Download d) Left axis deviation

ECG Workshop
Nezar Amir
Case one
A 61-year-old man with a history of hypertension and congestive
heart failure presents to the emergency department with shortness of
breath after eating breakfast. All of the following statements about his
ECG are correct EXCEPT:
a) The QRS axis is normal
b) The rhythm is sinus tachycardia
c) The PR interval is within normal limits
d) There is a complete left bundle branch block
e) The voltage in the chest leads meets criteria for left ventricular
hypertrophy
a)
b)
c)
d)
e)
The QRS axis is normal
The rhythm is sinus tachycardia
The PR interval is within normal limits
There is a complete left bundle branch block
The voltage in the chest leads meets criteria for left ventricular hypertrophy
The criteria for complete LBBB include:
1. QRS duration > 0.12 second
2. A wide deep QS complex in V1
3. A wide tall R wave in V6
The correct answer is d) There is no left bundle
branch block (LBBB)
LVH
1.Prominent voltage in the chest leads and selected limb lead
2.Widened
3.T
4.
wave
QRS
inversions
Left
in
leads
with
axis
tall
R
waves
deviation
5. Voltage criteria for left ventricular hypertrophy (LVH) should be used
with caution. Commonly used voltage criteria include one or
1.
SV1
+
RV5
or
V6
>
35
mm
(3.5
mV)
2.
RaVL
>
11
mm
(1.1
mV)
3. For men: SV3 + RaVL > 28 mm (2.8 mV)
4. For women: SV3 + RaVL > 20 mm (2.0 mV)
Case two
A 26-year-old woman comes to the emergency department
complaining of increased shortness of breath. Which one of
the following statements is true concerning her admission
ECG?
a)
b)
c)
d)
e)
The PR interval is prolonged
The QRS axis is normal
There is normal R wave progression
There is a complete right bundle branch block
There is evidence of right ventricular hypertrophy
a)
b)
c)
d)
e)
The PR interval is prolonged
The QRS axis is normal
There is normal R wave progression
There is a complete right bundle branch block
There is evidence of right ventricular hypertrophy
Criteria for RVH
1. RAD- axis is perpendicular to AVF~180
2. qR in V1
3. ST-T changes in V1-V4 in keeping with RV strain pattern
Correct Answer is e
RV hypertrophy occurs over time in response to pressure or volume
overload in conditions such as;
1. Primary pulmonary hypertension
2. Chronic obstructive pulmonary disease (COPD)
3. Pulmonic stenosis
4. Atrial septal defect (ASD).
This patient was diagnosed with PAH
Case 3; The above ECG is from a 64 year old Caucasian male referred by the
primary care physician to the cardiac outpatient clinic because of a very
abnormal ECG. The patient is asymptomatic, without any sort of chest pain,
dyspnea, palpitations, or previous syncope or dizzy spells. The BP is 130/80
mmHg and there are not murmurs on auscultation.
What would you do?
1. Urgent hospital admission for coronary
arteriography
2. Urgent angiographic CT scan to exclude
pulmonary embolism
3. Consider this ECG as a normal variant and
reassure the patient accordingly
4. Nothing, this is a typical artifact originating
from a poor connection of the Wilson terminal
to the ground
5.None of the above
ECGs similar to this one can be seen in
1. Athletes of African or Afro-American origin without the phenotype of
hypertrophic cardiomyopathy: our patient is Caucasian and is not an
athlete, but a 64 year old male in whom his primary care physician
obtained a routine ECG
2. Severe hypertensive heart disease: the blood pressure in this patient
was normal
3. Valvular aortic stenosis: there were no heart murmurs on
auscultation
4. Hypertrophic cardiomyopathy: the absence of murmurs should
prompt us to consider a non-obstructive hypertrophic
cardiomyopathy
cMR
Case 4; The above ECG is from a 53 year old male with a history of high blood pressure
for the last couple of years. He is overweight and has mild hyperglycemia. He is
referred by the primary care physician to the cardiac outpatient clinic because of a
history of episodes of palpitations during the last 3 months, unrelated to exercise, of a
very short duration, two or 3 times per month. On auscultation there is a 2/6 systolic
murmur along the left sternal border and a wide splitting of the second heart sound.
What would you do first?
1.Chest X ray
2.2D ECHO
3.Holter recording
4.CT scan
5.Cardiac MRI
Case 5:
This ECG from an 18 year old male shows all of the
following EXCEPT?
a)
b)
c)
d)
e)
Normal variant early repolarization pattern
Physiologic sinus arrhythmia
Normal AV conduction
Left axis deviation
Transition zone in lead V3
a)
b)
c)
d)
e)
Normal variant early repolarization pattern
Physiologic sinus arrhythmia
Normal AV conduction
Left axis deviation
Transition zone in lead V3
d) Left axis deviation
This ECG shows a normal variant that is commonly referred to as early
repolarization pattern." There are ST elevations in leads V2-V6 and in
some of the limb leads. Slight notching of the terminal QRS (V4) is often
seen in conjunction with this pattern. The ST segment retains its normal
upward concavity. The QRS axis here is normal (about +30 degrees). The
QRS transition zone (R=S) is in lead V3, a normal finding. AV conduction is
normal, indicated by the normal PR interval (about 0.14 sec.) The slight
variation in heart rate is due to physiologic (respiratory) sinus arrhythmia.
Case 6
This ECG from a 23 year-old female is most consistent with
which diagnosis?
a)
b)
c)
d)
e)
Left atrial abnormality
Anterior ischemia
Normal variant T wave inversions V1-V2
Hypokalemia
Left ventricular hypertrophy
a)
b)
c)
d)
e)
Left atrial abnormality
Anterior ischemia
Normal variant T wave inversions V1-V2
Hypokalemia
Left ventricular hypertrophy
ECG manifestations of acute
myocardial ischemia
• ST elevation
New ST elevation at the J-point in two
contiguous leads with the cut-off points: ≥
0.2 mV in men or ≥ 0.15 mV in women in
leads V2-V3 and/or ≥ 0.1 mV in other leads.
• ST depression and T-wave
changes
New horizontal or down-sloping ST
depression > 0.05 mV in two contiguous
leads: and/ or T inversion ≥ 0.1 mV in two
contiguous leads with prominent R-wave or
R/S ratio ≥ 1.
ECG infarct
Common causes of ST shift
Infarct localisation
•
•
•
•
•
•
Left main artery occlusion:
o diffuse ST-depression with ST
elevation in AVR
o very high risk
Anterior wall:
o ST elevation V1-V4. LAD. (often
tachycardia)
Inferior wall:
o ST elevation II, III, AVF.
o 80% RCA (elevation III>II; depression
> I or in AVL), or RCX ( in 20%).
(often bradycardic due to sinus node
or AV node ischemia)
Right ventricle infarct:
o ST elevation in V4R.
Posterior wall:
o high R and ST-depression in V1-V3
Lateral wall:
o ST elevation in lead I, AVL, V6.
o LAD (D-branch)
V4 right helps diagnose right ventricular
involvement (in RCA occlusion)
Acute inferior MI
Old inferior MI:
prominent Q waves in II, III & AVF
Acute anterior-lateral infarct
Acute antero-septal MI
Recent (days old) anterior MI (after PCI)
Old anterior-septal MI
Acute posterior MI
more about this topic on ECGpedia...
Acute RCX occlusion
Notice the rather typical relative absence of ST deviation.
Old/recent posterior-lateral MI
prominent R in V2 (a 'reciprocal Q wave')
Acute inferior-posterior-lateral MI
Acute inferior and right ventricular MI
Elevation of V4R
Left main disease
Diffuse ST depression and elevation in AVR
ST elevation in the absence of an aMI
Some other conditions that can cause ST elevation are:
• Pericarditis/myocarditis.
• Left ventricular hypertrophy (LVH)
• Physiological/benign ST elevation
• Cardiac aneurysm
• Hyperkalemia
• LBBB
• HCM
ST elevation in LBBB
a)
b)
c)
d)
e)
Complete right bundle branch block
Complete left bundle branch block
Wolff-Parkinson-White pre-excitation (right sided bypass tract)
Left anterior fascicular block
Left posterior fascicular block
ST elevation in LVH
ST elevation during high potassium levels
Diffuse ST elevation in pericarditis
Non-ST Elevation Infarction
Here’s an ECG of an evolving non-ST elevation MI:
Note the ST
depression and
T-wave
inversion in
leads V2-V6.
Question:
What area of
the heart is
infarcting?
Anterolateral
Bundle Branch Blocks
Bundle Branch Blocks
Turning our attention to bundle branch blocks…
Remember normal
impulse conduction is
SA node 
AV node 
Bundle of His 
Bundle Branches 
Purkinje fibers
Normal Impulse Conduction
Sinoatrial node
AV node
Bundle of His
Bundle Branches
Purkinje fibers
Bundle Branch Blocks
So, depolarization of the
Bundle Branches and
Purkinje fibers are seen as
the QRS complex on the
ECG.
Therefore, a conduction
block of the Bundle
Branches would be
reflected as a change in
the QRS complex.
Right
BBB
Bundle Branch Blocks
With Bundle Branch Blocks you will see two changes on the
ECG.
1. QRS complex widens (> 0.12 sec).
2. QRS morphology changes (varies depending on ECG lead, and if it is
a right vs. left bundle branch block).
Bundle Branch Blocks
Why does the QRS complex widen?
When the conduction
pathway is blocked it
will take longer for
the electrical signal
to pass throughout
the ventricles.
Right Bundle Branch Blocks
What QRS morphology is characteristic?
For RBBB the wide QRS complex assumes a
unique, virtually diagnostic shape in those
leads overlying the right ventricle (V1 and V2).
V1
“Rabbit
Ears”
Left Bundle Branch Blocks
What QRS morphology is characteristic?
For LBBB the wide QRS complex assumes a
characteristic change in shape in those leads
opposite the left ventricle (right ventricular
leads - V1 and V2).
Normal
Broad,
deep S
waves