The Pediatric ECG

DR MANDAR HAVALDR MANDAR HAVAL

DCH.DNBDCH.DNB

Objectives

Review the cardiac physiology with respect to age, and age related normals

Discuss wave morphology and axis as it relates to age and ventricular dominance

Review intervals and other “differences” in the pediatric ECG

Discuss an approach to interpretation of chamber enlargement

Review some basic tachyarrythmias common in children

Normal variants and osce on ECG

Background

ECG changes during the first year of life reflect the switch from fetal to infant circulation, changes in SVR, and the increasing muscle mass of the LVThe size of the ventricles changes as the infant grows into childhood and adulthoodThe RV is larger and thicker at birth because of the physiologic stresses on it during fetal developmentBy approximately 1 month of age, the LV will be slightly largerBy 6 months of age, the LV is twice the size of the RV, and by adolescence it is 2.5 times the size

Heart rate Average heart rate peaks at second month of life, then

gradually decreases

Resting HRs start at 140 bpm at birth, fall to 120 bpm at 1 year, 100 bpm at 5 years, and adult ranges by 10 years

• • INTRINSIC HEART RATESINTRINSIC HEART RATES

Newborn to 3 years:Newborn to 3 years:

• SA node 95 – 120

• AV node (junctional) 45 – 85

• Purkinje (ventricular) 35 – 55

3 years to teenager

• SA node 55 – 120

• AV node (junctional) 35 – 65

• Purkinje (ventricular) 25 ‐ 45

Age Related Normal Findings

Tables exists that include age based normal ranges for heart rate, QRS axis, PR and QRS intervals, and R and S wave amplitudes

After infancy, changes become more subtle and gradual as the ECG becomes more like that of an adult

The P Wave

Best seen in leads II and V1

P wave amplitude does not change significantly during childhood

Amplitudes of 0.025 mV should be regarded as approaching the upper limit of normal

The QRS Complex

QRS complex duration is shorter, presumable because of decreased muscle mass

QRS complexes > 0.08 sec in patients < 8 years is pathologic

In older children and adolescence a QRS duration > 0.09 sec is also pathologic

The T Wave

The T waves are frequently upright throughout the precordium in the first week of lifeThereafter, T waves in V1-V3 invert and remain inverted from the newborn period until 8 years of ageThis is called the “juvenile T wave pattern”, and can sometimes persist into adolescenceUpright T waves in the right precordial leads in children can indicate right ventricular hypertrophy

3 day old & 7 y/o

QRS Axis and Ventricular Dominance

At birth, the axis is markedly rightward (+60 - +160), the R/S ratio is high in V1 and V2 (large precordial R waves), and low in V5 and V6As the LV muscle mass grows and becomes dominant the axis gradually shifts (+10 - +100) by 1 year of age, and the R wave amplitude decreases in V1 and V2 and increases in V5 and V6

What is the axis?

What is the axis?

LAD

NormalRAD

Lead I

AVF

Negative

+

+_

Lead I AVF

Normal Positive Positive

RAD Negative Positive

LAD Negative Negative

What is the axis?

RIGHTAXISDEVEATION

What is the axis?

LAD

What is the axis?

NORMAL

CHAMBER HYPERTROPHY

Interpretation?

Right atrial enlargement Right atrial enlargement

DIGNOSIS?

Left atrial Left atrial enlargementenlargement

Atrial Enlargement

RAE is diagnosed in the presence of a peaked tall P wave in II

In the first 6 months, the P wave must be >3 mm to be pathologic; then >2 mm is abN

LAE can be diagnosed with a biphasic P wave in V1 with a terminal inferior component

The finding of a notched P wave in II can be a normal variant in 25% of pediatric ECGs

Interpretation?

Right ventricular hypertrophy (RVH)

RVH

Large R wave in V1 and large S wave in V6

Upright T wave in V1-V3

RAD

Persistent pattern of RV dominance

Right Ventricular Hypertrophy

Diagnosis depends on age adjusted values for R wave and S wave amplitudesA qR complex or rSR’ pattern in V1 can also be seenUpright T waves in the right precordial leads, RAD, and complete reversal of adult precordial pattern of R and S waves all suggest RVH Lead V1with the R height

> 15 mm IN < 1YR & >10mm IN > 1 YR

RVHRVH

Interpretation?

Left ventricular hypertrophy (LVH)

LVH

R wave > 98th percentile in V6 and S wave > 98th percentile in V1

LV “strain” pattern in V5 and V6 or deep Q waves in left precordial leads

“Adult” precordial R wave progression in the neonate

CONDUCTION CONDUCTION ABNORMALITIESABNORMALITIES

Bundle branch blocks are diagnosed as they would be in adults; RBBB occurs most commonly after repair of congenital heard defects and LBBB is very rare

First degree AV block and Mobitz type 1 (Wenckebach) can be a normal variant in 10% of kids

Complete AV block is usually congenital or secondary to surgery

Sinus Bradycardia

Deviation from NSR

- Rate < 60 bpm Etiology: SA node is depolarizing slower than

normal, impulse is conducted normally (i.e. normal PR and QRS interval).

Sinus Tachycardia

Deviation from NSR

- Rate > 100 bpmEtiology: SA node is depolarizing faster than normal, impulse is conducted normally.

Remember: sinus tachycardia is a response to physical or psychological stress, not a primary arrhythmia.

Interpretation?

Sinus Tachycardia

1st Degree AV Block

Etiology: Prolonged conduction delay in the AV node or Bundle of His.

Diagnosis?

p

1st Degree AV Block

FIRST DEGREE HEART FIRST DEGREE HEART BLOCKBLOCK

PR interval > 5 small divisions, 0.2 secs

Causes: myocarditis, acute rheumatic fever, drugs,

50 bpm• Rate?• Regularity? regularly irregular

nl, but 4th no QRS

0.08 s

• P waves?

• PR interval? lengthens• QRS duration?

Interpretation? 2nd Degree AV Block, Type I

2nd Degree AV Block, Type I

Deviation from NSR PR interval progressively lengthens, then

the impulse is completely blocked (P wave not followed by QRS).

40 bpm• Rate?• Regularity? regular

nl, 2 of 3 no QRS

0.08 s

• P waves?

• PR interval? 0.14 s• QRS duration?

Interpretation? 2nd Degree AV Block, Type II

2nd Degree AV Block, Type II

Deviation from NSR Occasional P waves are completely

blocked (P wave not followed by QRS). Etiology: Conduction is all or nothing (no

prolongation of PR interval); typically block occurs in the Bundle of His.

MOBITZ TYPE 2

Rhythm #13

40 bpm• Rate?• Regularity? regular

no relation to QRS

wide (> 0.12 s)

• P waves?

• PR interval? none• QRS duration?

Interpretation? 3rd Degree AV Block

Diagnosis?

3rd Degree AV Block

Diagnosis?

RBBB

RIGHT BUNDLE BRANCH RIGHT BUNDLE BRANCH BLOCKBLOCK

Wide QRS > 0.12 s ( 3 small divisions)

M morphology in V1V1

“Rabbit Ears”

Diagnosis?

LBBB

LEFT BUNDLE BRANCH LEFT BUNDLE BRANCH BLOCKBLOCK

Wide QRS > 0.12 s ( > 3 small divisions)

M morphology in V 6 and W in V1

ARRHYTHMIAS

13 y/o with palpitations

Paroxysmal supraventricular tachycardia (PSVT)

22 day old with poor feeding

Paroxysmal supraventricular tachycardia (PSVT)

Diagnosis?

Paroxysmal supraventricular tachycardia (PSVT)

Paroxysmal supraventricular tachycardia (PSVT)

Regularity: Regular

Rate : >180/min

P wave morphology: Different from sinus P wave or lost in preceeding T wave

PR interval: 0.12 – 0.20 secs ( normal)

QRS interval: normal (<0.08 s)

Pattern: Sudden onset and offset

Diagnosis

What is the rate?

Is the QRS wide or narrow?

Causes

Ventricular tachycardia

Ventricular tachycardia

Rate > 120 / min

QRS > 0.08 secs

Causes: myocarditis, LCAPA, tumour, Long QT, drugs, surgery

Diagnosis?

Torsades de pointis

Torsades de pointis

Torsades de pointis

Gradual change in amplitude of QRS

Rate 150-250/min

Prolonged QT interval, Hypokalemia, hypomagnesemia, drugs

Diagnosis?

Ventricular fibrillation

Chaotic rhythm with wide QRS

Causes: terminal rhythm in cardiac arrest

70 bpm• Rate?• Regularity? regular

flutter waves

0.06 s

• P waves?

• PR interval? none• QRS duration?

Interpretation? Atrial Flutter

Atrial Flutter

Deviation from NSR No P waves. Instead flutter waves (note

“sawtooth” pattern) are formed at a rate of 250 - 350 bpm.

Only some impulses conduct through the AV node (usually every other impulse).

QUESTIONS

1. 2 year old with syncope and VT

LONG QT SYNDROMELONG QT SYNDROME

Intervals

PR and QRS durations are relatively short from birth to age 1 and gradually lengthen during childhood; corrected QT (QTc) should be calculated on all pediatric ECGs

During the first 6 mo of life, the QTc is slightly longer and is considered normal below 0.49 sec

After that, any QTc above 0.44 sec is abnormal

Other features of long QT syndrome include notched T waves, abnormal U waves, relative bradycardia and T wave alternans

LONG QT SYNDROMELONG QT SYNDROME

LONG QT – SYNDROME.

N-QTc- Infants 0.44 & NB-0.49sec

1.Beta-Blockers .Avoid drugs known to prolong QT-interval , electrolyte imbalance.2.SOS pacemaker . W/F Syndromes associated with Long QT-interval.3. Avoid competitive sports and swimming, teach CPR to the caretakers. Inform about SIDS.

14-year old girl

•Asymptomatic now

•Intermittent palpitations, no syncope

•SO2: 94%

•Split S2, multiple heart sounds, no murmurs

CASE 2CASE 2

EBSTEIN ANOMALY

Sinus, Tall P, splintered QRS

CASE 3  DILATED CARDIOMYOPATHYDILATED CARDIOMYOPATHY

There is marked LVH (S wave in V2 > 35 mm) with dominant S waves in V1-4.

Right axis deviation suggests associated right ventricular hypertrophy (i.e. biventricular enlargement).

There is evidence of left atrial enlargement (deep, wide terminal portion of the P wave in V1).

There are peaked P waves in lead II suggestive of right atrial hypertrophy (not quite 2.5mm in height).

4. INTRPREAT ECGHYPERKALEMIA

• Changes appear when K+ falls below about 2.7 mmol/l• Increased amplitude and width of the P wave• Prolongation of the PR interval• T wave flattening and inversion• ST depression• Prominent U waves (best seen in the precordial leads)• Apparent long QT interval dueto fusion of the T and U waves

HYPOKALEMIA- HYPOKALEMIA- ECGECG

5.

WPW SYNDROMEWPW SYNDROME6.6.

69

Delta wave

•WPW- 3 features

•Short PR interval ,

•Delta wave on upstroke of QRS

•Slightly wide QRS

Station 1.a 1 day old neonate with respiratory distress ECG done

What are ECG features?

What is diagnosis?

What disorders are associated?

What precaution to be taken in emergency with such patients

7)

Inverted p/t wave, -ve qrs in lead 1.lead 2 n 3 reversed.lead 2 resemble 3 and 3 resemble 2

DEXTROCARDIA

number of bowel, esophageal, bronchial and cardiovascular disorders (such as double outlet right ventricle, endocardial cushion defect and pulmonary stenosis) Kartagener syndrome

Place rt Up N lt Lo lead on Up lft N Lo rt

ATRIAL FIBRILLATIONATRIAL FIBRILLATION8.

Atrial activity is chaotic

Station No;9A 10 day old newborn was rushed to NICU by a local doctor as he found

different pattern of his cardiac activity. O/E child had fine rashes over the face specially the periorbital area . ECG done in ER showed (1x5=5)

a) What is the ECG diagnosis? b )What is probable diagnosis?

c) What is the pathogenesis of this disease?

d) What is the Rx of this acute stage?

e) What is the earliest age at which this cardiac defect can detected antenatally?

A)COMPLETE HEART BLOCK

b) Neonatal Lupus

c) Transfer of anti Ro antibodies between 12-16 wks of gestation

d) Cardiac pacing

e) 16 wks of GA

10

2 months old baby admitted with recurrent cough cold, irritability, dyspnea and sweating. EKG done What is the diagnosis? (1/2)Name 4 EKG findings that helped u in diagnosis (1)What is the diagnostic test?(1/2)Name treatment options of it.(1)

Answer

ALCAPAALCAPA

Inverted T wave, V5-V6 deep Q wave,ST elevation , inverted T wave

Cardiac catherization

Medical t/ t for CCF, ishamia and Surgical excision and ligation

 ALCAPA_ECG # Description : ECG. Left axis deviation with left ventricular hypertrophy. Signs of anterolateral myocardial infarction: deep Q waves with T waves inversions in leads I, avL and deep Q waves with ST elevation in the left precordial leads.

A 12 yr old male child with c/o jt pain and fever admitted in ER.ECG done showed.What does this EKG strip shows (1)Name 3 EKG findings that helped you in diagnosis (1)What are the 2 clinical findings which will indicates severity?(1)Name treatment options of it.(1)What are other differential diagnosis?(1)

11

Answer

RHEUMATIC PERICARDITIS

Low voltage QRS, elevation of ST, Twave inversion

Friction Rub and Pulsus Paradoxus

steroid

Viral Pericarditis, Benign Pericarditits, JRA

PERICARDITIS

Diffuse upsloping ST segment elevations seen best here in leads II, III, aVF, and V2 to V6

1212

MYOCARDITISMYOCARDITIS

Sinus tachycardia with non-specific ST segment changes

1313

14

Name the wave marked by the asterisk

In which condition will you find it?

Which serious arrhythmia can it lead to?

How will you treat it?

J WAVE,OSBORNE WAVE

Hypothermia

Ventricular arrhythmia

Rewarm the patient

ECG showing R wave in lead V1 with RS in V2 (sudden transition), Right axis deviation , no q waves in lateral leads suggesting decreased pulmonary blood flow 

TETROLOGY OF FALLOT (TOF)15

PERICARDIAL EFFUSION

Sinus tachycardia with low QRS voltage and QRS alternans

16

ASDASD

There is right axis deviation with tall R waves V1-3 and  corresponding deep S waves in V4-6. T waves are flat in V1 and inappropriately upright in V2-3. There is the RsR' pattern in V1 of partial rightbundle branch block.

17

VSDVSD

The Katz-Wachtel sign Katz-Wachtel sign is tall diphasic RS complexes at least 50 mm in height in lead V2, V3 or V4 – mid precordial leads

1818

PREMATURE BEATS

Premature Ventricular Contraction

Premature Atrial Contraction

Normal Variants

Sinus arrythmia Can be quite marked Slows on expiration and

speeds up on inspiration

Extrasystoles Can be atrial or venticular

and are usually benign in the context of a structurally normal heart; typically monomorphic and associated with slower heart rates

Abolish with excercise

The Pediatric ECG…

In Summary

Consider the age of the child, and the cardiac forces that may be dominantUse a structured approach and assess morphology, axis, and intervals in the context of age related normalsEvaluate for the presence of structural diseaseRemember the “normal variants”

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