1. ECGs and Acute Cardiac Events Workshop
Dr. Stewart McMorran
Consultant in Accident and Emergency
MB, BCh, MRCS, FFAEM

2. Objectives
Emergency management of common cardiac events
ST elevation MIs
Tachyarrhythmias
Bradyarrhythmias
Overview of management
Interactive case discussions

3. National Service Framework
NSF for coronary artery disease established 2000
Relevant to emergency medicine – need for timely reperfusion therapy
Door to needle time of 30 mins
Call to needle time of 60 mins
Results …
75% eligible patients thrombolysed within 30 minutes of hospital arrival

4. Impact of NSF Emphasis on timely delivery of reperfusion therapy
Thrombolysis – most places
Percutaneous Coronary Intervention:
Primary – limited availability
Rescue – local policy; if less than 50% resolution in ST segment elevation after 90 minutes
Coronary artery bypass graft

5. Impact on first line services
Timely assessment of chest pain in A&E
Extended skills of paramedics
Availability of Air Ambulances

7. ECG Lead Placement

8. Wall affected
Leads
Artery involved
Reciprocal changes
Anterior
V2-4
LAD
II, III, aVF
Anterolateral
I, aVL, V3-6
LAD, circumflex
Anteroseptal
V1-4
Inferior
RCA
I, aVL
Lateral
I, aVL, V5-6
circumflex
Posterior
V7-9
V1-3
Right ventricular
RV4-6

9. Criteria for thrombolysis
Chest pain, onset within last 12 hours plus any of:
ST elevation 2 mm or more in two contiguous chest leads
ST elevation 1 mm or more in two contiguous limb leads
Dominant R wave and ST depression in V1-3
New LBBB

14. Posterior MI Dominant R wave chest leads V1-3
ST depression chest leads V1-3
Turn ECG upside down and back to front – see typical changes of STEMI
Alternatively …
Posterior leads V7-9

17. Left Bundle Branch Block and MI
ST segment elevation more than 1 mm concordant (same direction) as QRS complex
ST segment depression more than 1 mm in V1,2,3
ST segment elevation more than 5 mm discordant (opposite direction) from QRS complex
Sgarbossa E et al. NEJM 1996 Feb 22:334(8) 481-7
check

19. Pericarditis
Widespread ST elevation (in leads looking at inflamed epicardium)
Reciprocal depression in aVR and V1
ST segment saddle shaped (concave upwards)
No Q waves

20. ST segment high take off
Normal variant
High take off or early repolarisation or J point elevation
Younger patients
Usually follows an S wave
T wave maintains independent wave form
No reciprocal ST segment depression
If in doubt, compare with earlier ECGs
J point = junctional point = where ST segment takes off from QRS complex

21. Arrhythmias - principles of treatment
Choice of intervention
- drugs vs. electricity
How symptomatic is patient
How urgent is need for action

22. Choice of intervention
Drugs:
Not always reliable
Side effects
Every anti-arrhythmic is potentially pro-arrhythmic
Electricity:
Reliable
Patient considerations
Environmental considerations

23. How symptomatic is patient
Signs of poor cardiac output
Heart rate
Too fast – depends on rhythm
Too slow – depends on patient
Systolic blood pressure < 90 mm Hg
Chest pain
Breathlessness
Altered level of consciousness

25. Synchronised DC Shock* Is QRS narrow (< 0.12 sec)?
Tachycardia
Algorithm
(with pulse)
Support ABCs: give oxygen; cannulate a vein
Monitor ECG, BP, SpO2
Record 12-lead if possible, if not record rhythm strip
Identify and treat reversible causes (e.g. electrolyte abnormalities)
Seek expert help
Synchronised DC Shock*
Up to 3 attempts
Normal sinus rhythm restored?
Probable re-entry PSVT:
Record 12-lead ECG in sinus rhythm
If recurs, give adenosine again & consider choice of anti-arrhythmic prophylaxis
If Ventricular Tachycardia
(or uncertain rhythm):
Amiodarone 300 mg IV
over min; then 900 mg
over 24 h
If previously confirmed SVT
with bundle branch block:
Give adenosine as for regular narrow complex tachycardia
Amiodarone 300 mg IV over min and repeat shock; followed by:
Amiodarone 900 mg over 24 h
Is patient stable?
Signs of instability include:
1. Reduced conscious level 2. Chest pain
3. Systolic BP < 90 mmHg 4. Heart failure
(Rate related symptoms uncommon at less than 150 beats min-1)
Is QRS narrow (< 0.12 sec)?
Broad
Narrow
Narrow QRS
Is rhythm regular?
Regular
Irregular
Broad QRS
Is QRS regular?
Use vagal manoeuvres
Adenosine 6 mg rapid IV bolus;
if unsuccessful give 12 mg;
if unsuccessful give further 12 mg.
Monitor ECG continuously
Irregular Narrow Complex Tachycardia
Probable atrial fibrillation
Control rate with:
-Blocker IV or digoxin IV
If onset < 48 h consider:
Amiodarone 300 mg IV min; then 900 mg over 24 h
Possibilities include:
AF with bundle branch block
treat as for narrow complex
Pre-excited AF
consider amiodarone
Polymorphic VT (e.g. torsade de pointes - give magnesium 2 g over 10 min)
Yes No
Possible atrial flutter
Control rate (e.g. -Blocker)
*Attempted electrical cardioversion is
always undertaken under sedation
or general anaesthesia
Stable
Unstable

26. Example 65 year old male Presents to A&E Palpitations /chest pain
MI 3 months ago
Sa02 95% on high flow oxygen
PR 190 BP 90/70

28. How do you know it is VT ?
May be difficult to distinguish ventricular tachycardia from atrial tachycardia with aberrant conduction e.g. LBBB
Default position – assume ventricular
Look for confirmatory features:
capture beats
fusion beats
concordance
extreme axis deviation

29. Main learning points VT is a malignant arrhythmia
DC cardioversion in presence of adverse signs
Check electrolytes especially K+ and Mg2+
Amiodarone anti-arrhythmic of choice

30. Example 25 year old female Presents to A&E Palpitations
Sa02 97% on high flow oxygen
PR 200 BP 110/70

32. Synchronised DC Shock* Is QRS narrow (< 0.12 sec)?
Tachycardia
Algorithm
(with pulse)
Support ABCs: give oxygen; cannulate a vein
Monitor ECG, BP, SpO2
Record 12-lead if possible, if not record rhythm strip
Identify and treat reversible causes (e.g. electrolyte abnormalities)
Seek expert help
Synchronised DC Shock*
Up to 3 attempts
Normal sinus rhythm restored?
Probable re-entry PSVT:
Record 12-lead ECG in sinus rhythm
If recurs, give adenosine again & consider choice of anti-arrhythmic prophylaxis
If Ventricular Tachycardia
(or uncertain rhythm):
Amiodarone 300 mg IV
over min; then 900 mg
over 24 h
If previously confirmed SVT
with bundle branch block:
Give adenosine as for regular narrow complex tachycardia
Amiodarone 300 mg IV over min and repeat shock; followed by:
Amiodarone 900 mg over 24 h
Is patient stable?
Signs of instability include:
1. Reduced conscious level 2. Chest pain
3. Systolic BP < 90 mmHg 4. Heart failure
(Rate related symptoms uncommon at less than 150 beats min-1)
Is QRS narrow (< 0.12 sec)?
Broad
Narrow
Narrow QRS
Is rhythm regular?
Regular
Irregular
Broad QRS
Is QRS regular?
Use vagal manoeuvres
Adenosine 6 mg rapid IV bolus;
if unsuccessful give 12 mg;
if unsuccessful give further 12 mg.
Monitor ECG continuously
Irregular Narrow Complex Tachycardia
Probable atrial fibrillation
Control rate with:
-Blocker IV or digoxin IV
If onset < 48 h consider:
Amiodarone 300 mg IV min; then 900 mg over 24 h
Possibilities include:
AF with bundle branch block
treat as for narrow complex
Pre-excited AF
consider amiodarone
Polymorphic VT (e.g. torsade de pointes - give magnesium 2 g over 10 min)
Yes No
Possible atrial flutter
Control rate (e.g. -Blocker)
*Attempted electrical cardioversion is
always undertaken under sedation
or general anaesthesia
Stable
Unstable

33. Main learning points
Supraventricular tachycardias are often well tolerated
Usually younger patients
Vagal manoeuvres may be successful
Adenosine is an effective anti-arrhythmic

34. Wolf Parkinson White

35. Wolf Parkinson White syndrome
Uncommon cause of SVT
Presence of accessory pathway (bundle of Kent)
Characteristic ECG features
Short PR interval (<120 ms)
Wide QRS (>120 ms)
Delta wave (slurred upstroke)
Unpredictable response to adenosine

36. Example 55 year old man Presents to A&E
1 hour history of central chest pain
Sa02 97% on high flow oxygen
PR 45 BP 80/50

38. Arrange transvenous pacing
BRADYCARDIA ALGORITHM (includes rates inappropriately slow for haemodynamic state)
Adverse signs?
Systolic BP < 90 mmHg
Heart rate < 40 beats min-1
Ventricular arrhythmias compromising BP
Heart failure
Atropine
500 mcg IV
Satisfactory
Response?
Risk of asystole?
Recent asystole
Möbitz II AV block
Complete heart block
with broad QRS
Ventricular pause > 3s
Interim measures:
Atropine 500 mcg IV
repeat to maximum of 3 mg
Adrenaline 2-10 mcg min-1
Alternative drugs OR
Transcutaneous pacing
Seek expert help
Arrange transvenous pacing
Yes No
Observe

39. Main learning points
Bradyarrhythmias may complicate inferior myocardial infarction (RCA supplies AVN)
Atropine may be effective
Pacing for symptomatic bradycardias resistant to atropine

40. Example 75 year old female Presents to A&E Palpitations
Sa02 95% on high flow oxygen
PR 175 irreg BP 80/50

42. Atrial fibrillation Treatment based on risk to patient from the arrhythmia
High risk
Rate > 150 beats min-1
Chest pain
Critical perfusion
Intermediate risk
Rate beats min-1
Breathlessness
Poor perfusion
Low risk
Rate < 100 beats min-1
Mild or no symptoms
Good perfusion

43. Main learning points Management of AF is complex
Universal agreement on high risk patients
Anticoagulation essential to prevent thromboembolic complications

44. Example 35 year old male Presents to A&E Palpitations
Sa02 97% on high flow oxygen
PR 200 BP 110/70

46. Any Questions?

47. Summary Chest pain is a common cause of attendance to hospital
Important to recognise STEMI
Arrhythmias may precede or complicate MI
Standardised treatment algorithms for initial management