Embed Size (px)
Citation preview
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) 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
The criteria for complete LBBB include:1. QRS duration > 0.12 second2. A wide deep QS complex in V13. 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 QRS
3.T wave inversions in leads with tall R waves
4. Left axis deviation
5. Voltage criteria for left ventricular hypertrophy (LVH) should be usedwith 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) The PR interval is prolongedb) The QRS axis is normalc) There is normal R wave progressiond) There is a complete right bundle branch blocke) There is evidence of right ventricular hypertrophy
a) The PR interval is prolongedb) The QRS axis is normalc) There is normal R wave progressiond) There is a complete right bundle branch blocke) There is evidence of right ventricular hypertrophy
Criteria for RVH1. RAD- axis is perpendicular to AVF~1802. 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 coronaryarteriography2. Urgent angiographic CT scan to excludepulmonary embolism3. Consider this ECG as a normal variant andreassure the patient accordingly4. Nothing, this is a typical artifact originatingfrom a poor connection of the Wilson terminalto the ground5.None of the above
ECGs similar to this one can be seen in1. 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 ray2.2D ECHO3.Holter recording4.CT scan5.Cardiac MRI
Case 5:
This ECG from an 18 year old male shows all of the following EXCEPT?
a) Normal variant early repolarization patternb) Physiologic sinus arrhythmiac) Normal AV conductiond) Left axis deviatione) Transition zone in lead V3
a) Normal variant early repolarization pattern
b) Physiologic sinus arrhythmia
c) Normal AV conduction
d) Left axis deviation
e) 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 6This ECG from a 23 year-old female is most consistent with which diagnosis?
a) Left atrial abnormalityb) Anterior ischemiac) Normal variant T wave inversions V1-V2d) Hypokalemiae) Left ventricular hypertrophy
a) Left atrial abnormalityb) Anterior ischemiac) Normal variant T wave inversions V1-V2d) Hypokalemiae) Left ventricular hypertrophy
ECG manifestations of acute myocardial ischemia
• ST elevationNew 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
Notice the rather typical relative absence of ST deviation.
Acute RCX occlusion
Old/recent posterior-lateral MIprominent R in V2 (a 'reciprocal Q wave')
Acute inferior-posterior-lateral MI
Acute inferior and right ventricular MIElevation of V4R
Left main diseaseDiffuse 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) Complete right bundle branch block
b) Complete left bundle branch block
c) Wolff-Parkinson-White pre-excitation (right sided bypass tract)
d) Left anterior fascicular block
e) Left posterior fascicular block
ST elevation in LVH
ST elevation during high potassium levels
Diffuse ST elevation in pericarditis
Non-ST Elevation Infarction
Note the ST depression and T-wave inversion in leads V2-V6.
Here’s an ECG of an evolving non-ST elevation MI:
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 ConductionSinoatrial 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?
V1
For RBBB the wide QRS complex assumes a
unique, virtually diagnostic shape in those
leads overlying the right ventricle (V1 and V2).
“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).
Broad,
deep S
wavesNormal
