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o Clinical diagnosis :Clinical diagnosis : Patient’s historyPatient’s history

Physical examinationPhysical examination

o ECG : provide evidence to support a diagnosis, ECG : provide evidence to support a diagnosis, (some cases) patient management(some cases) patient management

o ECG as a toolECG as a tool

o Interpreting the ECG : pattern recognitionInterpreting the ECG : pattern recognition

CalibrationCalibration

The 12-Lead ECGThe 12-Lead ECG

P

Q

R

S

T

P = depolarization of atria

Q = depolarization ofinterventricular septum

R = depolarization of left ventricle

S = depolarization of basal regions of the heart

T = repolarization of ventricles

Cardiac cycle

P wave : the sequential activation (depolarization) of the right and left atria

PR interval: time interval from onset of atrial depolarization (P wave

QRS complex: right and left ventricular depolarization (normally the ventricles are activated simultaneously)

QRS duration: duration of ventricular muscle depolarization

PP interval: duration of atrial cycle (an indicator or atrial rate)

RR interval: duration of ventricular cardiac cycle (an indicator of ventricular rate

QT interval: duration of ventricular depolarization and repolarization

ECG NOMENCLATUREECG NOMENCLATURE

Times and SpeedsTimes and Speeds

ECG interpretation…?ECG interpretation…?

1. Calibration2. Rate and rhythm3. QRS axis4. P morphology5. PR interval6. QRS duration7. QRS morphology8. ST segment morphology9. T morphology10. U morphology11. Others: LVH, LV strain, BBB, QT interval12. Conclusion: normal/abnormal

Determining the Heart RateDetermining the Heart Rate

Rule of 300Rule of 300

10 Second Rule10 Second Rule

Rule of 300Rule of 300

Take the number of “big boxes” between Take the number of “big boxes” between neighboring QRS complexes, and divide this neighboring QRS complexes, and divide this into 300. The result will be approximately into 300. The result will be approximately equal to the rateequal to the rate

Although fast, this method only works for Although fast, this method only works for regular rhythms.regular rhythms.

What is the heart rate?What is the heart rate?

(300 / 6) = 50 bpm

www.uptodate.com


(300 / 1.5) = 200 bpm

10 Second Rule10 Second Rule

As most EKGs record 10 seconds of rhythm per As most EKGs record 10 seconds of rhythm per page, one can simply count the number of beats page, one can simply count the number of beats present on the EKG and multiply by 6 to get the present on the EKG and multiply by 6 to get the number of beats per 60 seconds.number of beats per 60 seconds.

This method works well for irregular rhythms.This method works well for irregular rhythms.


33 x 6 = 198 bpm

The Alan E. Lindsay ECG Learning Center ; http://medstat.med.utah.edu/kw/ecg/

The Cardiac AxisThe Cardiac Axis

Depolarization spreads zation spreads

through the heart in many through the heart in many

direction at oncedirection at once

QRS complex shows the QRS complex shows the

average direction in which average direction in which

the wave of depolarization the wave of depolarization

is spreading through the is spreading through the

ventriclesventricles

The Cardiac AxisThe Cardiac Axis

Quadrant Approach: Example 1Quadrant Approach: Example 1

Negative in I, positive in aVF RAD

The Alan E. Lindsay ECG Learning Center http://medstat.med.utah.edu/kw/ecg/

Quadrant Approach: Example 2Quadrant Approach: Example 2

Positive in I, negative in aVF Predominantly positive in II

Normal Axis (non-pathologic LAD)

The Alan E. Lindsay ECG Learning Center http://medstat.med.utah.edu/kw/ecg/

Equiphasic Approach: Example 1Equiphasic Approach: Example 1

Equiphasic in aVF Predominantly positive in I QRS axis ≈ 0°


Equiphasic Approach: Example 2Equiphasic Approach: Example 2

Equiphasic in II Predominantly negative in aVL QRS axis ≈ +150°


Aktivasi AtrialAktivasi Atrial

Gelombang P terekam segera sesudah Gelombang P terekam segera sesudah impuls meninggalkan SA node.impuls meninggalkan SA node.

SA node berada di atrium kanan, aktivasi SA node berada di atrium kanan, aktivasi atrium atrium dimulai dari kanan dimulai dari kanan dan diikuti dan diikuti segera sesudahnya oleh atrium kiri. segera sesudahnya oleh atrium kiri. Proses keduanya saling Proses keduanya saling tumpang tindihtumpang tindih, , aktivasi atrium kiri dimulai sebelum akhir aktivasi atrium kiri dimulai sebelum akhir dari aktivasi atrium kanan.dari aktivasi atrium kanan.

Aktivasi atrial pada lead IIAktivasi atrial pada lead II

Gelombang P di Gelombang P di Lead II:Lead II:

Amplitudo Amplitudo << 2,5 2,5 mm.mm.

LLebarnya ebarnya < < 0,11 0,11 detikdetik

Notched Duration Notched Duration < 0,045 detik< 0,045 detik

PR intervalPR interval

Including P wave until the beginning of Including P wave until the beginning of QRS complexQRS complex

Normal duration is 0.12-0.2 secondsNormal duration is 0.12-0.2 seconds

QRS complexQRS complex

Wave of ventricular depolarizationWave of ventricular depolarization 5-20 mm tall5-20 mm tall Duration 0.06-0.10 secondsDuration 0.06-0.10 seconds

THE SHAPE OF THE QRS COMPLEXTHE SHAPE OF THE QRS COMPLEX

The QRS Complex in the limb leadsThe QRS Complex in the limb leads

The The QRS Complex in the V leadsQRS Complex in the V leads

Determined by 2 things : Septum depolarization, from left to right Wall of Left ventricle >> right ventricle

ECG pattern

Transition point !

Interpret this ECG..Interpret this ECG..

ECG abnormalitiesECG abnormalities

HypertrophyHypertrophy

Ischemia/infarct Ischemia/infarct

ArrhythmiaArrhythmia

HypertrophyHypertrophy

Right atrial enlargementRight atrial enlargement Tall, peaked p waveTall, peaked p wave

Left atrial enlargementLeft atrial enlargement Widenig p wave, M-shape, notchedWidenig p wave, M-shape, notched Deep, negative component p wave in V1Deep, negative component p wave in V1

Ventricular HypertrophyVentricular Hypertrophy

LVH (sokolow, Lyon)LVH (sokolow, Lyon) S di V1 + R di V5 atau V6 > 35 mmS di V1 + R di V5 atau V6 > 35 mm R di V5 atau V6 > 26 mmR di V5 atau V6 > 26 mm R + S di lead precordial > 45 mmR + S di lead precordial > 45 mm

RVH RVH R/S di V1 > 1 atau R/S di V6 < 1R/S di V1 > 1 atau R/S di V6 < 1

R in V5 > 26 mm

R/S in V1 > 1 or R/S in V6 < 1

ST depresi dan perubahan gelombang T

• ST depresi dianggap bermakna bila > 1 mm di bawah garis dasar PT di titik J• Titik J didefinisikan sebagai akhir kompleks QRS dan permulaan segmen ST

Bentuk segmen ST :

• up-sloping ( tidak spesifik )• horizontal ( lebih spesifik untuk iskemia )• down-sloping ( paling terpercaya untuk iskemia )

Perubahan gelombang T pada iskemia kurang begitu spesifik Gelombang T hiperakut kadang2 merupakan satu-satunyaperubahan EKG yang terlihat

ST DEPRESSIONST DEPRESSION

HORIZONTAL

DOWN SLOOPING

UP SLOOPING

Myocardial InfarctionMyocardial Infarction

Evolution of MIEvolution of MI Hyperacute T wave changes - Hyperacute T wave changes -

increased T wave amplitude and increased T wave amplitude and width; may also see ST elevation width; may also see ST elevation

Marked ST elevation with hyperacute Marked ST elevation with hyperacute T wave changes (transmural injury)T wave changes (transmural injury)

Pathologic Q waves, less ST Pathologic Q waves, less ST elevation, terminal T wave inversion elevation, terminal T wave inversion (necrosis) (necrosis)

Pathologic Q waves, T wave inversion Pathologic Q waves, T wave inversion (necrosis and fibrosis)(necrosis and fibrosis)

Pathologic Q waves, upright T waves Pathologic Q waves, upright T waves (fibrosis) (fibrosis)

STEMI Non STEMI

Mid LAD occlusion after the first septal perforator (arrow)

ECG : large anterior MI

Occlusion of diagonalbranch ( arrow )

ST elevation in I and aVL

ECG demonstrates large anterior infarction

Proximal large RCA occlusion

ST elevation in leads II, III, aVF, V5, and V6

with precordial ST depression

Small inferior distal RCA occlusion

ECG changes in leads II, III, and aVF

Acute inferoposterior MIAcute inferoposterior MI

CONDUCTION AND ITS CONDUCTION AND ITS PROBLEMSPROBLEMS

Prolonged PR interval

First Degree Heart Block

Conduction Problems in the AV Node and Conduction Problems in the AV Node and HIS BundleHIS Bundle

First Degree Heart BlockFirst Degree Heart Block

Note : - One P wave per QRS complex

- PR interval 360 ms

CAD, acute rheumatic carditis, digoxin toxicity, electrolite imbalance

Second Degree Heart Block Type ISecond Degree Heart Block Type I

Progressive lengthening of PR interval One non-conducted beat Next conducted beat has a shorter PR interval than the

preceding conducted beat

Missing QRS Missing QRS

• PR interval of the conducted beats is constant

• One P wave is not followed by a QRS complex

Second Degree Heart Block Type IISecond Degree Heart Block Type II

Missing QRS

• Two P waves per QRS Complex• Normal and constant PR interval in the conducted beats

Third Degree Heart Block / Total AV BlockThird Degree Heart Block / Total AV Block

• Rhythm : Regular• Rate : 40 – 60 if block in His bundle; 30 – 40 if block involves bundle branches• P wave : Sinus P wave present but no relationship to QRS, can be found hidden in QRS comp and T waves• QRS : Normal if block in His bundle; wide if block involves bundle branches

P PPPPPP

QRS QRS QRS

Conduction Problems in the Right and Left Conduction Problems in the Right and Left Bundle Branches - Bundle Branch BlockBundle Branches - Bundle Branch Block

RBBBRBBB LBBBLBBB

Principles :• The septum is normally depolarized from left to right• The wall of left ventricle >> right ventricle• Excitation spreading towards a lead causes an upward

deflection within the ECG

Right Bundle Branch BlockRight Bundle Branch Block

Incomplete right bundle branch block

CompleteComplete QRS duration > 0.12 sQRS duration > 0.12 s rSR’ in lead V1-V2rSR’ in lead V1-V2 Slurred S wave in lead I, aVL, Slurred S wave in lead I, aVL,

V5-V6V5-V6 Down sloping of ST segment Down sloping of ST segment

and T wave inversion in lead and T wave inversion in lead V1-V2V1-V2

Normal initial QRSNormal initial QRS

IncompleteIncomplete rSR’ complex in lead V1rSR’ complex in lead V1 QRS duration of 0.12 s or lessQRS duration of 0.12 s or less R or S waves are not broad or R or S waves are not broad or

slurredslurred Normal QRS axisNormal QRS axis

Left Bundle Branch BlockLeft Bundle Branch Block

Left bundle branch block

HemiblocksHemiblocks

Left Anterior HemiblockLeft Anterior Hemiblock

CriteriaCriteria QRS duration < 0.12QRS duration < 0.12 Left axis deviation more than -45 degreesLeft axis deviation more than -45 degrees qR wave in leads I, aVLqR wave in leads I, aVL Small rS complex in leads II, III, aVFSmall rS complex in leads II, III, aVF

Left Posterior HemiblockLeft Posterior Hemiblock

CriteriaCriteria QRS duration < 0.12 sQRS duration < 0.12 s Right axis deviation > +110 degreesRight axis deviation > +110 degrees Small r wave and large S wave in leads I, aVLSmall r wave and large S wave in leads I, aVL Small q waves in inferior leadsSmall q waves in inferior leads No other explanation for RAD (ex. RVH, No other explanation for RAD (ex. RVH,

COPD, lateral myocardial infarction)COPD, lateral myocardial infarction)

Bifascicular BlockBifascicular Block

How to identify arrhythmias ?

QRS complex Regular / irregular ?

QRS complexNormal-looking QRS complex?

Wide / narrow ?

P wave ?

Relationship between P and QRS ?

NORMAL SINUS RHYTHM

PSVT :

-due to re-entry mechanism-narrow QRS complex-regular-retrograde atrial depolarization-P wave ?

Atrial Fibrillation :

-from multiple area of re-entry within atria-or from multiple ectopic foci-irregular, narrow QRS complex-very rapid atrial electrical activity (400-700 x/min).-no uniform atrial depolarization

Atrial Flutter :

-The result of a re-entry circuit within the atria-Irregular / regular QRS rate-Narrow QRS complex-Rapid P waves (300x/min), “sawtooth”

Junctional rhythm:

-AV junction can function as a pace maker (40-60 x/min).-due to the failure of sinus node to initiate time impulse or conduction problem.-normal-looking QRS.-retrograde P wave.-P wave may preceede, coincide with, or follow the QRS

VES

SR

SR SR SR SRSR SR

VES VES

Sinus rhythm with Multifocal VES

Sinus rhythm with VES couplet

Sinus Rhythm with VES, R on T

Ventricular Tachycardia

Torsade de Pointes

Ventricular Fibrillation

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