Transcript Advanced ECG Interpretation

12 Lead EKG Interpretation
12-lead EKG interpretation
has been a lifelong partner
of the
Emergency Physician
in patient assessment
Many EP’s, though,
are not STARS
at 12 lead EKG interpretation
WHY?????
Because most EKG courses
are too long,
too boring,
and teach absolutely unnecessary
and unrememberable stuff
in ways that
make students just
regurgitate the material
What am I
NOT talking about?
Advanced rhythm assessment
Ventricular tachycardia assessment
Vtach vs. SVT assessment
Block
Augustus Waller
Augustus Waller
Einthoven
Netherlands – ECG 1895
Einthoven
String Galvanometer
Einthoven
Fowler’s Prime Directive
of Cardiac Emergencies:
Some systole is better
than no systole at all
Pulseless Rhythms
CPR, Shock, Intubate
with CPR, Epi q 3, Shock,
Amio or Lidocaine then ??
CPR, Shock, Intubate with
CPR, Epi q 3, Shock,
Amio or Lidocaine then ??
Intubate, IV, Epi q 3,
Consider Atropine,
Look for cause
Second point:
Much of what we call
“12 lead interpretation”
is in fact actually
rhythm strip interpretation.
…such as, for example, the evaluation
of AV block,
which can usually be done in one,
or at most, two leads
Third point:
AXIS INTERPRETATION
IS BORING!!
As the lead
sees the impulse growing
(or “coming toward it”),
the machine records
an upward deflection
Positive
As the lead sees the
impulse coming then going
(or “going by the lead”),
the machine records
an isoelectric deflection
Positive
As the lead sees the
impulse coming then going
(or “going by the lead”),
the machine records
an isoelectric deflection
Positive
Lead I
Lead II
+
Lead III
+
+
The EKG Basic Limb Leads
+
I
II
III
+
+
Lead I is “horizontal”, and is arbitrarily
established at “0 Degrees”
+
Lead II is 60 degrees
down from Lead 1
and is arbitrarily
established at
“Positive 60 Degrees”
+
+
Lead III is
120 degrees
from Lead I, and
is arbitrarily
established at
“Positive
120 Degrees”
+
Lead I
Augmented Limb Leads
avL
avR
Lead II
avF
+
+
Lead II
Added by
Goldberger
in 1942
+
Lead I
+
Augmented Limb Leads
Lead II
+
Lead II
Frontal Plane
+
+
+
V6
V5
V4
V1
V2
V3
Added by AHA and the
Cardiac Society of Great Britain 1938
The Leads may be moved
to the center of the chest
I
+
I
II
III
III
+
II
+
+
+
+
Axis is based on the direction of
the heart’s depolarization
+
I
II
III
+
+
I
+
I
II
II
III
+
+
III
I
+
I
II
II
III
+
+
III
I
+
I
II
II
III
+
+
III
Rhythm strip interpretation
has been a standard
for emergency medicine
since the inception of
the monitor
Basic Rhythm
Strip Interpretation
•Rate
•Rhythm
•P Waves
•PR Interval
•QRS Complex
•ST Segment
•T Wave
•U Wave
•Summary
“Cherchez la P”
Rate
Rhythm
P
PR
Axis
Hypertrophy
Infarction
QRS
ST
T
U
Assessment
Since serious rhythm
disturbances are
the most important issue
(like VF, VT, asystole),
then if you see a serious
rhythm disturbance
proceed with
rhythm strip interpretation
FIRST!!!
Normal EKG?
Understanding the Anatomy
Is the Key
The coronary circulation
The coronary
arteries supply
the three main
walls of
the heart
+
Lead I
Augmented Limb Leads
avL
avR
Lead II
avF
+
+
Lead II
Anterior
Lateral
Inferior
Considering
Ischemia
and
Injury
The EKG leads
that are positive
closest to the
site of the infarction
will show
ST segment elevation
Convex upwards is
an injury pattern,
meaning infarction
Concave upwards
is probably
early repolarization
The EKG leads
that are positive
on the other side of the
heart from the infarction
will show reciprocal
ST segment depression
The Basic Fundamental of
12 Lead EKG Interpretation
You CAN’T understand
12 leads without understanding
the concept of
“Grouped Leads”
Grouped Leads
Relate DIRECTLY
to Cardiac Anatomy
So, if you understand the anatomy,
you can quickly look at a 12 lead and
understand it immediately!
INFERIOR
INFERIOR
II, III, aVF
LATERAL
ANTERIOR
Inferior wall M.I. =
Right Coronary
infarction (usually)
Elevated ST segments
in II, III, and avF, with
reciprocal depression
in I, avL, and the chest leads
Inferior wall M.I. =
Acute Inferior Wall
Myocardial Infarction
Lateral wall M.I. =
Left Circumflex
Coronary infarction
Elevated ST segment
in I, L, and V6 with
reciprocal depression
in II, III, and avF
Acute Lateral Wall
Myocardial Infarction
Inferior Wall M.I. vs. Lateral Wall M.I.
Normal EKG, right?
Normal vs. abnormal
Left Coronary Artery
The EKG leads
that are positive
closest to the
site of the infarction
will show
ST segment elevation
Acute Anterior Wall
Myocardial Infarction
Acute Anterior Wall
Myocardial Infarction
Early Repolarization
Pattern
Okay, smarty pants:
What exactly
would leads I, II, and III
show in the case of an
anterior (LAD) infarction?
HMMMMM????
Reciprocal depression
in all three leads!!
All three leads are on the
other side of the heart from
the infarction!
Having a 12 lead machine
around to keep an eye on the
tracings is a good idea sometimes...
Monitoring For Ectopy
on a 12 Lead EKG
Sometimes the tracings can be
quite hard to interpret
…and sometimes
almost worthless...
…sometimes VERY interesting...
Acute Hyperkalemia
Acute Hypokalemia
The problem
with
letting the
machine
read the tracing???
…but sometimes
the machine can
be RIGHT!!!
Don’t forget that 12 leads
can let us forget
to analyze the rhythm!!!
Ventricular
Hypertrophy
Left Ventricular
Hypertrophy
Left Axis Deviation
Deep S wave in V1
Large R wave in V5
V1 plus V5 adds up
to more than 35 millimeters
And/Or aVL 11 mm or greater
Right Ventricular
Hypertrophy
Look to the RIGHT side
of the heart to find it,
namely V1
Finding Ventricular
Hypertrophy
Always look at V1
Finding Ventricular
Hypertrophy
Large R wave in V1 = RVH
Deep S wave in V1 = LVH
Corollary: If the complex is
wider than 0.12 seconds,
this is probably a bundle branch block
and not ventricular hypertrophy
Bundle Branch Block
Normal Conduction
Left Bundle Branch Block
V6
Right Bundle Branch Block
V1
Bundle Branch Block
Positive Deflection
Rabbit Ears in V1
with wide complex
Positive Deflection
in V6
with wide complex
Right
Bundle
Branch
Block
Left
Bundle
Branch
Block
Right Bundle Branch Block
Left Bundle Branch Block
Left Anterior Hemiblock
Brugada Syndrome
Brugada Syndrome
Brugada syndrome is a disorder
characterized by coved or saddle-shaped
ST-segment elevation
in leads V1 through V3 on ECG
Brugada Syndrome
Brugada syndrome is most common
in people from Asia.
The reason for this observation is not
yet fully understood but may be due
to an Asian-specific sequence in the
promoter region of SCN5A (Bezzina, 2005).
In Asia (eg, the Philippines, Thailand, Japan),
Brugada syndrome seems to be the
most common cause of natural death
in men younger than 50 years.
Brugada syndrome is 8-10 times
more prevalent in men than in women,
Brugada Syndrome
Brugada Syndrome
Brugada Syndrome
Brugada Syndrome
Wellen’s Syndrome
Wellens' syndrome is a pattern of electrocardiographic
T-wave changes associated with critical, proximal
left anterior descending (LAD) artery stenosis.
The syndrome is also referred
to as LAD coronary T-wave syndrome.
Syndrome criteria include T-wave changes
plus a history of anginal chest pain
without serum marker abnormalities;
patients lack Q waves and significant
ST-segment elevation; such patients show
normal precordial R-wave progression.
Wellens Syndrome is an easy to identify cardiac
syndrome which indicates a critical high grade
occulsion of the proximal LAD.
If not identified and properly treated the mean time
from onset of symptoms to
extensive anterior wall MI is 8.5 days
Wellen’s Syndrome
Now, kiddies…
IT’S EXAM
TIME!!
Crushing Chest Pain with Diaphoresis 58 y/o
Acute Chest Pain in 118 Year Old Patient
Diffuse ST Segment Elevation in Chest Pain
in a middle-aged lady who has recently had a cold
Check the axis and the PR Interval…
Older guy, feeling crummy…
Older guy having palpitations and lightheadedness
Middle-aged guy found semi-conscious
with weak radial pulse
What is this patient’s blood pressure?
Prompt and accurate analysis
of the ECG requires
anatomical understanding
and continual practice
About the time you think
you’re getting real good at
ECG analysis, you’ve realized
that you may have forgotten
nearly as much as you
ever learned:
Remember Wellens and Brugada!
Promise yourself
(and your patients)
that a lifetime of
continual study and
refresher courses
will accompany
your practice