perform DC cardioversion – 200J, 300J and finally 360J shock.
  • After shock or if no adverse signs – give 300mg Amiodarone IV in 20-60 mins then 900mg in 24 hours.
  • If the arrhythmia does not resolve and not yet done sedate the patient and perform DC cardioversion.
  • Correct hypokalaemia and hypomagnesaemia – with 60mmol KCl and 50% magnesium sulphate.
  • Consider maintenance anti-arrhythmic with sotolol if good LV function or amiodarone if not.
32
Q

Atrial fibrillation - definition

A
  • An irregular atrial rhythm at 300-600 bpm to which the AV node and ventricles responds intermittently.
  • When the ventricles are not primed reliably by the atria cardiac output falls by between 10 and 30%.
  • The main risk is embolic stroke – warfarin (INR range 2-3) reduces the risk from 4% to 1% per year.
33
Q

AF - causes

A

Caffeine, alcohol, post-operatively, hypertension, MI or cardiac ischaemia, heart failure, mitral valve disease, pulmonary embolism, pneumonia, hyperthyroidism, hypokalaemia, hypomagnesaemia.

34
Q

AF - clinical features

A
  • Symptoms – can be asymptomatic or can cause chest pain, palpitations, dyspnoea or syncope.
  • Signs – irregularly irregular pulse rate, variable intensity of the 1st heart sound and signs of LV failure.
35
Q

AF - investigations

A
  • ECG – will shows absent P waves and irregularly irregular QRS complexes.
  • Bloods – for Us and Es (K+ and Mg+), cardiac enzymes (e.g. troponin) and thyroid function tests.
  • Echo – to look for left atrial enlargement, mitral valve disease or poor left ventricular function.
36
Q

AF - acute management

A
  • If patient is haemodynamically unstable – give oxygen and IV sedation or GA and perform emergency cardioversion at 100J, then 150J and 300J. If DC cardioversion unavailable give IVI (5mg/kg over 1 hour) or PO (200mg tds) amiodarone or IV flecanide (2mg/kg) over 30 mins .
  • Control ventricular rate – 1st line treatment is a β-blocker e.g. metoprolol (50mg bd) or a CCB e.g. diltiazem (60mg tds) or verapamil (40mg tds). 2nd line is digoxin or amiodarone.
  • **Anticoagulation - **use LMWH until an assessment for emboli has been made. If patient is high risk (previous stroke, TIA or emboli) then warfarin should be started (INR target range is 2-3).
  • In addition to the above look for associated illness e.g. MI or pneumonia and treat accordingly.
37
Q

AF - chronic management

A
  • Rate control – 1st line treatment is a β-blocker e.g. metoprolol (50mg bd) or a CCB e.g. diltiazem (60mg tds) or verapamil (40mg tds). 2nd line is digoxin followed by amiodarone.
  • Anticoagulation – give warfarin (INR target range of 2-3) or 300mg aspirin OD if warfarin contraindicated or risk of emboli is very low. An alternative is dabigatron (direct thrombin inhibitor) – no need for monitoring or dose adjustment and less bleeding but expensive.
  • Rhythm control – if symptomatic, congestive cardiac failure, young patient or first presentation. Use DC cardioversion with 4 weeks pre-treatment with sotalol or amiodarone or medical cardioversion with flecanide (if no structural heart disease) or amiodarone.