1. Electrocardiogram Interpretation: A Brief Overview
Wissam Alajaji, MD

2. Basic principles for ECG interpretation Normal ECG
Objectives:
Basic principles for ECG interpretation
Normal ECG
Abnormal ECG examples
13 slides
Know that This presentation will not cover “ECG dilemmas”
Should you code Q wave in V1, V2 or only when it involves all V1, V2, V3.”
A: only when V3 is involved
“in LBBB should you code acute MI?”
A: No
Wissam Alajaji, Electrocardiogram Interpretation: A Brief Overview, July-21, 2015.

3. Wissam Alajaji, Electrocardiogram Interpretation: A Brief Overview, July-21, 2015.

4. Basic principles for ECG interpretation
Before you look at the ECG:
Indication
- 20 YO man with syncope
- 50 YO man with acute chest pain
- 65 YO woman with HTN and chronic SOB
- 70 YO man with ESRD medications include digoxin, coming with altered level of consciousness
- Muscle thickness, QT, arrhythmia
- Chamber size and its complications
- ischemia and its complications
- electrolytes, drug toxicity
Wissam Alajaji, Electrocardiogram Interpretation: A Brief Overview, July-21, 2015.

5. Basic principles for ECG interpretation
Screen the ECG for quality:
Verify patients name, MRN, and date
Make sure that voltage is 10 mm/mv and calibrated
Screen for quality, correct lead placement, noise
Wissam Alajaji, Electrocardiogram Interpretation: A Brief Overview, July-21, 2015.

6. Wissam Alajaji, Electrocardiogram Interpretation: A Brief Overview, July-21, 2015.

7. Nothing is Random in Life
Na, TCA
Nothing is Random in Life
K Disturbance
Wissam Alajaji, Electrocardiogram Interpretation: A Brief Overview, July-21, 2015.
Ca Disturbance, Digoxin

8. Basic principles for ECG interpretation
Know how to calculate the HR, PR, QRS, and QT
Know what is a normal sinus morphology and identify abnormal
Know what is normal axis, normal voltage, normal vs pathologic Q, juvenile patterns, normal variants
Wissam Alajaji, Electrocardiogram Interpretation: A Brief Overview, July-21, 2015.

9. Nomenclature Waves -P wave -T wave -U wave Complex -QRS Segments
-PR segment
-ST segment
Intervals
-PR interval
-QT interval
Point
-J point
1 “little box” = 0.04 seconds (or 40 msec)
1 “big box” = 0.2 seconds (or 200 msec)
5 “little boxes” = 1 “big box”
5 “big boxes” = 1 second
Wissam Alajaji, Electrocardiogram Interpretation: A Brief Overview, July-21, 2015.

10. Step 1: Step 2: Locate RR interval: HR Rhythm & its origin
Can be difficult and complex
Most common mistake made by computer interpretation

11. For Boards Usually, your indication is your guide
Expected not to miss a serious/deadly finding/diagnosis
ST elevation
Hyperkalemia
Drug toxicity
Major pathology: heart block, arrhythmia, HCM……………………..
Usually, your indication is your guide
Do not worry about controversial or minor findings
Wissam Alajaji, Electrocardiogram Interpretation: A Brief Overview, July-21, 2015.

12. ECG Coding Sheet:
Wissam Alajaji, Electrocardiogram Interpretation: A Brief Overview, July-21, 2015.

13. Wissam Alajaji, Electrocardiogram Interpretation: A Brief Overview, July-21, 2015.

14. Inverted lead I in absence of Dextrocardia
Abnormally, normal avR
Unexpectedly "normal"
Inverted lead I in absence of Dextrocardia
Wissam Alajaji, Electrocardiogram Interpretation: A Brief Overview, July-21, 2015.

15. Rhythm
Wissam Alajaji, Electrocardiogram Interpretation: A Brief Overview, July-21, 2015.

16. So Far:
You learned to ask about/present the indication before interpretation
Scan for quality and lead placement
Know the various electrical waves/intervals and what is normal ECG
Wissam Alajaji, Electrocardiogram Interpretation: A Brief Overview, July-21, 2015.

17. Chamber Abnormality
Wissam Alajaji, Electrocardiogram Interpretation: A Brief Overview, July-21, 2015.

18. 24 year old man with syncope
Wissam Alajaji, Electrocardiogram Interpretation: A Brief Overview, July-21, 2015.

19. 45 year old man with HTN
Wissam Alajaji, Electrocardiogram Interpretation: A Brief Overview, July-21, 2015.

20. LVH Criteria: The Cornell criteria: Sokolow:
R wave in aVL + S wave in V3 > 28 mm in males and > 20 mm in females of the voltage criteria.
Therefore, the best policy is know most or all of the
Sokolow:
S in V1 or 2+ R in V5 or V6 > 35 mV
R avL > 11 mV
ST and/or T wave abnormalities, “strain” pattern
Wissam Alajaji, Electrocardiogram Interpretation: A Brief Overview, July-21, 2015.

21. Wissam Alajaji, Electrocardiogram Interpretation: A Brief Overview, July-21, 2015.

22. 37 Right axis deviation (> +100 msec)
Codes:
07 Sinus rhythm
37 Right axis deviation (> +100 msec)
41 Right ventricular hypertrophy
43 RBBB, complete
67 ST and/or T wave abnormalities secondary to hypertrophy
Wissam Alajaji, Electrocardiogram Interpretation: A Brief Overview, July-21, 2015.

23. Chest pain/SOB
Wissam Alajaji, Electrocardiogram Interpretation: A Brief Overview, July-21, 2015.

24. Wissam Alajaji, Electrocardiogram Interpretation: A Brief Overview, July-21, 2015.

25. 46 Left posterior fascicular block
Codes:
10 Sinus tachycardia
43 RBBB, complete
46 Left posterior fascicular block
53 Anterior or anteroseptal Q wave MI (age recent or acute)
57 Inferior Q wave MI (age recent or acute)
65 ST and/or T wave abnormalities suggesting myocardial injury
Wissam Alajaji, Electrocardiogram Interpretation: A Brief Overview, July-21, 2015.

26. Q1
Significant ST segment elevation consistent with myocardial injury or infarction is defined by:
≥ 1 mm STE in leads V1, V2, or V3
≥ 2 mm STE in leads V1, V2, or V3
≥ 2 in other leads
≥ 1 in other leads
Wissam Alajaji, Electrocardiogram Interpretation: A Brief Overview, July-21, 2015.

27. Q1
Significant ST segment elevation consistent with myocardial injury or infarction is defined by:
≥ 1 mm STE in leads V1, V2, or V3
≥ 2 mm STE in leads V1, V2, or V3
≥ 2 in other leads
≥ 1 in other leads
Wissam Alajaji, Electrocardiogram Interpretation: A Brief Overview, July-21, 2015.

28. Q2
Repolarization abnormality that suggest Acute or recent Myocardial infarction include:
Peaked T waves followed by T wave inversion
ST elevation followed by peaked T waves
Deeply inverted T waves
Dominant R wave and ST depression in V1-V3
Wissam Alajaji, Electrocardiogram Interpretation: A Brief Overview, July-21, 2015.

29. Q2
Repolarization abnormality that suggest Acute or recent Myocardial infarction include:
Peaked T waves followed by T wave inversion
ST elevation followed by peaked T waves
Deeply inverted T waves
Dominant R wave and ST depression in V1-V3
Wissam Alajaji, Electrocardiogram Interpretation: A Brief Overview, July-21, 2015.

30. Q3
Which parameter obtained on initial ECG independently predict 30 day all- cause mortality in acute myocardial infarction:
Sinus tachycardia
Sum of absolute ST segment deviation elevation and or depression
QRS duration > 100 msec
Rightward axis deviation
Wissam Alajaji, Electrocardiogram Interpretation: A Brief Overview, July-21, 2015.

31. Q3
Which parameter obtained on initial ECG independently predict 30 day all- cause mortality in acute myocardial infarction:
Sinus tachycardia
Sum of absolute ST segment deviation elevation and or depression
QRS duration > 100 msec
Rightward axis deviation
Hathaway WR, et al. JAMA 1996, 273:
Wissam Alajaji, Electrocardiogram Interpretation: A Brief Overview, July-21, 2015.

32. Wissam Alajaji, Electrocardiogram Interpretation: A Brief Overview, July-21, 2015.

33. Wissam Alajaji, Electrocardiogram Interpretation: A Brief Overview, July-21, 2015.

34. Wissam Alajaji, Electrocardiogram Interpretation: A Brief Overview, July-21, 2015.

35. 06 Left atrial abnormality/enlargement 10 Sinus tachycardia
Codes:
06 Left atrial abnormality/enlargement
10 Sinus tachycardia
36 Left axis deviation (> –30o)
47 LBBB, complete
Wissam Alajaji, Electrocardiogram Interpretation: A Brief Overview, July-21, 2015.

36. Q1
A QRS duration ≥ seconds is necessary for the diagnosis of complete LBBB:
0.10
0.11
0.12
0.13
Wissam Alajaji, Electrocardiogram Interpretation: A Brief Overview, July-21, 2015.

37. Q1
A QRS duration ≥ seconds is necessary for the diagnosis of complete LBBB:
0.10
0.11
0.12
0.13
When LBBB morphology is present and the QRS duration measures > 0.10 seconds but < 0.12 seconds, incomplete LBBB should be coded.
Wissam Alajaji, Electrocardiogram Interpretation: A Brief Overview, July-21, 2015.

38. LBBB is commonly seen in normal hearts:Q2
LBBB is commonly seen in normal hearts:
True
False
Wissam Alajaji, Electrocardiogram Interpretation: A Brief Overview, July-21, 2015.

39. LBBB is commonly seen in normal hearts:Q2
LBBB is commonly seen in normal hearts:
True
False
Never normal finding
LBBB often occurs in various forms of organic heart disease, including ischemic and non-ischemic cardiomyopathy, valvular heart disease, LVH, and congenital heart disease. It is rarely seen in normal hearts
Should not call it STEMI
Should not call LVH: 80% patients with LBBB have abnormally increased LV mass
Wissam Alajaji, Electrocardiogram Interpretation: A Brief Overview, July-21, 2015.

40. Q3
Non-voltage related changes often associated with left ventricular hypertrophy include all the following except:
Left atrial enlargement/abnormality
Left axis deviation
Intraventricular conduction disturbance
Prominent U waves
Sinus arrhythmia

41. Q3
Non-voltage related changes often associated with left ventricular hypertrophy include all the following except:
Left atrial enlargement/abnormality
Left axis deviation
Intraventricular conduction disturbance
Prominent U waves
Sinus arrhythmia
Non-voltage ECG changes in LVH
LA abnormality/enlargement, left axis, IVCD, QRS prolongation, abnormal Q waves in leads III and aVF, prominent U waves, and repolarization abnormalities.
Sinus arrhythmia (longest and shortest PP intervals vary by > 0.16 seconds or 10%) is a common finding on normal ECG’s that tends to occur in younger and healthier individuals and is not associated with LVH

42. LBBB interferes with the ECG diagnosis of:Q4
LBBB interferes with the ECG diagnosis of:
QRS axis
Left ventricular hypertrophy
Right ventricular hypertrophy
Acute MI

43. LBBB interferes with the ECG diagnosis of:Q4
LBBB interferes with the ECG diagnosis of:
QRS axis
Left ventricular hypertrophy
Right ventricular hypertrophy
Acute MI
Formal diagnosis of LVH should not be made in the setting LBBB
Echocardiographic and pathological studies show that ~ 80% patients with LBBB have abnormally increased LV mass

44. Bradycardia:
A very big book in ECG
Just on fun example

45. Wissam Alajaji, Electrocardiogram Interpretation: A Brief Overview, July-21, 2015.

46. 13 Atrial premature complexes
Codes:
07 Sinus rhythm
13 Atrial premature complexes
Wissam Alajaji, Electrocardiogram Interpretation: A Brief Overview, July-21, 2015.

47. Tachycardia:

48. Wissam Alajaji, Electrocardiogram Interpretation: A Brief Overview, July-21, 2015.

49. Codes: Sinus tachycardia Paroxysmal SVT
Wissam Alajaji, Electrocardiogram Interpretation: A Brief Overview, July-21, 2015.

50. Killer
Wissam Alajaji, Electrocardiogram Interpretation: A Brief Overview, July-21, 2015.

51. 24 year old man with stressful life
Wissam Alajaji, Electrocardiogram Interpretation: A Brief Overview, July-21, 2015.

52. Electrolyte/Drug toxicity:
Wissam Alajaji, Electrocardiogram Interpretation: A Brief Overview, July-21, 2015.

53. 65 year old man ESRD on dialysis presented with acute confusion
Peaked T waves
Wissam Alajaji, Electrocardiogram Interpretation: A Brief Overview, July-21, 2015.

54. 17 year old female found by her room mate unconscious
Wissam Alajaji, Electrocardiogram Interpretation: A Brief Overview, July-21, 2015.