This document provides an overview of various cardiac arrhythmia syndromes including Brugada syndrome, long QT syndrome, short QT syndrome, arrhythmogenic right ventricular dysplasia, Wolff-Parkinson-White syndrome, and hypertrophic cardiomyopathy. It discusses the clinical features, ECG findings, diagnostic criteria, and disposition for each condition. Key advice includes carefully examining leads V1-V3 for abnormalities, being aware of rare conditions like short QT syndrome, and consulting cardiology when these complex syndromes are suspected.
9. A ‘Channelopathy’
• Sodium channel mutation
The typical patient
Brugada syndrome is genetically determined
• Now over 60 different mutations identified
• 50% spontaneous
Brugada Syndrome
10. Unmasked/Augmented by
• Fever
• Ischaemia
• Multiple drugs
• Hypokalaemia
• Hypothermia
• Post DC Cardioversion
Brugada Syndrome
11. Type I ECGWITH
• DocumentedVF or polymorphicVT
• FHx SCD <45 years of age
• Coved-type ECGs in family members
• InducibleVT (EPS)
• Syncope
• Nocturnal agonal respiration
Brugada Syndrome – Diagnostic
Criteria
12. Type 1
‘coved-type’
STE > 2mm &
TwI
Type 2
STE > 2mm
Tw +ve/biphasic
Type 3
STE < 2mm
AnyT wave
Brugada Syndrome
13. Studies small, evidence level low
SymptomaticType I – Admit
AsymptomaticType I – Debatable (Need EPS)
Type 2/3 ECG Patterns – Outpatient EPS/Sodium blocker challenge
Patients withType 2/3 ECG patterns than convert toType I with Flecainide have
unclear prognosis
Definitive: ICD, Quinidine if ICD not feasible
Brugada Syndrome - Disposition
14. Take home messages
•Look at leadV2 closely in anyone with syncope
• The diagnosis is in leadsV1-V3
• STE
• T wave changes
• RBBB/IRBBB
Brugada Syndrome
16. LQTS may be expected to occur in 1 in 10,000 individuals.
Prolongation of the QT interval on ECG
Propensity for:
Ventricular tachyarrhythmias
Sudden Cardiac death
Collapse
Long QT can also be acquired
• (MI / IHD / Drugs / Electrolytes)
Congenital Long QT Syndrome
17. LQTS is caused by mutations of the genes for cardiac potassium, sodium, or
calcium ion channels
Essentially, repolarisation takes longer, the QT interval lengthens and
predisposes the individual to polymorphicVT/torsade de pointes/VF and SCD
Depending on the type of mutation present,
sudden cardiac death may happen during:
Exercise
emotional stress
during sleep
Congenital Long QT Syndrome
18. Presenting features
• Presentation with cardiac arrest or syncope
• After a family member suddenly dies/has an arrhythmia
• After a routine ECG is taken
Physical examination
• Excessive bradycardia for age
• Congenital deafness
• Syndromic constellations
Long QT Syndrome – Hx/Exam
19. Normal QTc range
Upper limit children/adolescents
• 0.46
Upper limit women
• 0.46
Upper limit men
• 0.45
Long QT Syndrome
20. Diagnosis
• List of criteria max score 9, score of >3 gives high probability
• 2-3 = intermediate probability
• Realm of cardiologists
• ECG clues for us
• QTc length most important (≥ 480ms = 3 pts, 460-470ms = 2 pts, 450ms Male = 1 pt
• MacroscopicT-wave electrical alternans (1 Point)
• NotchedT-waves (1 Point)
• Low heart rate for age (0.5 Points in children)
•2.5% of healthy people have a long QT
•10-15% of CLQTS patients have a n0rmal QT interval
Long QT Syndrome
25. Admit if ? Congenital LQTS and symptomatic
Discuss if ? Congenital LQTS and asymptomatic
Treatment – Congenital
• Depends on type and risk assessment
• Beta blockers
• ICD
• Educate and Investigate family
• (Medic alert bracelet, carry around sheet with drugs that
doctor should avoid, train family in CPR)
Congenital Long QT Syndrome -
Disposition
26. Assess risk based on underlying cause
Generally monitor till resolved
If very long QTc consider Magnesium sulfate prophylactically
Replacing electrolytes is good supportive care
IfTorsade de Pointes or polymorphicVT
• Magnesium and overdrive pace with isoprenaline
Acquired versus congenital:
Torsades in acquired caused by not enough stimulation
Torsades in congenital caused by too much stimulation
Overdrive pacing inTorsades with Congenital LQTS
is absolutely contraindicated
Acquired Long QT Syndrome -
Disposition
27. Take Home Messages
• Measure the QTc (Take interest if >450 men >460 women, worry
if you did not need to measure it to notice it)
• Look forT wave alternans (esp.V1-V3)
• Look for notchedT waves
• Look for slow heart rate for age
Long QT Syndrome
29. Short QT interval ≤ 320 ms with no change with HR, tall,
peakedT wave, structurally normal heart
5 mutations found so far
Autosomal dominant inheritance
Think of this in young people with atrial fibrillation and with
syncope/cardiac arrest
Short QT Syndrome
30. • Genotypes 1-3
• Gain of function in potassium efflux channels
• QTc <320ms
• Genotypes 4-5
• Loss of function in L-type Calcium channels
• Brugada like
• QTc <360ms
• Digoxin toxicity can also cause shortened QT and
arrythmia
Short QT Syndrome
31. A distinctive electrocardiographic feature of the short QT
syndrome is the appearance of tall peakedT waves, similar
to those encountered with hyperkalemia
Brugada-like in genotypes 4-5
QT interval is fixed independent of heart rate
Short QT Syndrome
32. QTc < 330 ms in males or <340 ms in female diagnostic
QTc < 360 ms in males or <370 ms in females when
supported by symptoms or FHx
Short QT Syndrome – Diagnostic
Criteria
33. QT Syndromes – Diagnostic Criteria
Reproduced from Viskin
Viskin S. The QT interval: too long, too short or just right. Heart Rhythm.
2009 May;6(5):711-5. Epub 2009 Mar 3. [PMID: 19389656] [Full text]
34. Take Home Message
• Be very worried if the QTc is <320ms
• Very rare
Short QT Syndrome
36. ARVD is due to a type of cardiomyopathy, which is possibly familial in some
patients.
Fibrofatty infiltrated Hypokinetic areas
The prevalence of ARVD is estimated to be 1 case per 5,000 population
The death rate associated with arrhythmia is estimated to be 2.5% per year
More common in men than women (3:1)
More common with Italian/Greek descent
Arrhythmogenic RightVentricular
Dysplasia
37. Major and Minor criteria
• 2 Major OR
• 1 Major 2 minors OR
• 4 minors
Horribly complicated
Arrhythmogenic RightVentricular
Dysplasia – Diagnostic Criteria
44. Echo (sensitive, less specific, cheaper)
MRI (Specific and sensitive but expensive)
Combination Echo/MRI ideal
Histology
• Least patient-oriented diagnostic technique
Arrhythmogenic RightVentricular
Dysplasia – Imaging
45. ? ARVD with high risk features (syncope due to cardiac
arrest, recurrent arrhythmia, FHx) : Admit
? ARVD asymptomatic (i.e. ECG suggestive) : Discuss
Treatment:
• High-risk features: Urgent ICD Placement
• No high-risk features: Sotalol
• Persistent arrhythmias: Ablation
• Heart failure: Standard Rx including transplant
Arrhythmogenic RightVentricular
Dysplasia – Disposition
46. Take home messages
• Look for epsilon waves (Best seenV1-V3)
• Beware the young patient with very frequent LBBB extrasystoles
• Again, examineV1-V3 closely (TWI, QRS >110)
Arrhythmogenic RightVentricular
Dysplasia
47. Genetic Predisposition
Mostly due to Calcium ryanodine channel mutations
Thought to affect up to 1 in 10,000 people
PolymorphicVT due to emotional upset/physical
activity (and therefore catecholamines)
Estimated to cause up to 15% of SCD in young people
ECG clues
• Sinus bradycardia, prominent U-waves
Not a diagnosis that one can make in the emergency
department
Catecholaminergic polymorphicVT
48. Due to extra ‘Accessory pathways’ or connections between the atrium and
ventricle
WPW syndrome affects approximately 0.15-0.2% of the general population. Of
these individuals, 60-70% have no other evidence of heart disease.
Kent bundle
Risk of SCD much lower than in the other discussed syndromes (0.6%)
Wolff-Parkinson-White syndrome
49. Broad spectrum of presentations
• CP/SOB/SCD/Palpitations/Syncope
• Routine ECG diagnosis
Classic:
• Shortened PR interval (<0.12)
• QRS >0.12
• Delta wave
• Secondary ST-T changes in opposite direction to delta wave
Wolff-Parkinson-White syndrome
50. Type A
• Upright positive delta wave in all precordial leads with a resultant R greater than S
amplitude in leadV1
Wolff-Parkinson-White syndrome
51. Type B
• negative delta wave
• QRS complex mostly negative in leadsV1 andV2 and becomes positive in transition
to the lateral leads resembling a left bundle-branch block
Wolff-Parkinson-White syndrome
54. Circus movement tachycardias
• Vagal maneuvers
• Adenosine is Safe, Diltiazem/verapamil second line
• Give calcium if using verapamil
• Electricity if unstable
• Etomidate +/- fentanyl works well for sedation
• Give 100J initially (2J/kg in children)
WPW - Orthodromic
55. Atrial fibrillation with antidromicWPW
Adenosine and other AV blockers absolutely Contraindicated
• Sedate and Shock is the safest approach (100J first)
• Must slow the abnormal pathway NOT the node (i.e. fundamentally
different to normal AF treatment)
• If treated like conventional AF,VF can be the outcome
• Procainamide can be used
WPW – Antidromic/AF
56. No longer considered a specific diagnosis in the ‘electrophysiologic study’ era
Lown-Ganong Levine Syndrome
57. Take Home Messages
• If the tachycardia is wide complex, treat it as such
• If in doubt, consult, and/or use electricity
WPW
58. Hypertrophic cardiomyopathy (HCM) is a genetic disorder that is typically
inherited in an autosomal dominant fashion with variable penetrance and
variable expressivity
Presents with SCD, arrythmia, heart failure, dizziness, angina, syncope,
palpitations
Hypertrophic cardiomyopathy
59. Some important physical findings
• A fourth heart sound
• Displaced, forceful, enlarged apex beat
• Systolic murmur increased on valsalva
Hypertrophic cardiomyopathy
62. Review ECG in General
• Is the QTc >450 (men) or >460 (women) (LQTS) ?
• Is the heart rate too low for age (LQTS) ?
• Is the QTc <320 (Short QT Syndrome) ?
• Are there frequent LBBB PVCs (ARVD) ?
• Think of HOCM (LVH criteria+/-ST-T changes, BBB, Q-waves)
• Is the PR <0.12 ? Are there delta waves (WPW) ?
Review LeadsV1-V3 looking for:
• Is the QRS >110ms inV1-V3 (AVRD) ?
• Are there invertedT-waves (Brugada, ARVD) ?
• Is there ST elevation (Brugada) ?
• Is there macroscopicT-wave alternans (LQTS) ?
• Are there notchedT-waves (LQTS) ?
• Are there epsilon waves (ARVD) ?
Is this a Killer ECG ?
63. • ? ARVD with high risk features: Admit on monitor,
inpatient Echo (+/- MRI)
• ? ARVD incidentally on ECG : Consult
• ? Long QT Syndrome: Admit on monitor
• ? Short QT Syndrome: Admit on monitor, Publish
• ? HOCM with symptoms: Admit for inpatient Echo
• VT/?VT: Admit on monitor
• WPW, orthodromic SVT, no AF, stable: Discharge with
advice and f/u, EPS can help risk stratify for SCD
• WPW, antidromic SVT, or AF, or both: Use electricity,
discuss with cardiology first if stable, refer cardiology
Disposition ?
64. Giving an amp of calcium prior to verapamil and diltiazem in SVT can decrease
hypotension without decreasing efficacy of cardioversion
Adenosine in asthma is a relative contraindication, avoid if active wheeze or history
of severe asthma, consider starting with 3mg
? 5% ofVT is adenosine sensitive, Benefit may well outweigh risk. A response to
adenosine does NOT prove SVT with aberrancy
QTc is helpful in differentiating Anterior STEMI from Benign early repolarisation as
the QTc increases in Anterior STEMI
Some patients are terrified of how adenosine makes them feel, give them a bit of
midazolam first (it may increase the chance of cardioversion also)
A gentle carotid massage can differentiate Aflutter with a 2:1 block from a slow SVT
(don’t do if a bruit present, be prepared for a long pause)
Etomidate 2-4mL +/- 25mcg fentanyl iv in an unstable patient for DCCV is a good
option
Ketamine is the next best, as Etomidate appears to be in short supply
HandyTips
Risk assessment of the well-looking patient with a symptom that may be relatively benign but can be deadly A large part of EM practice Medical risk versus medico-legal risk Opportunity to genuinely save a life
Brugada syndrome is most common in people from Asia Brugada syndrome is 8-10 times more prevalent in men than in women Second leading cause of death in males <40 after trauma Mean age of sudden death is 41 Previously described as SUNDS (Sudden unexplained nocturnal death syndrome in SEA)
frequency of gene mutation is equal, therefore, higher penetrance in men Brugada syndrome most commonly affects otherwise healthy men aged 30-50 years
Fever can
Major Criteria Right ventricular dysfunction Severe dilatation and reduction of RV ejection fraction with little or no LV impairment Localized RV aneurysms Severe segmental dilatation of the RV Tissue characterization Fibrofatty replacement of myocardium on endomyocardial biopsy Conduction abnormalities Epsilon waves in V1 - V3. Localized prolongation (>110 ms) of QRS in V1 - V3 Family history Familial disease confirmed on autopsy or surgery Minor Criteria Right ventricular dysfunction Mild global RV dilatation and/or reduced ejection fraction with normal LV. Mild segmental dilatation of the RV Regional RV hypokinesis Tissue characterization Conduction abnormalities Inverted T waves in V2 and V3 in an individual over 12 years old, in the absence of a right bundle branch block (RBBB) Late potentials on signal averaged EKG. Ventricular tachycardia with a left bundle branch block (LBBB) morphology Frequent PVCs (> 1000 PVCs / 24 hours) Family history Family history of sudden cardiac death before age 35 Family history of ARVD
