Systematic ECG analysis

SYSTEMATIC ECG ANALYSIS

REFERENCESECG

• previous CME talks

• Life In The Fast Lane

• Dr Smiths ECG blog

• Google Image Search

• Time on the Floor

COMPONENTSECG

• Rate

• Rhythm

• Axis

• P

• PR

• QRS

• QT

• ST

• T

• Delta

• Epsilon

• Osborne

• U

THE NORMAL ECG

• Rhythm: <10% variation in R-R intervals

• Rate: 60 - 100bpm

• Axis -30 - -90

• P Waves

• 0.2-0.3mV

• 0.06 – 0.12s

• Upright in I, II, aVF, V2- V6

• Inverted in aVR

• Varies in III, aVLSinus origin

• PR Interval

• 0.12 – 0.2s

• Q Waves

• Small in I, II, aVL, V5, V6

• QRS Complex

• <0.12s

• ST Segment

• Isoelectric

• T Waves

• <2/3 height of preceding R wave

• 0.5mm in I, II, III

• <10mm in V1 – V6

• Same direction as preceding R wave

• U Waves

• <25% of T wave

• Same direction as T wave

• QTc

• <440ms in males

• <460ms in females

THE NORMAL ECGGet used to knowing what normal looks like.

RATE

• Small square: 0.04sec

• Big square: 0.2sec

• If it looks fast

• 1500/small squares

• If it looks slow/normal

• 300/big squares

• If irregular, count complexes on rhythm strip x 6 for average

RHYTHM

• Regular

• Irregular

• Regularly Irregular

• Irregularly Irregular

• P-wave:

• Are they present?

• Are they regular?

• Is there a P for every QRS?

• Do the P-waves look similar?

• PR Interval

• Long? >0.12s

• Short? <0.06s

• Are the PR intervals Consistent?

• QRS

• Long? >0.12s

• Similar in appearance to each other?

• Atrial, AVNRT, Accessory Pathways, Junctional rhythms, Ventricular rhythmas

RHYTHMRegular

?P waves? PR interval? - long, short, consistent?P for every QRS?

QRS? Normal Sinus Rhythm

RHYTHMRegular


QRS? 1st degree Heart Block

HEART BLOCKRHYTHM

RHYTHMRegular


QRS? Atrial Fibrillation

RHYTHMRegular


QRS? Atrial Flutter 4:1 block

RHYTHMRegular


QRS? Atrial Flutter

TO ILLUMINATE THE P WAVESRHYTHM

CLASSIC LEAD PLACEMENT THEN WITH LEWIS LEADSRHYTHM

RHYTHMRegular


QRS? SVT - AVNRT

SUPRA VENTRICULAR TACHYCARDIASRHYTHM

• A tachydysrhythmia originating above the Bundle of His

• Sinus tachy, Atrial flutter, Atrial Fibrillation

• Atrio-Ventricular Re-Entry Tachycardia (AVRT)

• AV Nodal Re-Entry Tachycardia (AVNRT)

• Automatic Junctional Tachycardia

AVNRT VS AVRTRHYTHM

• Left - AVNRT

• Right - AVRT (accessory pathway)

AVNRT

• Slow and fast pathway within the AV Node

• If a PAC arrives whilst a pathway is refractory, it can allow the other pathway to set up a re-entry pathway within the AV node

ACCESSORY PATHWAYSAVRT

• Orthodromic • Antidromic

RHYTHMRegular


QRS? AVRT - Orthodromic

RHYTHMRegular


QRS? AVRT - Antidromic

VT VS SVT WITH ABERRANT CONDUCTIONRHYTHM

• VT is more likely when

• absence of typical RBBB/LBBB morphology

• Very broad complexes (>160ms)

• AV dissociation

• Fusion beats - when sinus and ventricular beat fuse to cause hybrid complex

• Entirely positive or entirely negative complexes

throughout V1-6

• Brugada’s - Distance from onset of QRS to nadir of S-wave is >100ms

• Josephson’s Sign - notching near nadir of S-wave

• RSR complexes w/ Left Rabbit Ear being taller. In contrast Right Rabbit Ear is taller in RBBB


• Fusion then capture

• Positive concordance


• Brugada

• Josephson’s

• RSR in V1

RHYTHMRegular


QRS? Ventricular Fibrillation

RHYTHMRegular


QRS? Polymorphic VT

QUIZ TIME!!!

RHYTHM QUIZ1.

RHYTHM QUIZ2.

RHYTHM QUIZ3.

RHYTHM QUIZ4.

RHYTHM QUIZ5.

RHYTHM QUIZ6.

RHYTHM QUIZ7.

RHYTHM QUIZ8.

RHYTHM QUIZ9.

RHYTHM QUIZ10.

WHAT IS A LICHTENBERG FIGURE?RHYTHM QUIZ

11.

ATRIAL FLUTTER 3:1 BLOCKRHYTHM QUIZ

1.

AVRT - ORTHODROMIC WPWRHYTHM QUIZ

2.

MOBITZ 1 - WENCKEBACHRHYTHM QUIZ

3.

VT THEN BIGEMINYRHYTHM QUIZ

4.

TORSADES DE POINTESRHYTHM QUIZ

5.

ATRIAL FIBRILLATIONRHYTHM QUIZ

6.

VENTRICULAR FIBRILLATIONRHYTHM QUIZ

7.

AIVR OR JUNCTIONAL RHYTHM WITH LBBBRHYTHM QUIZ

8.

COMPLETE HEART BLOCKRHYTHM QUIZ

9.

SHORT PR - WPWRHYTHM QUIZ

10.

WHAT IS A LICHTENBERG FIGURE?RHYTHM QUIZ

11.

They are branching electric discharges that sometimes appear on the surface or in the interior of insulating

materials.

AXIS

AXIS

• Normal Axis = -30 - +90• Left Axis = <-30• Right Axis = >+90• Extreme Right Axis = -90 -

180

AXIS

• QRS Positive Deflection = axis toward that lead

• QRS Negative Deflection = axis away from the lead

• QRS Isoelectric = Axis perpendicular to that lead

DIFFERENTIALSAXIS

• RAD• RVH• RV Strain• Lateral STEMI• COPD• HyperK+• Na+ Blockade• WPW• Normal Paeds

ECG

• LAD• LVH• LBBB• Inf. MI• Ventricular

pacing• WPW

• Extreme Axis

• HyperK+• Ventricular

arrhythmias• Severe RVH

QUIZ TIME!!!

AXIS QUIZ1.

AXIS QUIZ2.

AXIS QUIZ3.

AXIS QUIZ4.

AXIS QUIZ5.

AXIS QUIZ6.

WHAT IS COMMOTIO CORDIS?

AXIS QUIZ7.

LEFT AXIS DEVIATIONAXIS QUIZ

1.

NORMAL AXISAXIS QUIZ

2.

LEFT AXIS DEVIATION - LVHAXIS QUIZ

3.

LEFT AXIS DEVIATIONAXIS QUIZ

4.

RIGHT AXIS DEVIATION - RVHAXIS QUIZ

5.

RIGHT AXIS DEVIATIONAXIS QUIZ

6.

WHAT IS COMMOTIO CORDIS?AXIS QUIZ

7.

Commotio cordis (Latin, "agitation of the heart") is an often lethal disruption of heart rhythm that occurs as a result of a blow to the area directly over the

heart (the precordial region), at a critical time during the cycle of a heart beat causing cardiac arrest. It is a form of ventricular fibrillation (V-Fib), not

mechanical damage to the heart muscle or surrounding organs, and not the result of heart disease. The fatality rate is about 65% even with prompt CPR

and defibrillation, and more than 80% without.

THE P WAVE• P Wave

• Width <120ms

• Amplitude

• <2.5mm limb leads

• <1.5mm Precordial

• V1 biphasic

• aVF inverted

THE P WAVE

THE PR INTERVAL

• PR Interval

• 120-200ms

• Long - any heart block

• Short - WPW, pre-excitation

• Elevation/Depression - Pericarditis

THE QRS COMPLEX

NEGATIVE DEFLECTION BEFORE THE R WAVETHE Q WAVE

• They are pathological if:

• >40ms wide

• >2mm deep

• >0.25% QRS

• Present in leads V1-V3

• >2mm in leads III/avR can be a normal variant

NEGATIVE DEFLECTION BEFORE THE R WAVETHE Q WAVE

• They are pathological if:• >40ms wide• >2mm deep• >0.25% QRS• Present in leads V1-V3

• >2mm in leads III/avR can be a normal variant

FIRST POSITIVE DEFLECTION AFTER THE P-WAVETHE R WAVE

• Causes of a dominant R wave in V1• Normal in paediatric and young adults• RVH• RBBB• Posterior STEMI• WPW• Dextrocardia• HOCM• Dystrophy

• Myotonic• Duchennes

RVH


• Dominant R wave in aVR• Poisoning - Na-Channel Blockers• Dextrocardia• Incorrect lead placement• Commonly in VT TCA poisoning


• Poor R Wave Progression - R wave <4mm in V3• Prior anteroseptal MI• LVH• Inaccurate lead placement• Can be normal variant

THE QRS

• LBBB - depolarisation activated from RV via right bundle then to LV via left bundle

• RBBB - Right ventricular depolarisation is delayed and so depolarisation spreads from left to right

BUNDLE BRANCH BLOCK

LEFT VENTRICULAR HYPERTROPHYTHE QRS

• Muscle wall thickens

• Increased S wave in Right sided leads

• Increased R wave in Left sided leads

• Prolonged depolarisation

• Repolarisation abnormalities in lateral leads

• Causes

• HTN

• AR/AS

• MR

• HOCM

LEFT VENTRICULAR HYPERTROPHYTHE QRS

RIGHT VENTRICULAR HYPERTROPHYTHE QRS

• Right Axis

• Dominant R in V1 >7mm

• Dominant S in V6 >7mm

• RV Strain - ST depression in V1-4 and inferiorly

• Causes

• PE

• Chronic Lung Dx

• Pulm. HTN

• Mitral Stenosis

• Congenital Heart Dx

RIGHT VENTRICULAR HYPERTROPHYTHE QRS

QUIZ TIME!!!

QRS QUIZ1.

QRS QUIZ2.

QRS QUIZ3.

QRS QUIZ4.

QRS QUIZ5.

QRS QUIZ6.

THE HEART OF A BLUE WHALE IS ABOUT AS BIG AS A…?

QRS QUIZ7.

A. Volkswagen BeetleB. Piano

C. Average PersonD. Bus

ANTERIOR Q WAVESQRS QUIZ

1.

RBBBQRS QUIZ

2.

LVHQRS QUIZ

3.

POOR R WAVE PROGRESSION - LAD OCCLUSIONQRS QUIZ

4.

PATHOLOGICAL Q WAVES - AMI 1/52 PRIORQRS QUIZ

5.

LBBBQRS QUIZ

6.

THE HEART OF A BLUE WHALE IS ABOUT AS BIG AS A…?

QRS QUIZ7.

A. Volkswagen BeetleB. Piano

C. Average PersonD. Bus

REPRESENTS INTERVAL BETWEEN VENTRICULAR DEPOLARISATION AND REPOLARIZATION

THE ST SEGMENT

SGARBOSSA CRITERIAST SEGMENT

MODIFIED SGARBOSSAST SEGMENT

MODIFIED SGARBOSSAST SEGMENT

ST depression >0.3 height of R wave

QUIZ TIME!!!

DONDE ESTA LA STEMI?ST QUIZ

1.

ST QUIZ2.

ST QUIZ3.

ST QUIZ4.

ST QUIZ5.

ST QUIZ6.

ST QUIZ7.

AN OCTOPUS HAS HOW MANY HEARTS?

ST QUIZ8.

LATERAL STEMIST QUIZ

1.

INFERIOR STEMIST QUIZ

2.

PERICARDITISST QUIZ

3.

POSTERIOR STEMIST QUIZ

4.

ANTERIOR STEMIST QUIZ

5.

INFERIOR STEMIST QUIZ

6.

ANTEROLATERAL STEMIST QUIZ

7.

AN OCTOPUS HAS HOW MANY HEARTS?ST QUIZ

8.

3!!!Two brachial hearts on either side of the body that oxygenate blood by pumping it through the gills

One systemic heart pumps blood from gills to the rest of the body

START OF THE Q TO THE END OF TYOU QT

• Represents Ventricular de- and repolarization

• Inversely proportional to heart rate

• 440ms for males, 460 for females

• QT >500ms increases risk of TDP

VENTRICULAR REPOLARIZATIONT WAVES

• Can be inverted in V1 and aVR

• Flat, Biphasic, Inverted, Peaked, Tented

• Look for dynamic change

• Don’t miss Wellen’s Syndrome

• Hyperacute - early STEMI, prinzmetal Angina

• Inverted T - can be normal, MI, BBB, Hypertrophy, PE, HOCM

• Biphasic - Ischaemia, Hypokalaemia

WELLENS’ SYNDROMET WAVES

• Inverted or Biphasic T-waves in V2-3 (in patients presenting with ischaemic chest pain) highly specific for critical stenosis of LAD

Type A Type B

DE WINTERS - LAD OCCLUSIONT WAVES

• Peaked anterior T waves with ascending limb of T wave commencing below isoelectric line - tall, prominent, symmetric

• Upsloping ST depression in precordial leads

DELTA WAVEOTHER WAVES

• WPW - pre excitation

U WAVEOTHER WAVES

• Thought to be delayed depolarisation of Purkinje Fibers

• Prominent U waves: Bradycardia, Hypo-Ca/Mg, Hypothermia, LVH, HOCM, Digoxin, Class Ia, III antiarrhythmics

• Inverted U waves: CAD, HTN, Valvular HD, Congenital HD, Hyperthyroid

OSBORNE WAVEOTHER WAVES

• Positive deflection at J point

• Hypothermia, Normal Variant, HypercalcaemiaHypothermia Temp 32

QUIZ TIME!!!

CENTRAL CHEST PAINQUIZ TIME

1.

QUIZ TIME2.

CENTRAL CHEST PAIN AND SHORTNESS OF BREATHQUIZ TIME

3.

QUIZ TIME4.

CHEST PAINQUIZ TIME

5.

CHEST PAINQUIZ TIME

6.

QUIZ TIME7.

WHAT IS A SHARKS SIXTH SENSE?BONUS POINTS: NAME THE ORGAN THAT DETECTS THIS

QUIZ TIME8.

DE WINTERS T WAVES - LAD OCCLUSIONQUIZ TIME

1.

HYPERKALAEMIA K+ 9.0 - PEAKED T, WIDE QRS, SINE WAVE APPEARANCE

QUIZ TIME2.

MASSIVE PE - EXTREME RAD, S1Q3T3, RBBB, TWI V1-4QUIZ TIME

3.

HYPOTHERMIA TEMP 26 - OSBORN WAVESQUIZ TIME

4.

LBBB - CONCORDANT ST DEPRESSION V3 - STEMIQUIZ TIME

5.

PERICARDITISQUIZ TIME

6.

WIDE QRS, TACHYCARDIA, POSITIVE R WAVE IN AVR - TCA OVERDOSE

QUIZ TIME7.

WHAT IS A SHARKS SIXTH SENSE?BONUS POINTS: NAME THE ORGAN THAT DETECTS THIS

QUIZ TIME8.

They can sense electricity!

Ampullae of Lorenzini

THANK YOU!

Health & Medicine

Systematic ECG analysis