Syncope and the ECG

1. Dan Pixley 2018

4.  common; about 3–5% of ED visits and 1–6% of
hospital admission
 underlying cause: unknown (34-36%),
vasovagal (18-21%), and cardiac (9.5-18%)
 4 Diagnostic categories:
◦ Reflex-mediated
◦ Orthostatic
◦ Cardiac
◦ Cerebrovascular

5.  is a rule for evaluating the risk of adverse
outcomes in patients presenting with syncope
 CHESS
◦ Congestive heart failure
◦ Hematocrit < 30%
◦ Abnormal ECG
◦ Shortness of breath
◦ Triage systolic blood pressure < 90
 96% sensitive and 62% specific
 99.2% negative PV, 24.8% PPV

6.  Can Quick BRAD Walk Home
◦ Conduction blocks
◦ Long/ short QT
◦ Brugada
◦ RV infarction/ coronary ischaemia
◦ ARVD
◦ DCM
◦ WPW
◦ Hypertrophy (HCM or LVH due to AS)

7.  Age
 History of arrhythmias, IHD, structural Heart disease
 Diabetes
 newly abnormal ECG
 Elevated troponin level
 History of Cardiac disease
 Patients with pacemakers or other cardiac devices:
◦ have a high index of suspicion in these patients for
arrhythmia and / or cardiac device malfunction
◦ All patients with pacemakers with unexplained collapse
must be admitted until such time as their pacemaker can be
checked
◦ Most devices can be interrogated for a record of significant
arrhythmia over an extended period of weeks

8.  65 year old male with history of
hypercholesterolaemia, HTN and T2DM
presents with epigastric pain.
What do we do?

9.  74 year old male with history of COPD, HTN
and IHD presents with sharp/central chest
pain of 30 mins duration and then a short
syncope. HR 72, BP 105/62,sats 95% RA
What do we do?
Image from ref 2

10.  40-50% of all myocardial infarctions
 Up to 40% of patients with an inferior STEMI will
have a concomitant right ventricular infarction
◦ can develop severe hypotension in response to nitrates and generally have
◦ develop significant bradycardia due to second-or third-degree AV block
 RV infarction suggested by
- ST elevation in lead III > lead II
- Presence of reciprocal ST depression in lead I
- Signs of right ventricular infarction: STE in V1 and V4R

11.  48 year old female with a history of IHD
presents with left sided chest pain radiating
to jaw. Not relieved by normal GTN
What do we do?
Image from ref 1

12.  Widespread horizontal ST depression, most
prominent in leads I, II and V4-6
 ST elevation in aVR ≥ 1mm
Requires Urgent referral to Cardiology for PCI

13.  65 year old male with history of T2DM and
smoking self presents after an episode of
chest pain + syncope. The chest pain
resolved 30 mins prior to arrival in ED

14.  pattern of deeply inverted or biphasic T waves in
V2-3,
 specific for a critical stenosis of the left anterior
descending artery (LAD)
 Patient may be pain free by the time ECG is taken
but they are at extremely high risk for extensive
anterior wall MI within the next few days to
weeks.
 Require PCI

16.  35 year old male with nil medical history
presents after his bucks party with
palpitations.

17.  most common sustained arrhythmia
 Lifetime risk over the age of 40 years is ~25%
 Ischaemic heart disease
 Hypertension
 Valvular heart disease (esp. mitral stenosis / regurgitation)
 Acute infections
 Electrolyte disturbance (hypokalaemia, hypomagnesaemia)
 Thyrotoxicosis
 Drugs (e.g. sympathomimetics)
 Pulmonary embolus
 Pericardial disease
 Acid-base disturbance
 Pre-excitation syndromes
 Cardiomyopathies: dilated, hypertrophic.
 Phaeochromocytoma
Reference 2

18.  47 year old accountant presents SOB pus
presyncopal

19.  The atria contract at 300 beats per minute
causing a ‘seesaw’ baseline. Beats are
transmitted with a 2:1, 3:1 or 4:1 block,
leading to ventricular rates of 150, 100 and
75 BPM respectively.
 Vagal manouvers +/- Adenosine. A flutter
will not usually respond to this. This will
often give a transient period of increased AV
block during which flutter waves may be
unmasked.
Reference 2

20.  82 year old male with COPD presents with
fevers and green sputum.

21.  occurs in respiratory disease and reflects an aberrant foci
of atrial excitation
 typically a transitional rhythm between frequent premature
atrial complexes (PACs) and atrial flutter / fibrillation
 At least 3 distinct P-wave morphologies in the same lead
 Thought to be a result of:
◦ Right atrial dilatation (from cor pulmonale)
◦ Increased sympathetic drive
◦ Hypoxia and hypercarbia
◦ Beta-agonists
Reference 2

22.  65 year old man with a history of ischaemic
heart disease is found unresponsive.
What do we do?

23.  65 year old man with a history of ischaemic
heart disease presents with SOB
What do we do?

24.  Treatment of FBI:
Unstable
◦ DC Cardioversion!
 Stable
◦ IV chemical cardioversion e.g procainamide
◦ Avoid all AV nodal blockers!
 Adenosine
 Verapamil
 Diltiazem
 Beta-blockers
 Digoxin
 Amiodarone (has both beta-blocker and Ca-channel blocker
properties)

25.  50 year old lady comes to the emergency department from
her husband’s funeral with a sensation of ‘fluttering’ in her
chest. She is feeling very anxious.
What do we do?

26. 2 main types. AVNRT (left) and AVRT (right)
Reference 2

27.  60 year old male presents with chest pain and
suddenly stops talking during ECG
What do we do?

28.  18 year old male signs up for the army and
has a routine ECG

29.  Due to a mutation in the cardiac sodium channel
gene
 Type 1 Coved ST segment elevation >2mm in >1
of V1-V3 followed by a negative T wave
 Type 2: 2mm of saddleback shaped ST elevation
 Diagnosis must be coupled with clinical criteria:
VF, FHX sudden death, Syncope
 The only proven therapy is an implantable
cardioverter – defibrillator (ICD)

30.  24 year old male collapses 1 minute in to his
run. Has happened previously

31.  Number one cause of sudden cardiac death in
young athletes. Annual mortality is estimated at
1-2 %
 Left ventricular hypertrophy (LVH), occurring in
the absence of any inciting stimulus such as
hypertension or aortic stenosis
 ECG Signs:
◦ LVH
◦ deep, narrow (“dagger-like”) Q waves in the lateral (V5-
6, I, aVL) and inferior (II, III, aVF) leads
◦ P mitrale
◦ T wave inversion laterally in apical HCM

32.  A 25 year old man presents with a collapse which
occurred as he was playing in a football match. He
has suffered episodes of fainting in the past

33.  PR interval <120ms
 Delta wave – slurring slow rise of initial
portion of the QRS
 QRS prolongation >110ms
 Look for T waves in anterior leads. Pre-
excitations simulates RVH

34. 16 year old boy presents to clinic
after an episode of syncope

35.  Calculate the QTc
◦ Bazetts formula (med calc)
◦ Fredericas formula
 The QT shortens at faster heart rates
 The QT lengthens at slower heart rates
 Bazetts formula not as accurate outside HR 60-100BPM
 QTc is prolonged if > 440ms in men or > 460ms in
women
 QTc > 500 is associated with increased risk of torsades de
pointes
 A useful rule of thumb is that a normal QT is less than half
the preceding RR interval

36.  Causes:
 Hypokalaemia
 Hypomagnesaemia
 Hypocalcaemia
 Hypothermia
 Myocardial ischemia
 Post-cardiac arrest
 Raised intracranial pressure
 Congenital long QT syndrome
 DRUGS

38.  K+ channelopathy
 QTc (<300-350)
 Short QT interval
 Lack of the normal changes in QT interval
with heart rate
 Peaked T waves, particularly in the precordial
leads
 Short or absent ST segments
 Episodes of atrial or ventricular fibrillation

39. 20 year old male presents with palpitations

40.  inherited disorder associated
with paroxysmal ventricular
arrhythmias and sudden cardiac death.
 Epsilon wave (most specific finding, seen in
30% of patients)
 T wave inversions in V1-3 (85% of patients)
 Slurred S wave (V1-3): 95% of patients
 Localised QRS widening of 110ms in V1-3
 Paroxysmal episodes of ventricular
tachycardia

41.  1st degree:
 2nd degree
◦ Mobitz 1
Mobitz 2
3rd Degree

42.  60 year old male presents to ED after
syncope. History of CKD.

43.  Increased extracellular potassium reduces
myocardial excitability.
 leads to suppression of impulse generation
by the SA node and reduced conduction
system, resulting in bradycardia, conduction
blocks and ultimately cardiac arrest.

44.  Serum potassium > 5.5 mEq/L is associated with repolarization
abnormalities:
◦ Peaked T waves
 Serum potassium > 6.5 mEq/L is associated with progressive
paralysis of the atria:
◦ Lengthen PR, P wave widens and flattens
 Serum potassium > 7.0 mEq/L is associated with conduction
abnormalities and bradycardia:
◦ Prolonged QRS interval with bizarre QRS morphology
◦ High-grade AV block with slow junctional and ventricular escape rhythms
◦ Sinus bradycardia or slow AF
◦ Development of a sine wave appearance (a pre-terminal rhythm)
 Serum potassium level of > 9.0 mEq/L causes cardiac arrest due
to:
 Asystole
 Ventricular fibrillation
 PEA with bizarre, wide complex rhythm

46.  26 year old male with Conns syndrome
presents with muscle weakness and pains
Hypokalaemia

47.  A 29 year old BIBA in arrest. Initial ECG done
prior to arrest was this

48.  ECG done 2 weeks ago by GP was found. She
had presented with chest pain.

49.  An 18 year old lady is found collapsed at
home. When you see her she has a GCS of 10
and you notice that her pupils are dilated.

50.  A,B,C,D,E (ventilation may be required)
◦ Bloods including paracetamol level; Activated
charcoal if within 8hrs of ingestion
 Sodium bicarbonate (50ml of 8.4%)
◦ Give if any arrhythmia or QRS widening
 Further options:
◦ If seizures: benzodiazepines

51. 55 year old male with hx of PCKD presents with GCS 3

52.  82 year old male presents with syncope

53. 84 year old male with hx of CCF plus IHD presents post syncope

54.  Important ECG findings in Syncope:
◦ Paroxysmal or sustained dysrhythmia on monitoring in clinic
◦ Non-sinus rhythm of any sort
◦ Nonspecific intraventricular conduction delay (QRS > 100 ms without left
or right bundle branch pattern)
◦ Left bundle branch block or left anterior or posterior hemiblock
◦ ECG signs of coronary ischemia
◦ Long QT syndrome - QTc > 440-450 msec in men or > 460 msec in
women
◦ Brugada sign - right bundle branch block and anterior ST elevation
◦ Left ventricular hypertrophy in someone with no reason to have it and/or
Q waves in II, III, aVF, V5, and V6
◦ Pre-excitation syndromes (PR interval < 120 msec) with or without delta
wave
◦ Can Quick BRAD Walk Home

55.  1. OME – Oxford Medical Education: ECGs and
knowledge
 2. Life in the fast lane – ECG diagnoses A-Z
 3. Prospective validation of the San Francisco
Syncope Rule to predict patients with serious
outcomes. AAEM 2013.
Image from ref 1