Brainscape's Knowledge GenomeTM

Browse over 1 million classes created by top students, professors, publishers, and experts.


See full index

Pediatric ECG > Peds ECG (McMaster Guide) > Flashcards

Peds ECG (McMaster Guide) Flashcards

1
Q

Name 8 differences between pediatric and adult ECGs that you may see

A
  1. Faster heart rate
  2. Sinus arrhythmia is more common
  3. Right QRS axis (up to 3 months and again in adolescence)
  4. T wave inversions in the right precordial leads
  5. Dominant R wave in V1
  6. RSR’ pattern in V1
  7. Shorter PR interval and QRS duration
  8. Slightly longer QTc
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

How many seconds is each small box on an ECG?

A
  1. 04 seconds (40 ms)

- thus one large box is 5 small boxes = 0.2 seconds (200 ms)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

How do you count heart rate on an ECG the quick method?

A

300-150-100-75-60-50 (for each large square) between 2 consecutive R waves

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

How do you calculate heart rate for an irregular rhythm?

A

Multiply the number of QRS complexes on the rhythm strip by 6.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

What are causes of left axis deviation? (7)

A
  1. LBBB
  2. LVH
  3. AVSD
  4. Tricuspid atresia
  5. WPW
  6. TGA
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

What are causes of right axis deviation? (2)

A
  1. RVH

2. RBBB

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

What are the components of “normal sinus rhythm”?

A
  1. Upright P waves in leads I and AVF

2. P wave before every QRS complex

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

What does the P wave represent?

A

Atrial depolarization

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

What does the PR interval represent?

A

Reflects transit time of electrical impulse through the AV node (ie. in AV block, you see prolonged PR intervals)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

What are signs of left atrial enlargement on an ECG?

A
  1. Bifid P wave in Lead II
  2. Biphasic P wave in lead V1

**BOTH must also have prolonged P wave duration > 80 msec in infants and > 100 msec in children to qualify for left atrial enlargement

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

What are signs of right atrial enlargement

A
  1. P wave > 3 mm in lead II

2. P wave > 1.5 mm in lead V1

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

What are the 3 types of AV block?

A
  1. 1st degree AV block: Fixed prolongation of the PR interval
  2. 2nd degree AV block:
    - Mobitz Type 1 (Wenckebach): Progressive prolongation of the PR interval culminating in a non-conducted P wave. Can have atypical Wenckebach where the is no progressive PR interval prolongation but instead the PR interval of the first conducted P wave is shorter compared to the last conducted P wave
    - Mobitz Type 2: Intermittent non-conducted P waves without progressive prolongation of the PR interval
  3. 3rd degree (complete) AV block: independent atrial and ventricular activities; the P wave and QRS complexes are not at all associated.
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

What is a Q wave?

  • when is a Q wave considered pathological?
  • what is the clinical significance of a pathological Q wave?
A

A Q wave is any negative deflection that PRECEDES an R wave

  • Pathological Q waves:
    1. > 40 ms (1 mm) wide
    2. > 2 mm deep
    3. > 25% of depth of QRS complex
    4. Seen in leads V1-V3
  • pathological Q waves usually indicate current or prior myocardial infarction
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

What is the difference between a complete vs incomplete RBBB?

A

Complete RBBB - always abnormal, QRS duration > 100 ms in children ages 4-16 yo, > 90 ms in children < 4 yo

Incomplete RBBB - can be completely normal in the pediatric population and athletes - QRS duration 90-100 ms in children 4-16 yo, 86-90 ms in children < 4 yo

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

What are the causes of a complete RBBB?

A
  1. Post-intracardiac surgery (ie. repair of VSD and TOF
  2. Post cardiac catheterization
  3. ASD
  4. Ebstein anomaly
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

What are possible causes of a wide QRS complexes?

A
  1. RBBB
  2. LBBB
  3. Pre-excitation (eg. WPW syndrome)
  4. Ventricular rhythm (ie. premature ventricular contraction, V tach or V fib)
  5. Intraventricular block seen in hyperkalemia, TCA poisoning
17
Q

What are causes of large QRS voltages? (3)

A
  1. RVH or LVH
  2. BBB
  3. WPW syndrome
18
Q

What are causes of low QRS voltages? (5)

A
  1. Obesity
  2. Pericarditis
  3. Myocarditis
  4. Neonates (heart is less muscular)
  5. Hypothyroidism
19
Q

What is the normal progression of T waves in pediatric population?

A
  • 1st week of life: T waves in V1 MAY be positive, usually negative in V2-V4, V5 usually positive, V6 always positive
  • after first week of life: T waves become inverted normally in V1-V4! As the child ages, you will see T waves become upright starting in V4–> V1. This does NOT skip leads so if you see negative T waves that are out of sequence, this is abnormal! Usually this is due to lead misplacement. T waves should be positive in V5 and V6

**T wave inversion in leads V1-V4 in black/African athletes is normal

20
Q

What is the diagnosis for a pediatric patient (age < 7 yo) if you see upright T waves in V1?

A

Suggestive of RVH - such as pulmonary stenosis or TOF

21
Q

What is a U wave?

-differential diagnosis for a U wave?

A

An additional positive deflection after the T wave

DDx:

  1. Can be normal IF the voltage is < 25% of the T wave voltage, is in the same direction as the T wave, is more visible with slower heart rates
  2. Hypokalemia
  3. Bradycardia
  4. Digitalis toxicity
  5. Amiodarone toxicity
22
Q

What does the QT interval represent?

A

Time taken for both depolarization and repolarization of the ventricles

23
Q

How do you calculate the corrected QTc?

A

QT/square root of R-R

-remember to take the R-R interval between the R waves PRIOR to the measured QT interval

24
Q

What is the upper limit of the normal QTc range in boys vs. girls, pre puberty vs post puberty?
-what is considered a “borderline prolonged QTc”?

A

<15 years old:

  • boys: 450 ms
  • girls: 460 ms

> 15 years old:

  • boys: 440 ms
  • girls: 450 ms

***Borderline prolonged QTc is considered to be up to 480 ms. Anything above 480 ms is for sure prolonged!

25
Q

What is a quick way to eyeball whether QTc is prolonged?

A

QT interval should be less than half the preceding R-R interval

26
Q

What are the 4 stages of ECG changes seen in pericarditis?

A
  1. During first two weeks: diffuse ST elevation and PR depression with opposite seen in aVR
  2. Between 1-3 weeks: generalized T wave flattening
  3. After 3 weeks: flattened T waves become inverted
  4. Several weeks later: ECG returns to normal
27
Q

What are possible ECG findings in myocarditis?(7)

A
  1. AV conduction disturbances: PR prolongation, AV block, etc.
  2. Low QRS voltages (5 mm or less in all limb leads)
  3. Decreased T wave amplitude, negative or flat T waves
  4. QT prolongation
  5. Tachyarrhythmias - SVT or VT for example
  6. Pseudoinfarction pattern with deep Q waves and poor R wave progression in precordial leads
  7. ST segment elevation
28
Q

What are ECG findings of RVH?

A
  1. RAD
  2. Tall R waves in right sided leads: V1, V2, aVR
  3. Deep S waves in left sided leads: V5, V6, I
  4. R/S ratio in V1 and V2 is more than the upper limits of normal for age
  5. Upright T waves in V1 in children > 7 days to < 7 years (this is enough to diagnose RVH
29
Q

What are ECG findings of LVH?

A
  1. LAD
  2. Tall R waves in left sided leads: V5, V6, I
  3. Deep S waves in right sided leads: V1, V2, aVR
  4. R/S ratio in V1 and V2 less than lower limits of normal for age
  5. Inverted T waves in lead I and aVL AND left precordial leads (LV strain pattern)
30
Q

What is the ECG finding for hypocalcemia?

A
  1. ST segment prolongation

2. QTc prolongation

31
Q

What is the ECG finding for hypercalcemia?

A
  1. ST segment shortening

2. QTc shortening

32
Q

What are ECG findings for hyperkalemia?

A
  1. K > 6 - peaked tall T waves
  2. K > 7.5 - long PR interval, wide QRS duration, tall T wave
  3. K > 9 - absent P wave, sinusoidal wave
33
Q

What are ECG findings for hypokalemia?

A

K < 2.5 - depressed ST segment, biphasic T wave, prominent U wave

34
Q

What are ECG findings for WPW syndrome?

A
  1. Shortened PR interval
  2. Delta wave = slurring slow rise of the initial portion of the QRS
  3. QRS prolongation

Pediatric ECG (1 decks)

Brainscape helps you reach your goals faster, through stronger study habits.
© 2025 Bold Learning Solutions. Terms and Conditions