4. 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
6. 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
7. 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
8. RHYTHM
Regular? P waves? PR interval? - long, short, consistent?P for every QRS?
QRS? Normal Sinus Rhythm
9. RHYTHM
Regular? P waves? PR interval? - long, short, consistent?P for every QRS?
QRS? 1st degree Heart Block
19. 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
21. RHYTHM
Regular? P waves? PR interval? - long, short, consistent?P for every QRS?
QRS? AVRT - Orthodromic
22. RHYTHM
Regular? P waves? PR interval? - long, short, consistent?P for every QRS?
QRS? AVRT - Antidromic
23. VT VS SVT WITH ABERRANT CONDUCTION
RHYTHM
• 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
24. VT VS SVT WITH ABERRANT CONDUCTION
RHYTHM
• Fusion then capture
• Positive concordance
25. VT VS SVT WITH ABERRANT CONDUCTION
RHYTHM
• Brugada
• Josephson’s
• RSR in V1
26. RHYTHM
Regular? P waves? PR interval? - long, short, consistent?P for every QRS?
QRS? Ventricular Fibrillation
27. RHYTHM
Regular? P waves? PR interval? - long, short, consistent?P for every QRS?
QRS? Polymorphic VT
50. 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.
52. AXIS
• Normal Axis = -30 - +90
• Left Axis = <-30
• Right Axis = >+90
• Extreme Right Axis = -90 - 180
53. AXIS
• QRS Positive Deflection =
axis toward that lead
• QRS Negative Deflection =
axis away from the lead
• QRS Isoelectric = Axis
perpendicular to that lead
69. 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.
70. THE P WAVE
• P Wave
• Width <120ms
• Amplitude
• <2.5mm limb leads
• <1.5mm Precordial
• V1 biphasic
• aVF inverted
74. NEGATIVE DEFLECTION BEFORE THE R WAVE
THE 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
75. NEGATIVE DEFLECTION BEFORE THE R WAVE
THE 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
76. FIRST POSITIVE DEFLECTION AFTER THE P-WAVE
THE 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
77. FIRST POSITIVE DEFLECTION AFTER THE P-WAVE
THE R WAVE
• Dominant R wave in aVR
• Poisoning - Na-Channel Blockers
• Dextrocardia
• Incorrect lead placement
• Commonly in VT
TCA poisoning
78. FIRST POSITIVE DEFLECTION AFTER THE P-WAVE
THE R WAVE
• Poor R Wave Progression - R wave <4mm in V3
• Prior anteroseptal MI
• LVH
• Inaccurate lead placement
• Can be normal variant
79. 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
80. LEFT VENTRICULAR HYPERTROPHY
THE 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
82. RIGHT VENTRICULAR HYPERTROPHY
THE 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
119. 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
120. START OF THE Q TO THE END OF T
YOU QT
• Represents Ventricular de- and repolarization
• Inversely proportional to heart rate
• 440ms for males, 460 for females
• QT >500ms increases risk of TDP
121. VENTRICULAR REPOLARIZATION
T 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
122. WELLENS’ SYNDROME
T 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
123. DE WINTERS - LAD OCCLUSION
T WAVES
• Peaked anterior T waves with ascending limb of T wave
commencing below isoelectric line - tall, prominent, symmetric
• Upsloping ST depression in precordial leads
125. U WAVE
OTHER 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
126. OSBORNE WAVE
OTHER WAVES
• Positive deflection at J point
• Hypothermia, Normal Variant, Hypercalcaemia
Hypothermia Temp 32