HOW TO READ ELECTROCARDIOGRAPHY

SYARIF HIDAYATULLAH STATE ISLAMIC UNIVERSITY (UIN), JAKARTA

Dr. Yasmin Tadjoedin, Sp.JP

ECG INTERPRETATION

1. RATE 2. RHYTHM 3. AXIS 4. HIPERTROPHIC SIGNS 5. MYOCARDIAL INFARCTION 6. ARRHYTHMIA

STEPS IN ECG READING :

• Rhytm• QRS Rate• QRS Axis• P wave• PR Interval• QRS Duration• QRS Morphology • ST Segmen Deviation• T wave morphology• U wave• Others (LVH,LV Strain,BBB, QT

interval)• ECG conclusion

NORMAL VALUES :

PR Interval 0,12’’ - 0,20’’

QRS Duration 0,04’’ - 0,12’’

Normal Axis - 300 - + 1100

1. RATENormal heart rate : 60 – 100 x/minutes• > 100 x/minutes : Sinus Tachycardia• < 60 x/minutes : Sinus Bradicardia

Determination heart rate (normal paper speed 25 mm/s):• 300

Count number of large square (bold boxes in one R – R’ interval)• 1500

Count number of small square in one R – R’ intervals• Number of QRS complex in 6 seconds, multiply by 10

2. RHYTHM

Normal cardiac rhythm : SINUS rhythm

Sinus rhythm characteristics :• Rate 60-100 bpm• Constant R – R interval• Negative P wave in aVR and positive di II• P wave is always followed by QRS complex

3. AXIS

4. HYPERTROPHIC SIGNS

LEAD II

LEAD V1

5. MYOCARDIAL INFARCTION

• Ischemia• Injury• Necrosis

ANTERIOR INFARCTION

INFERIOR INFARCTION

POSTEROLATERAL INFARCTION

ARRHYTHMIA

AV BLOCK

Complete heart block

COMPLETE LEFT BUNDLE BRANCH BLOCK (LBBB)

COMPLETE RIGHT BUNDLE BRANCH BLOCK (RBBB)

WHAT’S WRONG??Lead Error: V1 and V3 are Transposed!In this normal 12-lead ECG the V1 and V3 chest electrodes are interchanged. Experienced ECG interpreters should be able to spot this lead placement error.