The ECG provides a window into the heart, lungs, electrolytes, body temperature and sometimes the brain. It is important to systematically interpret the ECG by examining features like the rate, rhythm, axes, QRS complex, ST segment, T waves and QTc interval. Interpreting ECGs helps identify conditions like myocardial ischemia, electrolyte imbalances and long QT syndrome. It is important to record the time and name on the ECG and order repeat ECGs as needed to monitor patients.

1. ECG 101

2. The eyes may be the window to the
soul
But the ECG is the window to the heart,
lungs, toxicology, electrolytes, body
temperature and sometimes even the
brain

3. Pattern recognition

5. An ECG is put under your nose
Immediately
Interpret
Time
Name stamp
Covers nurse/HCA’s arse
Makes you read it
We know who to educate if it’s wrong

6. Be systematic
One system

7. Patient’s name
Presenting complaint

8. ECG machine
RR interval big squares: 300, 150, 100, 75, 60, 50
total number of complexes across the page x 6
Rate

9. Rhythm

10. Same patient after
treatment for sepsis

11. Frontal axis

12. Why else do we care
about axis?
CQC

13. Incomplete trifascilar block
RBBB, LAD and 1˚HB
1 myocyte away from complete heart block
Don’t send this post syncope patient home

14. Then proceed through
the complexes

15. p waves

16. PR interval

18. QRS complex

19. QRS complex

20. QRS complex

21. Killer Qs
Pathological Qs
> 40 ms (1 mm) wide
> 2 mm deep
> 25% of depth of QRS complex
Seen in leads V1-3

22. ST segment

24. ST
segment
R

25. ST segment

26. ST
segment

27. Original Sgarbossa Criteria
Concordant ST-segment elevation ≥ 1 mm in any lead (5 points)
oncordant ST-segment depression ≥ 1 mm in lead V1 – V3 (3 poin
Discordant ST-segment elevation ≥ 5 mm in any lead (2 points)

28. ST segment

29. T waves

30. Repeat
ECGs
13 minutes later, pain free:

31. T waves

32. T waves

33. T waves

34. QTc
Long QT syndrome (genetic)
Drugs incl amiodarone, digoxin, macrolides,
antipsychotics, tricyclics, SSRIs, loratidine
Hypothermia
HyperCa
HypoK, hypoMag
Myocardial ischaemia
ICH
+ others
> 440ms in men or
> 460ms in women

35. Methodical read
Record your interpretation
Time
Name stamp
Further actions esp
repeat ECGs q10min x 3 for CP
eg Trodat Printy 4910
http://www.selfinkingstamps.co.nz/shop/trodat-4910-26x9mm/
$20 delivered

36. References and images
Most facts checked with and images obtained from
Life in The Fast Lane
http://lifeinthefastlane.com/