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10

Index

Subject Page Introduction 1

Principles of ECG 5

ECG graph 12

Comment on ECG 13 Rhythm 13 Rate 14 Axis 15 P wave 18 P-R interval 20 QRS complex 22 S-T segment 25 T wave 29 Q-T interval 29 U wave 29

Abnormal ECG 30 Chamber enlargement 30

Bundle branch block 33

Coronary Ischemia 35

Heart block 37

Others 40

How to interpret an ECG 41

How to diagnose an ECG 42

Innovation Simple ECG

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Introduction The electrocardiogram (ECG or EKG) is a special graph that represents the electrical

activity of the heart from one instant to the next. Thus, the ECG provides a time-voltage chart of the heartbeat. For many patients, this test is a key component of clinical diagnosis and management in both inpatient and outpatient settings. The device used to obtain and display the conventional ECG is called the electrocardiograph, or ECG machine. It records cardiac electrical currents (voltages or potentials) by means of conductive electrodes selectively positioned on the surface of the body.

This book is devoted to explaining the basis of the normal ECG and then examining the major conditions that cause abnormal depolarization (P and QRS) and repolarization (ST-T andU) patterns.

Why is the ECG so clinically useful ? The ECG is one of the most versatile and inexpensive of clinical tests. Its utility derives

from careful clinical and experimental studies over more than a century showing the following:

It is the essential initial clinical test for diagnosing dangerous cardiac electrical disturbances related to conduction abnormalities in the AV junction and bundle branch system and to brady- and tachyarrhythmias.

It often provides immediately available information about clinically important mechanical and metabolic problems, not just about primary abnormalities of electrical function. Examples include myocardial ischemia/infarction, electrolyte disorders, and drug toxicity, as well as hypertrophy and other types of chamber overload.

It may provide clues that allow you to forecast preventable catastrophies. A good example is a very long QT(U) pattern preceding sudden cardiac arrest due to torsades de pointes.

Physiological anatomy of the heart : The heart is a hollow muscular pump situated in the left side of the thoracic cavity partly behind the sternum, consisting of 4 chambers : 2 atria and 2 ventricles. The heart is covered externally by epicardium ( which is the visceral layer of the pericardial sac). The inside cavity of the heart lined by endothelial layer called the endocardium. An intermediate muscular layer lying in between the epicardium & endocardium known as the myocardium.


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Physiology of Cardiac Muscle : The heart is composed of three major types of cardiac muscle:

atrial muscle, ventricular muscle, and specialized excitatory and conductive muscle fibers. The atrial and ventricular types of muscle contract in much the same way as skeletal

muscle, except that the duration of contraction is much longer. Conversely, the specialized excitatory and conductive fibers contract only feebly because they contain few contractile fibrils; instead, they exhibit either automatic rhythmical electrical discharge in the form of action potentials or conduction of the action potentials through the heart, providing an excitatory system that controls the rhythmical beating of the heart.

The cardiac muscle has certain special properties which are :

1. Rhythmicity: ability of the heart to beat regularly at constant rate. 2. Contractility: ability of the heart to contract and push blood into circulation.

3. Excitability: ability of the cardiac muscle to respond to an adequate stimulus contraction.

4. Conductivity: ability of the cardiac muscle to conduct excitation wave from one part of the heart to another.

In EKG study we are concerned with study of Rhythmicity and conductivity of the cardiac muscle.

we will review a few simple principles of the heart’s electrical properties. The central

function of the heart is to contract rhythmically and pump blood to the lungs for oxygenation and then to pump this oxygen-enriched blood into the general (systemic) circulation. The signal for cardiac contraction is the spread of electrical currents through the heart muscle. These currents are produced both by pacemaker cells and specialized conduction tissue within the heart and by the working heart muscle itself.

Pacemaker cells are like tiny clocks (technically called oscillators) that repetitively generate electrical stimuli. The other heart cells, both specialized conduction tissue and working heart muscle, are like cables that transmit these electrical signals.

Electrical Activation of the Heart : In simplest terms, therefore, the heart can

be thought of as an electrically timed pump. The electrical “wiring” is outlined in Figure.

Normally, the signal for heartbeat initiation starts in the sinus or sinoatrial (SA) node. This node is located in the right atrium near the opening of the superior vena cava.


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The SA node is a small collection of specialized cells capable of automatically generating an electrical stimulus (spark-like signal) and functions as the normal pacemaker of the heart. From the sinus node, this stimulus spreads first through the right atrium and then into the left atrium. Electrical stimulation of the right and left atria signals the atria to contract and pump blood simultaneously through the tricuspid and mitral valves into the right and left ventricles.

The electrical stimulus then reaches specialized conduction tissues in the atrioventricular (AV) junction. The AV junction, which acts as an electrical “relay” connecting the atria and ventricles, is located at the base of the interatrial septum and extends into the interventricular septum. The upper (proximal) part of the AV junction is the AV node. (In some texts, the terms AV node and AV junction are used synonymously.) The lower (distal) part of the AV junction is called the bundle of His. The bundle of His then divides into two main branches: the right bundle branch, which distributes the stimulus to the right ventricle, and the left bundle branch, which distributes the stimulus to the left ventricle.

The electrical signal then spreads simultaneously down the left and right bundle branches into the ventricular myocardium (ventricular muscle) by way of specialized conducting cells called Purkinje fibers located in the subendocardial layer (inside rim) of the ventricles. From the final branches of the Purkinje fibers, the electrical signal spreads through myocardial muscle toward the epicardium (outer rim).

The His bundle, its branches, and their subdivisions are referred to collectively as His-Purkinje system. Normally, the AV node and His-Purkinje system form the only electrical connection between the atria and the ventricles (unless a bypass tract is present). Disruption of conduction over these structures will produce AV heart block.

Just as the spread of electrical stimuli through the atria leads to atrial contraction, so the spread of stimuli through the ventricles leads to ventricular contraction, with pumping of blood to the lungs and into the general circulation. The initiation of cardiac contraction by electrical stimulation is referred to as electromechanical coupling. A key part of this contractile mechanism is the release of calcium ions inside the atrial and ventricular heart muscle cells, which is triggered by the spread of electrical activation. This process links electrical and mechanical function.

The ECG is capable of recording only relatively large currents produced by the mass of working (pumping) heart muscle. The much smaller amplitude signals generated by the sinus node and AV node are invisible with clinical recordings.

Depolarization of the His bundle area can only be recorded from inside the heart during specialized cardiac electrophysiologic (EP) studies.

Heart has two types of action

Mechanical: Contraction &relaxation

Electrical: Depolarization & repolarization


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Blood supply of the heart through the coronary arteries

Anatomy of the coronary arteries

The left Coronary artery: It arises from the left sinus of Valsalva and

passes forwards & to the left in the atrioventricular groove for a short distance and then divides into two branches:

1. The left anterior descending artery: it passes downwards in the anterior interventricular groove to the apex of the heart & then turns backwards to anastomse with the posterior descending artery.

2. The circumflex artery: it continues its course in the left atrioventricular groove to anastomse with the right coronary. It gives several obtuse marginal branches.

The right Coronary artery: It arises from the (right sinus) of Valsalva and runs in the right atrioventricular groove to the posterior surface of the heart to anastomse with circumflex artery. In the back of the heart it gives the (posterior descending artery which runs downwards, in the posterior interventricular groove, to anastomose with the anterior descending artery.

Pattern of coronary supply

Balanced circulation: The left coronary artery supplies left atrium, left ventricle & anterior part of the

interventricular septum. While the right coronary artery supplies right atrium, right ventricle & posterior part of

the interventricular septum.

Right dominance: The right coronary supplies also the posterior part of the left ventricle.

Left dominance: The left coronary supplies also the posterior part of the septum & the posterior wall of the

right ventricle.


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Principles of ECG ECG

Electrocardiogram

Electro

Cardio

Gramgraph

ECG

ECG relaxed

<< <<<<waves

Lead ECG

<<positive wave ECG

Lead

ECG << negative wave

ECG

Lead

ECG << biphasic wave

Positive negative

WaveECG thickness of the muscle

wave left ventricle wave right ventricle

thickness of muscle left ventricle right ventricle


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left ventricular hypertrophy wave lead

heart ECG

Atria Ventricles

ventricle

ventricle right ventricle left ventricle septum

ventricle

septum right ventricle left ventricle

septum

left bundle branchleft right

septum right bundle septum

waves septum

Lead ECG <<positive wave ECG

Lead ECG << negative wave ECG

left right

septum

chest lead V1

positive wave

thickness of muscle septum

wave

r wave

chest lead V6 negative wave


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thickness of muscle septum

wave

q wave

septum right ventricle

waves right ventricles

septum

chest lead V1

cavity bundle branch

endocardium

positive wave

thickness of muscle right ventricle

wave

r wave

chest lead V6 negative wave

thickness of muscle right ventricle

wave

q wave

right ventricle waves

ECG wave septum

small r wave in V1 septum right

ventricleq wave septum wave right

ventricleV6


left ventricle

waves left ventricle


chest lead V1


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cavity bundle branch endocardium

negative wave

thickness of muscle left ventricle

wave

S wave

chest lead V6 positive wave

thickness of muscle left ventricle

wave

R wave

chest leads

V1right ventricle

V1 S r wave

right ventricular pattern

V6left ventricle

V6

s wave

left ventricular pattern

Five waves

P QRS complex

T wave

P wave Atrial depolarization

QRS complex ventricular

depolarization T wave ventricular

repolarization


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P wave Atrial depolarization

P wave atrium

atrium P wave

Atrium P wave

atrium contraction ventricle Multiple P waves before QRS

atrium contraction absent P wave

P wave Atrium

QRS complex ventricular depolarization

ventricle

ventricle QRS

ventricle ventricular tachycardia

arrhythmia ventricle << QRS deformed

ventricle QRS

T wave

Ventricular repolarization

Atrial contractionatrial depolarization

ventricular depolarizationventricular contraction

ventricular repolarization ventricular relaxation

Atrial repolarization

which is small and masked by QRS complexQRS

QRS

A.V. node

ECG PR interval

PR interval A.V. nodal conduction

A.V. node

PR interval

PR interval A.V. nodal conduction

heart block A.V. nodal block


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ECG ECG 12 leads

Limb leads Chest leads

Limb leads

Bipolar Unipolar

Bipolar limb leads : L1both upper limbs L2right upper limb and left lower limb L3left upper limb and left lower limb

unipolar limb leads

aVRaugmented voltage right arm aVLaugmented voltage left arm aVF augmented voltage left foot

Chest leadschest wall precordial leads

6 chest leads

V1, V2, V3, V4, V5, and V6

ECG

ECG

ECG

6 leads

chest leads

V1: Right 4th space adjacent to the sternum V2: Left 4th space adjacent to the sternum


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V3 Between V2 and V4 V4: Left 5th space mid clavicular line V5at same horizontal level of V4 but at anterior axillary line V6: at the same horizontal level of V4 but at mid axillary line

chest leads Dextrocardia

V3Ras V3 but on right side V4R: as V4 but on right side V5R: as V5 but on right side V6R: as V6 but on right side

section heart

Right ventricle V1 and V2

left ventricle V5 and V6

Septum V3 and V4

right ventricle ischemia << ischemia V1 and V2

left ventricle ischemia V5 and V6

topographism

Wall of the heart leads of ECG

Leads Wall

II - III - aVF Inferior

I - aVL High lateral wall

V1 - V2 Septal ( antro-septal)

V3 - V4 Strict anterior

V5 - V6 Low lateral

V1 - V3R V6R RV free wall

Louis Leads Atrial Activity

N.B. posterior wall potentials are recorded in the anterior leads as a mirror image for

waves provided to be drawn in the posterior leads because posterior leads are

technically difficult to be made.

topographism

Leads artery wall


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ECG Graph paper ECG

5 X 5

voltage

duration

duration

ECG

25 mm

0.04

0.04 X 50.20

1/5

5X 60300

25X 601500

Voltage

ECG 1 mV signal

10mm

Caliberation 1mV 2 big squares Standard

half caliberation

one big square waves

double caliberation

4 big squares


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Comment on ECG ECG

1. Rhythm 2. Rate 3. Axis 4. P wave 5. P-R interval 6. QRS complex 7. S-T segment 8. T wave 9. Q-T interval 10. U wave

1. Rhythm

Rhythm ECG

Sinus or not

Regular or irregular

sinus

P wave is followed by QRS complex QRS complex Q R S complex

S R Q

ventricular complex

P wave

regular

Numbers of big squares between each R-R interval are equalR-R interval <<

R-R interval

rhythm is irregular

rhythm irregular

marked irregularity Atrial fibrillation

occasional irregularity extra systole

rhythm long strip


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long strip lead 3

R-R interval

2. Rate normal rate

60 90 << beat per minute

100 << tachyarrhythmia

60 << bradycardia

rate

rhythm

regular rhythm << heart rate = 300 R-R interval

1500 R-R interval

rhythm << Irregular

rate

300R-R interval

300mean average

15

1051530

30/3 10

10

RR interval

9

3

9/33

rate 300 << 300/3100 beats per min.


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2

Lead 23

306

30

10

rate

heart rate

5X 10 50

1530

ECG rate rhythm

3. Axis

lead lead aVF

aVF

QRS


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QRS

Lead QRS << Positive

lead

QRS positive

normal

lead QRS << positive

lead aVF

QRS << Positive

Axis is normal

Axis is normal

Lead

QRS << negative

lead aVF

QRS << positive

QRS

QRS

right axis deviation

QRS

lead positive


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lead negative

left axis deviation

lead lead

aVF

Positive Normal

Lead positive

lead aVF Negative

left axis

deviation

Lead negative

lead aVF positive

right axis deviation

axis deviation

right axis deviation Left axis deviation

Normal axis deviation

normal axis deviation

Normal axis is not deviated

right and left axis deviation

Causes of right axis deviation Causes of left axis deviation

Children

Tall thin adults

Right ventricular hypertrophy

Chronic lung disease

Anterolateral myocardial infarction

Pulmonary embolus

Atrial septal defect

Ventricular septal defect

Q waves of inferior MI

Artificial cardiac pacing

Left ventricular hypertrophy

Hyperkalemia

Ostium primum ASD

Injection of contrast into left coronary artery

Note : pt. of left ventricular hypertrophy not usually has LAD


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4. P wave

Atrial depolarization

1st positive wave before complex

Lead II and V1

Less than (2.5 X 2.5 ) small squares Width (duration ) : = ˂ 2.5 small square ( ˂ 0.12 sec. ). Height (amplitude) : = ˂ 2.5 small square ( ˂ 2.5 mm).

P wave

Present

Absent

P wave

Normalless than 2.5 X 2.5 small squares Lead II and V1 Abnormal

P wave << abnormal <<

1 M shaped P mitral

P wave 2.5

left atrial strain left atrial enlargement

2 Peaked and high voltage PP pulmonale

P wave 2.5

right atrial strain

3 Pulmonale Mitral

P wave 2.5

4 Biphasic

positive negative P wave

Normal Mitral


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V1

V1

P wave biphasic

right atrium

left atrium

SA node activate

right atrium

activate Left atrium

SA node right

wave

right atrium

wave

Left atrium

P wave

biphasic Positive negative

Positive right atrial strain (enlargement)

negative left atrial strain ( enlargement)

Lead

P wave << absent

rhythm << irregular

AF

rhythm << regular

P wave

QRS

QRS

QRS << wide


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wide

QRS 3

3

3

Wide QRS

Ventricular tachycardia

Ventricular fibrillation

QRS << narrow

supra ventricular tachycardia

Nodal rhythm

rate

supra ventricular tachycardia <<

Nodal rhythm

Sawtooth appearance

atrial flutter

5. P-R interval

AV conduction (physiological delay)

Lead II

3-5 small squares (0.12 - 0.20 sec. )

PR

P QRS complex

P-R interval

Normal 3 - 5 small squares

Prolonged5 small squares


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Shortened3 small squares P-R interval << prolonged

1 P-R interval <<

just prolongation of P-R intervalFirst degree heart block

2 P-R interval <<

beat

progressive prolongation of P-R interval until dropped beatWenckebach phenomena

<<<<peace maker

peace maker

3 P-R interval << not fixed

atria ventricles

atrio-ventricular dissociationatrium S.A. node ventricle

P-R interval variable P-R

P wave QRS complex

complete heart block


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P-R interval <<shortened

Wolff-Parkinson-White

delay impulse A.V. node

accessory pathway impulses atria ventricle

normal pathway P-R interval

3 small squares

QRS complex waves

complex <<QRS complex wide

Criteria Wolff-Parkinson-White

1 Short P-R interval 2 Wide QRS complex

3 Delta wave

Wolff-Parkinson-White

V1

right ventricular pattern type B

left ventricular pattern type A

6. QRS complex

Ventricular depolarization

complex P T

Right ventricle (V1,2) Left ventricle (V5,6)

Q wave << first negative wave in the complex R wave << first positive wave in the complex

S wave << the negative wave following R following R

Q wave

first negative wave in the complex


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one small square

R wave

pathological Q

Deep and wideECG

myocardial infarction

Q wave infraction

Non Q wave infarction

Q wave ( deep and wide )

V1,2 <<anterior infarction

V3,4 << septal infarction

V5,6 << Lateral infarction

V1,2,3,4<< antro-septal infarction

V1,2,3,4,5 << Extensive anterior infarction

pathological Q Normal ECG

lead of aVR<< the cavity of the heart

Normally aVR<< Q wave

pathological Q << dextrocardia pathological Q aVL

V1 r wave S wave pathological Q

pathological Q ( deep and wide ) V1

Lead aVR and V1

pathological Q


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infarction << V1V2anterior

V1

r wave is too small to be detected

pathological Q

R wave

first positive wave in complex only positive in the complex

voltage criteria

big squares

small squares 3 small squares wide complex RBBB or LBBB Vent. Tachycardia

S wave

first negative wave following R

S and R wave Chest leads

S V1 V5

R wave V1 V6

principles

r right ventricle V1 R left ventricle V6

S in V2 is ˃ S in V1 S progress from V2 to V5 S usually absent in V6

Waves

capital and small

amplitudewave 5 mm

<<small

amplitude wave 5 mm

<< capital

capital << R, S Small << rs

Not every “QRS” contain “Q”,”R” & “S”, but it may be : Monophasic (R or QS)


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Biphasic (RS or QR) Triphasic (QRS or RSR’)

R wave low voltage high voltage

˂ 1 big square (low voltage) ˃ 5 big squares (high voltage )

Terminal heart failure

Cardiomyopathy

IHD

Obesity

Emphysema

Pericardial effusion

Ventricular hypertrophy

7. S-T segment


leads

S T

S-T segment

Iso-electric line Elevated Depressed

elevation depression iso-electric line

J point

J point

Point where QRS complex returns to iso-electric line.

Beginning of S-T segment.

Critical in measuring S-T elevation.

iso-electric line

P-R T-P line


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S-T elevation

ST segment elevation PR

Pericarditis Myocardial infarction Prinzmetal’s angina

Pericarditis

ST segement elevation

Leads

AnginaMyocardial infarction

some leads

angina myocardial infarction

Cardiac enzymesinfarction

timing

ECG S-T elevated


angina

S-T depression

ST segment depression

Digitalis

Hypokalemia

angina ischemia angina << clinical diagnosis

Myocardial infarction

Pericarditis

cardiac hypertrophy

bundle branch block

Digitalis

hypokalemia

pericarditis


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diffuse ST segment depression

Leads

digitalis

ST segment depression J point iso-electric line

sagging

hypokalemia

serum potassium

Pericarditis

clinically pain << stitchy

some leads



hypertrophy

bundle branch block

V1V2V3

Leads right ventricle


V1V2V3

right ventricular hypertrophy

strain pattern

right ventricular hypertrophy With strain patternsecondary changes

left ventricular enlargement

ST segment depression V4V5V6

right bundle branch block


left bundle branch block


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V1rSR’

Right bundle branch blockST segment

depressed

right bundle



V6


V4V5V6


secondary left ventricular hypertrophy

ventricular hypertrophy

bundle branch block



ischemia

leads hypertrophy

J point iso-electric line

digitalis toxicity <<J point iso-electric line

Pericarditis ECG changes

ECG cardiac muscle

pericarditis

very superficial myocarditis


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8. T wave (Never absent )


Less than 6 small squares

1/3 R wave

Uprightpositive

Invertednegative wave

T wave ( positive )

Normal HyperacuteT

hyperkalemia

ECG

T wave inverted

normal T wave inversion

Upright dynamic T

9. Q-T interval QRS complex T wave

0.44 sec 11 small square

Long Q-T interval

Drugs ( many antiarrhythmics, tricyclics & phenothiazines) Electrolyte abnormalities (K+, Ca++, Mg++) CNS disease (especially subarachnoid hemorrhage, stroke, trauma) Hereditary LQT

10. U wave


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These waves, usually most apparent in chest leads V2-V4, may be a sign of hypokalemia or drug effect or toxicity (e.g., amiodarone, dofetilide, quinidine, or sotalol).

Abnormal ECG

1 Chamber enlargement 2 Bundle branch block (BBB) 3 Coronary ischemia (MI & ischemia) 4 Heart block 5 Others

1. Chamber enlargement

Atrial enlargement Ventricular enlargement

atrial enlargement

Right atrial enlargement Left atrial enlargement

ventricular enlargement

Right ventricular enlargement Left ventricular enlargement

atrial enlargement

P wave atrium

atrium P wave

P wave Lead II and V1 P wave << peaked

<<

P pulmonal

right atrial enlargement

P wave << broad << P mitral

Left atrial enlargement


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Normal Mitral

V1

P wave biphasic

right atrium

left atrium

SA node activate

right atrium

activate Left atrium

SA node right

wave

right atrium

wave

Left atrium

P wave

biphasic Positive negative

Positive right atrial strain (enlargement)

negative left atrial strain ( enlargement)

Lead

Ventricular enlargement

QRS ventricular depolarization

ventricle QRS complex abnormalities

QRS V1,2,5,6

V1,2

S wave r wave V5,6

R wave s wave

V1,2 S wave r wave

S wave <<deep Normal


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V5,6 R wave s wave

R wave << normal

exaggeration of normal

voltage criteria exaggeration of normal

S 5 big squares V1 V2 R 5 big squares V5V6 S + R 7 big squares

left ventricle


left ventricle

hypertrophy

Strain ischemia

ventricle

strain ischemia

strain ischemia

depressed ST segment

inverted T wave

Left ventricle

V5 and V6

Strain ischemia V5 and V6

Left ventricle

right ventricle

R wave s wave V1,2

Normal

S wave r wave V5,6


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Normal

I can diagnose right ventricle from V1

V2 V5 V6

Right ventricle

right ventricle

Strain ischemia

strain ischemia depressed ST segment

Inverted T wave

V1 V2

Strain ischemia right ventricle V1 and V2 left ventricle V5 and V6

Bi ventricular hypertrophy

strain ischemia V1 and V2 V5 and V6

bi ventricular hypertrophy ECG

S R


reversal of normal

V1 exaggeration of normal

V2 reversal of normal

2. Bundle Branch Block (BBB)

Right bundle branch block Left bundle branch block

bundle branch block

QRS M

RSR'

V1 V2 right bundle branch block

V5 V6 left bundle branch block


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right and left bundle branch block

RSR' pattern V1 V2 Right

RSR' V5 V6 left

QRS

QRS

shape

direction

voltage

QRS

shape direction voltage

shape

M shaped

bundle branch block

direction

direction

V1 and V2

S R

V5 V6

R S

reversal of normal

direction


shape << Normal

direction << Normal

voltage

voltage


Left ventricular hypertrophy

QRS


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shape

direction

voltage

abnormality shape

bundle branch block

direction voltage

ventricle

direction

Normal shape

Normal shape

direction

direction

reversal of normal

voltage

3. Coronary Ischemia ( MI & ischemia )


central area of necrosis surrounded by an area of tissue damage surrounded by an ischemic pattern

area of necrosis << pathological Q

tissue damage << elevated ST segment

ischemia << inverted T

wave or peaked T

infarction

necrosis

pathological Q

Once


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pathological Q

Old myocardial infarction

pathological Q

Myocardial infarction

finger print of MI is the pathological Q

Infarction

elevated ST segment

Elevated ST segment << recent MI

old MI recent MI

topographism

recent MI anterior wall

Inferior wall Lateral wall

old MI

topographism

MI topographism

pathological Q Elevated ST segment

Old Recent

Infarction

artery

Infarction

necrosis

elevated ST segmentrecent


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ECG

pathological Q

ST

elevated ST segment pathological Q

Once elevated ST segment

recent MI Q Q

<<Old inferior MI recent anterior MI

leads Old inferior

leads recent anterior

Lead

artery

Ischemia

Depressed ST segmenttopographism

Depressed

Inferior anterior lateral ischemia

topographism

4. Heart Block

ECG

hear block Mainly

A.V. nodal block

A.V. node

first degree heart block

second degree heart block

Atrium ventricle

third degree heart block

heart block

first degree heart block second degree heart block third degree heart block


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A.V. node

Just prolonged PR intervalJust prolonged PR interval


sinus brady cardia

sinus bradycardia S.A. node

P QRS T

sinus brady cardia first degree heart block

:

definition of first degree heart block

just prolonged PR interval

second degree heart blockA.V. node

A.V. node

Mobitz one

Mobitz two Mobitz one

progressive prolongation of PR interval until dropped QRS

A.V. node

Long strip

RR interval

Mobitz one

irregular


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dropped beat

Long strip

Mobitz Two

A.V. node

atrium

system

Mobitz Two

regular drop of QRSP P QRS T P P QRS T

P P QRS

A.V. node

second degree heart block

IrregularMobitz one

RegularMobitz Two

third degree heart blockA.V. node

Atrium S.A. node

ventricle idioventricular rhythm

ectopic focus

atrium


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P wave

QRS

ventricle

QRS ventricle

bizarre shaped

deformedA.V. node

narrow normal

QRS P P wave


A.V. dissociationatrio ventricular dissociation

atrium ventricle

P QRS

QRS

deformed

Bizarre shaped

All type of heart block are regular except<<.Mobitz one All types of heart block with normal QRS complex except<<. third degree heart block

regular Mobitz one

normal QRS Third degree complete heart block

5. Others ECG as a Clue to Acute Life-Threatening Conditions without primary Heart or Lung

Disease

Cerebrovascular accident (especially intracranial bleed)

Drug toxicity Tricyclic antidepressant overdose, digitalis excess, etc.

Electrolyte disorders Hypokalemia Hyperkalemia Hypocalcemia Hypercalcemia

Endocrine disorders


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Hypothyroidism Hyperthyroidism

Hypothermia

How to interpret an ECG ECG

Relax and take a deep breath

1 Rhythm

Sinus or not

Regular or not

2 Rate rhythm <<regular << 300R-R interval rhythm << Irregular <<R waves 3010

3 Axis Lead Positive lead aVF positive << Normal axis

lead positive lead aVF negative << left axis deviation

lead negative lead aVFpositive<< right axis deviation

4 P wave2.5 2.5

2.5 peaked <<right atrial strain 2.5 m shaped << left atrial strain

5 P-R interval35 P wave complex

6 QRS complex

Q wave << first negative wave in the complex R wave << first positive wave in the complex


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S wave << the negative wave following R following R

Q wave R wave

R wave

S wave R wave

7 ST segment

S T wave

MI

8 T wave absent

6R wave

diagnosis

diagnosis

How to diagnose an ECG rhythm

regular

irregular

irregular

irregular Atrial fibrillation Extra systole Mobitz one

atrial fibrillation

irregulartachy absent P

QRS Normal Absent P

atrial fibrillation P wave absent P wave


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some timefibrillation Absent P

AF rapid slow AF

Slow AF digitalis Beta blocker associated Heart block lone AF

AF slow AF irregular ECG

With absent P wave AF

Extra systole

refractory period stimlus

compensatory pause irregular

irregular

ventricular extra systole

Mobitz one

Progressive prolongation of PR interval until dropped QRS


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rhythm

regular << rate regular

Tachycardia bradycarida

normo cardia tachy cardia

Regular tachycardia Sinus tachycardia Ventricular tachycardia Supra ventricular tachycardia Atrial flutter

Sinus Tachycardia

Sinus tachy cardia

S.A. node

Peace maker of the heart

ECG

P followed by QRS T

P QRS T

Ventricular tachycardia

Ventricular tachycardia Arrhythmia ventricle

ventricle

QRS


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deformed QRS P T

QRS wide

Supra ventricular tachycardia

supra ventricular

tachycardia supra ventricualr

atrium

A.V. node

atrium P

deformed

A.V. node P

Inverted ) P (

P

P wave Inverted

A.V. node

P absent

Masked by QRS

supra ventricular tachy cardia

deformed PInverted P absent

P P


Atrial flutter Atrial flutter

atrium


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A.V. node

reduction

Atrial beat in mathematical fashion

atrium

specific Atrial flutter

Atrial flutter atrial fibrillation

atrial flutter regular

atrial fibrillation regular

regular long striprate tachycardia

QRS

deformed

Narrow normal

deformed

ventricular tachycardia

Narrow normal

P

P wave

single

multiple

single sinus tachycardia

P wave QRS T

multiple P

Atrial flutter


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Regular bradycardia

Sinus bradycardia first degree heart block Mobitz two third degree heart block Nodal rhythm

Sinus bradycardia regular bradycardia

sinus bradycardia

First degree heart block


Just prolonged PR interval


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Mobitz two

Mobitz two

regular drop of QRS complex

Third degree heart block


deformed QRS

AV dissociation

Nodal rhythm nodal rhythm

A.V. node peace maker

A.V. node peace maker

P

inverted


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QRS absent

regular bradycardia

QRS

deformed

Narrow normal

deformed third degree heart block Narrow normal

P wave P wave

single

Multiple

single sinus bradycardia first degree heart block


just prolonged PR interval

P wave multiple

Mobitz two

Mobitz two Atrial flutter

Mobitz two bradycardia

atrial flutter tachycardia

Noda rhythm

diagnostic approach long strip

rhythm rate QRS

P

segmented

P

QRS


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ST segment

Long strip

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