Title: Electrocardiogram Interpretation: A Brief Overview
1Electrocardiogram Interpretation A Brief Overview
Wissam Alajaji, MD
2- 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.
3Wissam Alajaji, Electrocardiogram Interpretation
A Brief Overview, July-21, 2015.
4Basic 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.
5Basic 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.
6Wissam Alajaji, Electrocardiogram Interpretation
A Brief Overview, July-21, 2015.
7Na, TCA
Nothing is Random in Life
K Disturbance
Ca Disturbance, Digoxin
Wissam Alajaji, Electrocardiogram Interpretation
A Brief Overview, July-21, 2015.
8Basic 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.
9Nomenclature
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
- Locate RR interval HR
- Step 2
- Rhythm its origin
- Can be difficult and complex
- Most common mistake made by computer
interpretation
11For Boards
- 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.
12ECG Coding Sheet
Wissam Alajaji, Electrocardiogram Interpretation
A Brief Overview, July-21, 2015.
13Wissam Alajaji, Electrocardiogram Interpretation
A Brief Overview, July-21, 2015.
14Abnormally, normal avR
Unexpectedly "normal"
Inverted lead I in absence of Dextrocardia
Wissam Alajaji, Electrocardiogram Interpretation
A Brief Overview, July-21, 2015.
15Rhythm
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.
17Chamber Abnormality
Wissam Alajaji, Electrocardiogram Interpretation
A Brief Overview, July-21, 2015.
1824 year old man with syncope
Wissam Alajaji, Electrocardiogram Interpretation
A Brief Overview, July-21, 2015.
1945 year old man with HTN
Wissam Alajaji, Electrocardiogram Interpretation
A Brief Overview, July-21, 2015.
20LVH Criteria
- The Cornell criteria
- R wave in aVL S wave in V3 gt 28 mm in males and
gt 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 gt 35 mV
- R avL gt 11 mV
- ST and/or T wave abnormalities, strain pattern
Wissam Alajaji, Electrocardiogram Interpretation
A Brief Overview, July-21, 2015.
21Wissam Alajaji, Electrocardiogram Interpretation
A Brief Overview, July-21, 2015.
22Codes 07 Sinus rhythm 37 Right axis deviation (gt
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.
23Chest pain/SOB
Wissam Alajaji, Electrocardiogram Interpretation
A Brief Overview, July-21, 2015.
24Wissam Alajaji, Electrocardiogram Interpretation
A Brief Overview, July-21, 2015.
25Codes 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 gt 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 gt 100 msec
- Rightward axis deviation
Hathaway WR, et al. JAMA 1996, 273 387-391.
Wissam Alajaji, Electrocardiogram Interpretation
A Brief Overview, July-21, 2015.
32Wissam Alajaji, Electrocardiogram Interpretation
A Brief Overview, July-21, 2015.
33Wissam Alajaji, Electrocardiogram Interpretation
A Brief Overview, July-21, 2015.
34Wissam Alajaji, Electrocardiogram Interpretation
A Brief Overview, July-21, 2015.
35Codes 06 Left atrial abnormality/enlargement 10
Sinus tachycardia 36 Left axis deviation (gt
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 gt 0.10 seconds but lt 0.12
seconds, incomplete LBBB should be coded.
Wissam Alajaji, Electrocardiogram Interpretation
A Brief Overview, July-21, 2015.
38- Q2
- LBBB is commonly seen in normal hearts
- True
- False
Wissam Alajaji, Electrocardiogram Interpretation
A Brief Overview, July-21, 2015.
39- 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 gt 0.16 seconds or
10) is a common finding on normal ECGs that
tends to occur in younger and healthier
individuals and is not associated with LVH
42- Q4
- LBBB interferes with the ECG diagnosis of
- QRS axis
- Left ventricular hypertrophy
- Right ventricular hypertrophy
- Acute MI
43- 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
44Bradycardia
- A very big book in ECG
- Just on fun example
45Wissam Alajaji, Electrocardiogram Interpretation
A Brief Overview, July-21, 2015.
46Codes 07 Sinus rhythm 13 Atrial premature
complexes
Wissam Alajaji, Electrocardiogram Interpretation
A Brief Overview, July-21, 2015.
47Tachycardia
48Wissam Alajaji, Electrocardiogram Interpretation
A Brief Overview, July-21, 2015.
49Codes Sinus tachycardia Paroxysmal SVT
Wissam Alajaji, Electrocardiogram Interpretation
A Brief Overview, July-21, 2015.
50Killer
Wissam Alajaji, Electrocardiogram Interpretation
A Brief Overview, July-21, 2015.
5124 year old man with stressful life
Wissam Alajaji, Electrocardiogram Interpretation
A Brief Overview, July-21, 2015.
52Electrolyte/Drug toxicity
Wissam Alajaji, Electrocardiogram Interpretation
A Brief Overview, July-21, 2015.
5365 year old man ESRD on dialysis presented with
acute confusion
Peaked T waves
Wissam Alajaji, Electrocardiogram Interpretation
A Brief Overview, July-21, 2015.
5417 year old female found by her room mate
unconscious
Wissam Alajaji, Electrocardiogram Interpretation
A Brief Overview, July-21, 2015.