1 / 45

ECG interpretation

ECG interpretation. Dr Ally Duncan SpR In Anaesthesia & Clinical Fellow in Undergraduate Medical Education Manchester Royal Infirmary May 2012. Objectives. Justify the reasons for performing an ECG Develop a structured approach to interpreting an ECG Practice interpreting ECGs. The ECG.

laquinta-liz
Download Presentation

ECG interpretation

An Image/Link below is provided (as is) to download presentation Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author. Content is provided to you AS IS for your information and personal use only. Download presentation by click this link. While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server. During download, if you can't get a presentation, the file might be deleted by the publisher.

E N D

Presentation Transcript

  1. ECG interpretation Dr Ally Duncan SpR In Anaesthesia & Clinical Fellow in Undergraduate Medical Education Manchester Royal Infirmary May 2012

  2. Objectives • Justify the reasons for performing an ECG • Develop a structured approach to interpreting an ECG • Practice interpreting ECGs

  3. The ECG “The ECG (electrocardiogram) is a transthoracic interpretation of the electrical activity of the heart.”

  4. The ECG

  5. Why perform an ECG? • It’s part of the admission bundle • Indicated by the patient’s symptoms - symptoms of IHD/MI - symptoms associated with dysrhythmias • Indicated by the patient’s examination findings - cardiac murmur

  6. Quality of ECG? Rate Rhythm Axis P wave PR interval QRS duration QRS morphology Abnormal Q waves ST segment T wave QT interval ECG interpretation

  7. Quality of the ECG • Patient name • Date of the ECG • Is there any interference? • Is there electrical activity from all 12 leads? • Calibration: - speed = 25mm/second - height = 1cm/mV

  8. Calibration

  9. Calibration

  10. ECG interpretation • Quality of ECG? • Rate • Rhythm • Axis • P wave • PR interval • QRS duration • QRS morphology • Abnormal Q waves • ST segment • T wave • QT interval

  11. Rate • 300/number of big squares between R waves • Rate is either: - normal - bradycardic - tachycardic

  12. Rate

  13. Rhythm • Are there P waves? • Are they regular? • Does one precede every QRS complex? • Regular vs. irregular

  14. Axis

  15. Axis

  16. Axis Positive in I and II = NORMAL Positive in I and negative in II = LAD Negative in I and positive in II = RAD

  17. Axis

  18. ECG interpretation • Quality of ECG? • Rate • Rhythm • Axis • P wave • PR interval • QRS duration • QRS morphology • Abnormal Q waves • ST segment • T wave • QT interval

  19. P wave • Are there P waves present? • Bifid = P mitrale (LA hypertrophy) • Pointy = P pulmonale (RA hypertrophy)

  20. P mitrale

  21. P pulmonale

  22. PR interval • Start of P wave to start of QRS complex • Normal = 0.12 - 0.2 seconds (3-5 small squares) • Decreased = can indicate an accessory pathway • Increased = indicates AV block (1st/2nd/3rd)

  23. ECG interpretation • Quality of ECG? • Rate • Rhythm • Axis • P wave • PR interval • QRS duration • QRS morphology • Abnormal Q waves • ST segment • T wave • QT interval

  24. QRS complex • Normal = <0.12 seconds • >0.12 seconds = Bundle Branch Block

  25. QRS complex W I LL ia m = LBBB M a RR o w = RBBB

  26. QRS complex • Is there LVH? • Sum of the Q or S wave in V1 and the tallest R wave in V5 or V6 >35mm is suggestive of LVH

  27. Q waves • Q waves are allowed in V1, aVR & III • Pathological Q waves can indicate previous MI

  28. ECG interpretation • Quality of ECG? • Rate • Rhythm • Axis • P wave • PR interval • QRS duration • QRS morphology • Abnormal Q waves • ST segment • T wave • QT interval

  29. ST segment • ST depression - downsloping or horizontal = ABNORMAL • ST elevation - infarction - pericarditis (widespread)

  30. ST segment

  31. ST segment

  32. ST segment

  33. T wave • Small = hypokalaemia • Tall = hyperkalaemia • Inverted/biphasic = ischaemia/previous infarct

  34. T wave

  35. T wave

  36. T wave

  37. QT interval • Start of QRS to end of T wave • Needs to be corrected for HR • Normal QTc = < 400ms • Long QT can be genetic or iatrogenic

  38. QT interval

  39. ECG quiz

  40. ECG 1

  41. ECG 2

  42. ECG 3

  43. ECG 4

  44. Any questions?

  45. Summary • Discussed the indications for performing an ECG • Introduced an approach to interpreting ECGs • Discussed common ECG abnormalities

More Related