Electrocardiograms (Ecg)

Front 1

Causes of prolonged QRS interval

Back 1

Hypothermia
Metabolic/electrolyte abnormalities (acidosis, hyperkalemia)
Sodium channel blocking drugs
Non specific intraventricular conduction delay (e.g. LVH, congenital)
BBB
Paced rhythm
Ventricular ectopy
Pre-excitation (e.g. WPW)

Front 2

Causes of slow atrial fibrillation

Back 2

Medication toxicity
-Digoxin
-Beta-blockers
-Calcium channel blockers
Hypothermia

Front 3

Stages of pericarditis

Back 3

I: Widespread ST elevation and PR depression with reciprocal changes in aVR (1-2 weeks)

II: Normalization of ST with generalized t wave flattening (1-3 weeks)

III: Flattened T waves --> Inverted t waves (3 - several weeks)

IV: ECG normalizes (several weeks later)

Front 4

Prominent R wave in V1 (R:S >1)

Back 4

WPW
Posterior MI
RBBBB or iRBBB
Ventricular ectopy
RVH
Acute RV Dilatation/strain (e.g. PE)
HCM
Sodium channel blocking drugs
Hyperkalemia
Dextrocardia
Misplaced leads

Front 5

DDx of osborn j waves

Back 5

Normal variant
Hypercalcemia
Neurological insult
Hypothermia

Front 6

ECG findings of elevated ICP/neurological insults

Back 6

Diffuse TWI and enlargements
Brady and tachy arrhythmia
Non-specific ST changes
Ischemic ST changes

Front 7

ECG features of pericarditis

Back 7

-Widespread concave ST elevation and PR depression throughout most limb and precordial leads
-Reciprocal ST depression and PR elevation in aVR
-Sinus tachycardia
-ST elevation in V6 : T wave in V6 >0.25 suggests pericarditis rather than benign early repolarization

Front 8

ECG features of hypertrophic cardiomyopathy

Back 8

-Left atrial enlargement
-LVH with associated ST changes and TWI
-"Dagger" Q waves in lateral and inferior leads
- +/- signs of WPW

NB - prone to a fib, SVT, VT

Front 9

Differntial diagnosis of causes of Left ward axis deviation

Back 9

LBBB
Paced rhythm
WPW
Inferior MI (due to Q waves in aVF)
LVH
Hyperkalemia
Normal variant
Left anterior fasicular block

Front 10

Left anterior fasicular block

Back 10

-Leftward axis deviation
-r'S in inferior leads (II,III,aVF)
-qR in laterial leads (I, aVL)

Front 11

ECG criteria for brugada syndrome

Back 11

I: Coved ST elevation >2mm in at least of one V1-V3 with a negative t Wave

II: Saddleback ST elevation >2mm in at least one of V1-V3

III: Either of above with <2mm of ST elevation

often seen with RBBB or iRBB pattern

Front 12

ECG findings to search for in syncope

Back 12

(1) Acute coronary syndrome
(2) Tachycardia/Bradycardia and AV blocks
(3) Intervals
- Short PR suggesting WPW/Pre-excitation
- Long or Short QT interval
(4) Hypertrophic cardiomyopathy
(5) Brugada syndrome
(6) Arrhythmogenic right ventricular dysplasia

Front 13

Arrhythmogenic right ventricular dysplasia

Back 13

-Epsilon waves (small positive deflection at end of QRS)
-TWI in V1-V3
-QRS wide in V1-V3
-Prolonged S in V1-V3

Front 14

Classic triad of WPW

Back 14

Short or absent PR interval
Widened QRS
Delta wave

Can see ST or T wave changes discordant with the dominant delta wave/QRS

Front 15

ECG features suggestive of benign early repolarization

Back 15

-ST elevation concave upwards that is most prominent in precordials, especially V2-V3 and sometime inferior leads
-No reciprocal ST changes
-J point Notching at the terminal QRS (especially V4)
-Large asymmetric T waves in same leads
-No dynamic ST changes
-ST elevation : T wave ration in V6 <0.25

Front 16

ECG findings in Hyperkalemia

Back 16

Peaked t waves
QRS widening
Prolonged PR
Flattening to loss of P waves
Advanced AV blocks and sinus pauses
Pseudo ACS patterns (ST changes)
New BBBs
Sine wave pattern

Front 17

Differential diagnosis of right axis deviation

Back 17

RVH
Dextrocardia
Lateral MI (due to q Wave in Lead I)
Ventricular ectopy
Hyperkalemia
Sodium channel blocking drugs
Acute or chronic right ventricular strian
Thin adult with a horizontal heart (normal variant)
Lead misplacement

LPFB

Front 18

Left posterior fasicular block

Back 18

RAD
r'S in lateral leads (I and avL)
qR in inferior leads (II, III, avF)

Front 19

Low QRS voltages

(i) Definition
(ii) Differential diagnosis

Back 19

Definition
QRS <5mm in all limb leads OR < 10mm in all precordial leads

Differential Diagnosis:
Low power
-Myxedema
-Infiltrative disease
-End stage cardiomyopathy

Conduction to surface block
-Pericardial fluid
-Pleural fluid
-Obesity
COPD

Front 20

ECG findings in hypothermia

Back 20

Osborn waves
Sinus bradycardia
Junctional rhythm
Prolonged intervals
Slow irregular a fib
Ventricular fibrillation
Asystole

Front 21

Causes of Inverted t waves

Back 21

Coronary artery disease
Neurological insult
Hyperkalemia
WPW
Pulmonary HTN
Abnormal repolarization
-LBBB
-RBBB
-Paced rhythm
-LVH
-RVH

Front 22

Causes of prolonged QT interval

Back 22

Hypothermia
Hypokalemia (due to u waves)
Hypocalcemia
Hypomagnesemia
Acute coronary syndrome
Elevated ICP
Sodium channel blocking drugs
Congenital
Other medications
-Macrolide antibiotics
-Fluroquionolones
-Methadone
-Metoclopramide
-Ondansetron
-Anti-psychotics
-Anti-depressants

Front 23

Differential diagnosis of diffuse ST segment elevation

Back 23

Large STEMI
Pericarditis
Myocarditis
Ventricular aneurysm
Hyperkalemia
Coronary vasospams
Brugada
LVH
LBBB
Paced rhythm
Benign early repolarization

Post electrical cardioversion

Acute cerebral hemorrhage

Front 24

ECG features that suggest Acute Myocardial Infarction versus Pericarditis

Back 24

Supporting MI:
-Reciprocal changes
-Tombstone or horizontal ST elevation
-ST elevation in lead III > lead II
-new Q waves
-QR-T "checkmark" complex

Supporting pericarditis
-Pronounced PR depression in all leads
-Friction rub

Front 25

PAILS Reciprocal Changes

Back 25

(1) With posterior STEMI see anterior depression
(2) with anterior STEMI see inferior depression
(3) with inferior STEMI see lateral depression
(4) Lateral STEMI inferior depression

Front 26

ECG Manifestations of Acute Myocardial Ischemia

Back 26

ST elevation
New ST elevation at the J point in two contiguous leads with the cut-points:
0.1 mV in all leads other than leads V2–V3 where the following cut
points apply: 0.2 mV in men 40 years or older; 0.25 mV in men less than 40 years, or 0.15 mV in women.

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.

Front 27

Diagnostic criteria for Wellens

Back 27

• Deeply-inverted or biphasic T waves in V2-3 (may extend to V1-6)
• Isoelectric or minimally-elevated ST segment (< 1mm)
• No precordial Q waves
• Preserved precordial R wave progression
• Recent history of angina
• ECG pattern present in pain-free state
• Normal or slightly elevated serum cardiac markers

Concerning for critical LAD Stenosis

Front 28

De Winter's T waves

Back 28

• Tall, prominent, symmetric T waves in the precordial leads
• Upsloping ST segment depression >1mm at the J-point in the precordial leads
• Absence of ST elevation in the precordial leads
• ST segment elevation (0.5mm-1mm) in aVR
• “Normal” STEMI morphology may precede or follow the deWinter pattern

STEMI Equivalent/LAD occlusion

Front 29

Anterior MI

Back 29

V1 - V4 STE

Can extend to lateral

II, III, aVF STD

LAD Occlusion

Front 30

Worst infarct location for prognosis

Back 30

Anterior MI

Front 31

ECG pattern for left main coronary artery occlusion

Back 31

widespread ST depression with ST elevation in aVR ≥ V1

Front 32

Lateral MI

Back 32

I, aVL, V5-V6 STE

Can have STD in III, aVF, V1

Variable blood supply LAD, circumflex, RCA so variable extension

Front 33

Inferior MI

Back 33

II, III, avF -> STE

I, AVL reciprocal STD

Most commonly right dominant circulation so RCA occlusion but can also be Left Circumflex

Front 34

Complications of inferior MI

Back 34

AV Block

RV extension

Posterior extension

Front 35

Differentitating culprit artery in inferior MI

Back 35

RCA Occlusion

• ST elevation in lead III > lead II
• Presence of reciprocal ST depression in lead I
• Signs of right ventricular infarction: STE in V1 and V4R

Left circumflex occlusion

• ST elevation in lead II = lead III
• Absence of reciprocal ST depression in lead I
• Signs of lateral infarction: ST elevation in the lateral leads I and aVL or V5-6

Front 36

Posterior MI

Back 36

STE V7-V9

Reciprocal changes in V1 - V3:

(1) horizontal ST segment depression

(2) a tall, upright T wave

(3) a tall, wide R wave

(4) an R wave amplitude/S wave amplitude ratio greater than 1

Culprit lesion = RCA or left circumflex

Front 37

Posterior Leads

Back 37

• V7 – Left posterior axillary line, in the same horizontal plane as V6.
• V8 – Tip of the left scapula, in the same horizontal plane as V6.
• V9 – Left paraspinal region, in the same horizontal plane as V6.

Front 38

Lead placement

Back 38

Front 39

Right Ventricular MI

Back 39

In setting of inferior MI:

• ST elevation in V1 - the only standard ECG lead that looks directly at the right ventricle.
• ST elevation in lead III > lead II – because lead III is more “rightward facing” than lead II and hence more sensitive to the injury current produced by the right ventricle.

Other signs:

• If the magnitude of ST elevation in V1 exceeds the magnitude of ST elevation in V2.
• If the ST segment in V1 is isoelectric and the ST segment in V2 is markedly depressed.
• NB. The combination of ST elevation in V1 and ST depression in V2 is highly specific for right ventricular MI.

Confirmed by right sided leads with STE

Front 40

When to consider additional ECG leadings:

Back 40

(1) ST segment changes (depression or
elevation) in leads V1 to V3, either in an isolated lead or in more than one

(2) equivocal ST segment elevation in the inferior (II, III, aVF) or lateral (I, aVL) limb leads or both;

(3) all inferior STEMI

(4) hypotension in the setting of ACS.

Front 41

Sensitivity and specificity of single ECG for acute MI

Back 41

Sensitivity: 60%

Specificity: 90%

Front 42

Sgarbossa Criteria

Back 42

• Concordant ST elevation > 1mm in leads with a positive QRS complex (score 5)
• Concordant ST depression > 1 mm in V1-V3 (score 3)
• Excessively discordant ST elevation > 5 mm in leads with a negative QRS complex (score 2). This criterium is sensitive, but not specific for ischemia in LBBB. It is however associated with a worse prognosis, when present in LBBB during ischemia.

Front 43

MATU TACHYCARDIA ALGORITHIM

Back 43

Front 44

Approach to bradycardia

Back 44

(1) What are the atria doing?

(2) What are the ventricles doing?

(3) What is the relationship between the atria and ventricles?

Front 45

Diagnostic criteria WPW

Back 45

• A short PR interval (<0.12 second)

• QRS duration greater than 0.10 second
• A slurred upstroke to the QRS complex, referred to as a
delta wave

Front 46

Normal P wave axis

Back 46

Upright in I, II, aVf

Front 47

Pediatric ECG difference

Back 47

Higher normal resting HR

Rightward axis

Short PR interval and QRS

Longer QT for 1st 6 months of life

Juvenille T wave pattern

Front 48

ECG Criteria for LVH

Back 48

(1) Deepest S in V1/V2 + Deepest R in V5/V6 >35

(2) Any precordia >45

(3) AVL > 11

(4) I > 12

(5) AVF > 20