No Slide Title · 2014-08-15 · New ST elevation at the J-point in two contiguous leads with the...

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

Acute posterior MI

more about this topic on ECGpedia...

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