Killer ECGs

James Le Fevre

The Ultimate Killer ECG

(conscious) VF

The ultimate Killer ECG

Asystole (Remember fine VF)

Leads not corrected properly

Brugada Syndrome

Long QT syndrome

Short QT syndrome

Arrhythmogenic right ventricular dysplasia (ARVD)Wolff-Parkinson White Syndrome (WPW)Repetitive Monomorphic Ventricular Tachycardia

Catecholaminergic polymorphic VT

Idiopathic Fascicular Ventricular Tachycardia (Verapamil Sensitive Ventricular Tachycardia)

Inherited Arrythmia Syndromes

Hypertrophic obstructive cardiomyopathy

Aortic dissection

Submassive PE/Massive PE

Intracerebral bleed/SAH

Severe Hyperkalemia

Commotio cordis

Other presentations

Risk Assessment and Disposition

Medical Risk to Our Patient

Medicolegal Risk to Us

Opportunity to Save a Life

Why learn this ?

Lead II• The QTc (Short QT Syndrome/Long QT Syndrome)

Lead V2 (V1-V3)• T Wave Inversion (Brugada/ARVD)• ST Elevation (Brugada)• T wave Notching (LQTS)• Epsilon Waves (ARVD)• QRS > 110ms in V1-V3 (ARVD)

The Money Leads

Brugada Syndrome

A ‘Channelopathy’• Sodium channel mutation

The typical patientBrugada syndrome is genetically determined • Now over 60 different mutations identified• 50% spontaneous

Brugada Syndrome

Unmasked/Augmented by• Fever• Ischaemia• Multiple drugs• Hypokalaemia• Hypothermia• Post DC Cardioversion

Brugada Syndrome

Type I ECG WITH• Documented VF or polymorphic VT

• FHx SCD <45 years of age

• Coved-type ECGs in family members

• Inducible VT (EPS)

• Syncope

• Nocturnal agonal respiration

Brugada Syndrome – Diagnostic Criteria

Type 1‘coved-type’STE > 2mm &TwIType 2STE > 2mmTw +ve/biphasicType 3STE < 2mmAny T wave

Brugada Syndrome

Studies small, evidence level low

Symptomatic Type I – Admit

Asymptomatic Type I – Debatable (Need EPS)

Type 2/3 ECG Patterns – Outpatient EPS/Sodium blocker challenge

Patients with Type 2/3 ECG patterns than convert to Type I with Flecainide have unclear prognosis

Definitive: ICD, Quinidine if ICD not feasible

Brugada Syndrome - Disposition

Take home messages• Look at lead V2 closely in anyone with syncope• The diagnosis is in leads V1-V3

• STE

• T wave changes

• RBBB/IRBBB

Brugada Syndrome

Long QT Syndrome

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

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 polymorphic VT/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

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

Normal QTc range

Upper limit children/adolescents• 0.46

Upper limit women• 0.46

Upper limit men• 0.45

Long QT Syndrome

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

• Macroscopic T-wave electrical alternans (1 Point)

• Notched T-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

Long QT Syndrome

Macroscopic T-wave Alternans (1 Point)

Long QT Syndrome

Long QT Syndrome

Notched T waves (1 Point)

Long QT Syndrome

Notched T waves – 1 Point

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

Assess risk based on underlying cause

Generally monitor till resolved

If very long QTc consider Magnesium sulfate prophylactically

Replacing electrolytes is good supportive care

If Torsade de Pointes or polymorphic VT• 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 in Torsades with Congenital LQTS

is absolutely contraindicated

Acquired Long QT Syndrome - Disposition

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 for T wave alternans (esp. V1-V3)

• Look for notched T waves

• Look for slow heart rate for age

Long QT Syndrome

Short QT Syndrome

Short QT interval ≤ 320 ms with no change with HR, tall, peaked T 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

• 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

A distinctive electrocardiographic feature of the short QT syndrome is the appearance of tall peaked T waves, similar to those encountered with hyperkalemia

Brugada-like in genotypes 4-5

QT interval is fixed independent of heart rate

Short QT Syndrome

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

QT Syndromes – Diagnostic Criteria

Reproduced from ViskinViskin 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]

Take Home Message• Be very worried if the QTc is <320ms• Very rare

Short QT Syndrome

Arrhythmogenic Right Ventricular Dysplasia

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 Right Ventricular Dysplasia

Major and Minor criteria• 2 Major OR• 1 Major 2 minors OR• 4 minors

Horribly complicated

Arrhythmogenic Right Ventricular Dysplasia – Diagnostic Criteria

Palpitations

Syncope

Cardiac arrest

Often precipitated by exercise

Family history of SCD

Hayden Roulston has this condition

Arrhythmogenic Right Ventricular Dysplasia – Clinical features

Epsilon wave (specific, sensitivity 30%)

T-wave inversions V1-V3 (85% sensitive)

Prolonged S-wave upstroke of 55ms in V1-3 (95% sensitive)

Localised QRS widening of 110ms in V1-V3

Paroxysmal LBBB VT

Frequent LBBB PVCs (>1000/24Hr typically)

Arrhythmogenic Right Ventricular Dysplasia – ECG Features

Epsilon waves

Arrhythmogenic Right Ventricular Dysplasia

Arrhythmogenic Right Ventricular Dysplasia – Prolonged S wave upstroke in V2

Arrhythmogenic Right Ventricular Dysplasia – Localised QRS > 110ms V1-V3

Epsilon wave

Localised QRS > 110ms

T-wave inversions V1-V3

Arrhythmogenic Right Ventricular Dysplasia – ECG Features

LBBB VT (i.e. has a RV origin)

Echo (sensitive, less specific, cheaper)

MRI (Specific and sensitive but expensive)

Combination Echo/MRI ideal

Histology• Least patient-oriented diagnostic technique

Arrhythmogenic Right Ventricular Dysplasia – Imaging

? 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 Right Ventricular Dysplasia – Disposition

Take home messages• Look for epsilon waves (Best seen V1-V3)• Beware the young patient with very frequent LBBB extrasystoles• Again, examine V1-V3 closely (TWI, QRS >110)

Arrhythmogenic Right Ventricular Dysplasia

Genetic Predisposition

Mostly due to Calcium ryanodine channel mutations

Thought to affect up to 1 in 10,000 people

Polymorphic VT 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 polymorphic VT

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

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

Type A• Upright positive delta wave in all precordial leads with a resultant R greater than S

amplitude in lead V1

Wolff-Parkinson-White syndrome

Type B

• negative delta wave

• QRS complex mostly negative in leads V1 and V2 and becomes positive in transition to the lateral leads resembling a left bundle-branch block

Wolff-Parkinson-White syndrome

WPW - SVTO

RT

HO

DR

OM

IC (9

0%)

WPW - SVTA

NT

IDR

OM

IC (1

0%)

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

Atrial fibrillation with antidromic WPWAdenosine 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

No longer considered a specific diagnosis in the ‘electrophysiologic study’ era

Lown-Ganong Levine Syndrome

Take Home Messages• If the tachycardia is wide complex, treat it as such

• If in doubt, consult, and/or use electricity

WPW

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

Some important physical findings• A fourth heart sound

• Displaced, forceful, enlarged apex beat

• Systolic murmur increased on valsalva

Hypertrophic cardiomyopathy

ECG Findings• ST-T wave abnormalities and LVH

• Axis deviation

• BBB

• Ectopic atrial rhythm

• Q waves anterolaterally

• P wave abnormalities

Hypertrophic cardiomyopathy

Hypertrophic cardiomyopathy

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 Leads V1-V3 looking for:• Is the QRS >110ms in V1-V3 (AVRD) ?• Are there inverted T-waves (Brugada, ARVD) ?• Is there ST elevation (Brugada) ?• Is there macroscopic T-wave alternans (LQTS) ?• Are there notched T-waves (LQTS) ?• Are there epsilon waves (ARVD) ?

Is this a Killer ECG ?

• ? 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 ?

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% of VT 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

Handy Tips

QUIZ

ARVD

WPW – Type A

LQTS

HOCM

STEMI

Brugada (Type 2)

Electrical alternans (Tamponade)

Brugada Type II

Hyperkalaemia – Patient about to die

Brugada Type I