Peadiatric Ecg

PEDIATRIC ECGs

OBJECTIVES 1.

Review Pediatric ECG Indications 2. Discuss some similarities and differences between Pediatric and Adult ECGs 3. Discuss pediatric arrhythmias

Successful use of Pediatric Electrocardiography Be

aware of age related differences in ECG indications

Know

N ranges for ECG variables

Recognize

typical differences in infants/children

 Syncope/seizure  Exertional symptoms  Drug ingestions  Tachyarrhythmia  Bradyarrhythmia  Cyanotic episodes  Heart Failure  Hypothermia

 Electrolyte

disturbance  Kawasaki disease  Rheumatic fever  Myocarditis  Myocardial contusion  Pericarditis  Post cardiac surgery  Congenital heart defects

Indications for a Pediatric ECG

“PAEDS ECG” + 2 Fs P- pericarditis (or

myocarditis), post cardiac surgery A-arrhythmias (tachy or bradyarrhythmia) E-exertional symptoms D-drugs, disease (Kawasaki) S-syncope/seizure

E-electrolyte

disturbance C-cyanosis, contusion (myocardial), cold (hypothermia) G- conGenital heart defects 2

Fs:

◦ Fever (rheumatic) ◦ Failure (heart)

Rarely ECG

cardiac in origin

NOT usually helpful in diagnosis

Consider

ECG for parent reassurance

Chest Pain in Kids

ECG Recording Distract child Limb electrodes

proximal, less movement

artifact Standard adult positions, but add V3R or V4R to detect right ventricular or atrial hypertrophy Standard paper speed (25 mm/s) and deflection (10 mm/mV)

AGE RELATED CHANGES IN NORMAL ECGs

The famous 1 complex, 2 segments, 2 intervals and 5 waves.

Heart

development during infancy and childhood causes differences in HR, interval durations, and ventricular dominance

Abnormal

adult ECG features may be Normal age-related changes in pediatrics

Pediatric ECG findings that may be Normal HR

> 100 bpm Right precordial T wave inversion Dominant RPLs R waves Short PR and QT intervals Short P wave and short QRS duration Inferior and lateral Q waves

Approach in reading Paediatric ECG

Heart Rate CO

= SV X HR

Higher

rate for infant’s high metabolic needs, small ventricle size cannot compensate by increasing SV (newborn commonly 120-160 bpm)

As

heart grows, SV increases. Higher rate no longer needed to produce adequate CO Rate gradually declines with age

RESTING HR Birth

140 bpm

1

yr: 120 bpm

5

yr: 100 bpm

10

yr: adult values

Amplitude varies little with age Best evaluated in II, V1, or V4R Wide P waves: L atrial hypertrophy Tall P waves (> 2.5 mm) in II: R atrial

hypertrophy Abnormal P patterns (ie inversion in II or aVF): atrial activation from site other than sinoatrial node

P wave

P

axis in range 0 to +90° P waves upright in I, II & aVF P wave duration 0.06s +/- 0.02s in children Max P duration 0.1s in children & 0.08s in infants. E.g if P axis is in range of +90 to + 180º what would u suspect in a normal healthy child?

P wave

P

wave + physiologic delay in AV node (PQ segment) Varies with age & HR. Age increases, HR decreases & PR interval increases in duration With the exception the PR interval is longer in duration at Birth than at infants period

PR Interval

PR Interval AGE from birth-1 yr, then Birth gradually increases t/o childhood 6m

Decreases

PR (ms) 80-160 70-150

1 yr

70-150

5 yr

80-160

10 yr

90-170

Ventricle Dominance Fetal

heart pumps blood to high resistance pulmonary circuit, so RV pressure high After birth: ◦ Pulmonary vascular resistance falls ◦ RV muscularity recedes ◦ RV contribution to ECG diminishes

Systemic

vascular resistance changes: increased LV size until > than RV (1 month) 6 months: RV/LV ratio similar to adults Shift from newborn RV dominance to LV dominance by 1 yr  RV dominance: R wave is larger than S wave in V1

Heart Changes LV/RV Weight Ratio

Neonates:

RV larger than LV, so Normal to have: ◦ Right axis deviation ◦ Large precordial R waves ◦ Upright T waves

30 weeks gestation

1.2 : 1

33 weeks gestation

1.0 : 1

36 weeks gestation

0.8 : 1

At birth

0.8 : 1

1 month

1.5 : 1

6months

2.0 : 1

Alduts

2.5 : 1

D3oL baby RAD Dominant R

in V4R/V1 Upright T in V1 Upright T persistence in RPLs > 1st wk: sign of RVH

12

year old ECG Normal adult axis R wave no longer dominant in R precordial leads

QRS axis  Mean

vector of Vent Depolarization process  Birth: ◦ mean QRS axis +125° with RAD ◦ up to 180° can be normal in newborn ◦ R waves prominent in R precordium ◦ S waves prominent in L precordium  Axis moves to Left as child ages

Newborn

+125°

1 month

+90°

3 years

+60°

adult

+50°

QRS  Ventricular

Depolarizati on time  QRS duration are short in the young infant & increases with age.

AGE

Birth

QRS duration (ms) < 75

6m

< 75

1 yr

< 75

5 yr

< 80

10 yr

< 85

Normal values in paediatric electrocardiograms

R wave (S Wave) Amplitude (mm)

Age

PR QRS duration (ms) Interval (ms)

Lead V1

Lead V6

Birth

80­160

< 75

5­26(1­23)

0­12 (0­10)

6 months

70­150

< 75

3­20 (1­17)

6­22 (0­10)

1 year

70­150

< 75

2­20 (1­20)

6­23 (0­7)

5 years

80­160

< 80

1­16 (2­22)

8­25 (0­5)

10 years

90­170

< 85

1­12 (3­25)

9­26 (0­4)

Q waves Depolarization

of Ventricular Septum Commonly in I,II,III & aVF Almost always in V5 & V6 but absent in V4R & V1 Duration is 0.02s & not > 0.03s In aVF & V5, max amplitude <6mm In V6, should be <5mm

R/S Progression In

patient > 3 years of age Progressive increase in R wave amplitude toward V5 Progressive decrease in S wave amplitude toward V6 1st month of life, complete reversal of R/S progression Btw 1mont & 3 years, partial reversal present with dominant R in V1 as well as in V5 & V6

T waves Ventricular repolarization T axis is more anterior with

upright T

wave in V1 T wave in V1 inverts (Posterior) by 7 days, stays inverted until 5 to 7 years then progressively more anterior in later years Upright T waves in right precordial leads (V1-V3) between 7d and 7yrs are ABNORMAL, usually RVH

QT interval Varies with HR but not age, except in infancy Must interpreted by Bazett’s formula QTc Important in recognition of congenital

prolonged QT syndrome, and medication effects (ie hyperK+, hypoCa++, dig, quinidine, procainaminde, Li+, tricyclics, phenothiazides)

QTc

should not exceed 0.44, except in infant where QTc of up to 0.49s may be normal for the 1st 6months of life.  (if can’t calculate, shouldn’t be > half R-R distance)

Occur

at the end of T wave Should not be included in QTc Represents the repolarization of Purkinje fibers Present in hypokalemia

U wave

Long QT syndrome in 3 yr old

ABNORMAL PAEDIATRIC ECGs

Ventricular Hypertrophy  “Voltage Criteria”: Depend on age adjusted values for R and S wave amplitudes

R wave (S wave) R wave (S wave) amplitude (mm) amplitude (mm) AGE

V1

V6

Birth

5-26 (1-23)

0-12 (0-10)

6m

3-20 (1-17)

6-22 (0-10)

1 yr

2-20 (1-20)

6-23 (0-7)

5 yr

1-16 (2-22)

8-25 (0-5)

10 yr

1-12 (3-25)

9-26 (0-4)

RVH Useful

ECG Features

◦ qR or rSR’ in V1 ◦ Upright T in RPLs: 7d-7yrs ◦ Marked right axis deviation (esp if with right atrial enlargement) ◦ Complete reversal of adult precordial pattern of R and S waves

Pediatric RVH  13

yr old  Transposition of great arteries, previous Mustard’s  RV

systemic ventricle: RVH  RAD  Dominant R in R precordial leads

Case: 6 m old with Cyanotic Episodes: ToF and RVH  Tall

R in

V1, reciprocal S in V6  qR in V3R and V4R  RAD 120*  Upright T V1-V3 (should be inverted)

LVH Useful

ECG Features

◦ Deep Qs in L precordial leads ◦ Lateral ST depression and T wave inversion

Some Congenital Heart Defects and ECG Manifestations  Anomalous

artery

L coronary

◦ Anterolat MI

 Anomalous

pulm venous return

◦ Total: RAD, RVH, RAH ◦ Partial RVH or RBBB

 Aortic

Stenosis

◦ LVH  Coarctation

◦ < 6m: RBBB or RVH ◦ > 6m: LVH, N, RBBB  Patent

ductus arteriosus ◦ Small shunt: N ◦ Mod: LVH, +/- LAH ◦ Large: CVH, LAH

Some Congenital Heart Defects and ECG Manifestations  Persistent

arteriosus

truncus

◦ LVH or CVH

 Pulm

atresia (and hypoplastic RV) ◦ LVH

 Tetralogy of Fallot ◦ RAD, RVH, +/- RAH

Transposition

◦ Intact septum: RVH, RAH ◦ VSD and/or PS: CVH, RAH, or CAH

Corrected

transposition

◦ AV blocks, WPW, LAH or CAH, absent Q in V5/V6, and qR in V1

ABNORMALITIES OF RATE AND RHYTHM

Abnormal HR Consider

systemic illness in any child with an abnormal HR

Sinus

tachycardia in babies and infants can be up to 240 bpm

Bradycardia:

consider hypoxia, sepsis, acidosis, intracranial lesions

Pediatric Arrhythmias Any

adult arrhythmia can occur in peds

Major

difference in pediatric ECGs is type of abN rhythms usually seen Most common pediatric dysrhythmias: SVT, bradycardia, and sinus arrhythmia AF,

atrial flutter, VT, or VF rare BUT: kids with congenital heart disease may have any arrhythmia

What should be done about this ECG?

Nothing! Sinus

arrhythmia common in children’s

ECGs Often quite marked

Sinus Arrhythmia  Inspiration:

increased blood flow to heart decreases vagal tone: increased HR  Expiration: increased vagal tone: lower HR  Marked in asthma, upper airway obstruction, increased ICP, and premature infants (immature autonomic innervation)  Must differentiate from AF  Rarely in infants but N in many kids/athletes, normally insignificant

Sinus Bradycardia Sinus

rate below N for age: 80 in newborn is sinus brady; 50 in athletic teenager is N

Common

in severe distress: hypoxia*/drugs

Can

be asymptomatic/insignificant (ie sleep/well-conditioned), treat if signs of poor systemic perfusion

SVT  Most common paeds  Can occur in healthy

arrhythmia infants and children

 Different

from sinus tach by unusually fast rate and patient presentation: ◦ ST usually physiologic: fear, fever, hypovolemia ◦ SVT: vague hx, child irritable, lethargic, feeding poorly, may present with signs of CHF

 Regular

rhythm > 220 (infants up to 280-320)

AV Blocks Uncommon:

atrial enlargement, surgical damage to AV nodal tissue, or congenital Same classification as adults 1st

degree AV block: must account for PR change with age. Can be N, or occur in rheumatic carditis, diphtheria, digoxin OD, and congenital heart defects

Other Arrhythmias AF/flutter:

rare in children Flutter: rheumatic heart dz, congenital defects, cardiac surgery, in utero, or N neonates VT: RARE, extremely abN: monomorphic associated with heart surgery; polymorphic (torsades) with long QT syndrome Aids to diagnose tachycardias (ie AV dissociation and capture/fusion beats) LESS common in kids

Other Arrhythmias Atrial

and Ventricular extrasystoles very common, usu benign if structurally N heart

VF:

RARE, only ~ 10% of terminal rhythm; congenital heart dz, prolonged resuscitation efforts, prolonged QT or long QT syndrome

Asystole:

common, least successfully resolved lethal peds arrhythmia; hypoxia and acidosis damage myocardium beyond repair

1.

Indications for Pediatric ECGs 2. Some differences between Pediatric and Adult ECGs 3. Common pediatric arrhythmias

What I Hope We Covered…

What You Should TRY to Remember…

Kids ‘n’ Adults SIMILARITIES  Conduction

pathways same, so waveforms (P, QRS, T) same, and waveform timing measured the same (i.e., PR, QRS, QT interval)

 Identical

approach to ECG analysis

DIFFERENCES  Kids:

fast HR that slows with age, shorter N intervals that prolong with age, and diminution of RV dominance

 Sinus

bradycardia, sinus arrhythmia and SVT most common arrhythmias in kids

Findings that may be N HR

> 100 bpm Right precordial T wave inversion Dominant R precordial R waves Short PR and QT intervals Short P wave and short QRS duration Inferior and lateral Q waves

REFERENCES ABC of clinical electrocardiograpy. Paediatric electrocardiography. Goodacre S, McLeod K. BMJ Volume 324. June 8, 2002. Pgs 1382-1385  ECG INTERPRETATION: WHAT IS DIFFERENT IN CHILDREN? Mowery, Bernice, Suddaby, Elizabeth C., Pediatric Nursing, 0097-9805, May 1, 2001, Vol. 27, Issue 3.  How to interpret Paediatric ECG by Gunneroth 