ECG

Resources

Steps

    1. Is the axis normal?

    2. Is the rhythm regular?

    3. What is the heart rate?

    4. Is there a P wave?

      1. If yes, what are its properties and location?

    5. Is it a sinus rhythm?

    6. What do you know about the PR interval?

    7. What does the QRS complex look like and what are its properties?

    8. Does the ST segment look alright?

    9. Is the T wave normal?

    10. Is the QT interval in the normal range? (Calculate QTc)

    11. Look from a distance.

    12. Any other abnormalities in waves, intervals or segments?

Calculation

    • QTc = QT / sqrt(RR)

Normal ranges

    • P wave

      • Length 1 - 3 mm = 0.04 - 0.12 s

      • Amplitude 2.5 mm = 0.25 mV max.

    • PQ segment

      • 1 - 3 mm = 0.04 - 0.12 s

    • PQ interval

      • 3 - 7 mm = 0.12 - 0.20 s

    • QRS complex

      • 1.5 - 3 mm = 0.06 - 0.12 s

    • ST segment

      • 0.5 - 3 mm = 0.02 - 0.12 s

    • T wave

      • Length 3 - 4 mm = 0.12 - 0.16 s

      • Amplitude

        • 5 mm in I, II, III

        • Up to 10 mm in pre-cordial

      • Positive in leads I, II, aVL, V4 - V6

    • QTc

      • 0.44 s max.

    • QT

      • 0.44 x sqrt(RR) max.