Occasional reviewTwelve instructive electrocardiograms for the paediatrician
Section snippets
Syncope
A 10-year-old boy was brought to the Emergency Department after fainting whilst sprinting at school. He had been previously well. The episode was brief and he was immediately alert after the event. His ECG is shown in Figure 1. His corrected QT interval is significantly prolonged and after exclusion of myocardial and electrolyte abnormalities, is diagnostic of Long QT syndrome. He subsequently proved to have a mutation in KCNQ1 (Long QT 1).
Long QT syndrome is an important cause of syncope and
Palpitations and dizzy episodes
A 10-year-old girl presents after a 10-min episode of sudden onset, sudden offset palpitations associated with dizziness and chest discomfort. Her ECG is shown in Figure 2a. She has Wolff Parkinson White Syndrome. Figure 2b, from a different patient has the same diagnosis but the findings are considerably more subtle and could be missed with a cursory examination of the ECG.
Collapse
A 15-year-old previously well girl collapsed a school whilst playing sport. She was taken to her local Emergency Department. She was drowsy, pale and diaphoretic. Her pulse was thready, fast and irregular.
Her 12-lead ECG is shown in Figure 3. She had an irregular wide complex tachycardia. The patient was anaesthetised and a synchronized biphasic DC shock cardioverted her to sinus rhythm. A repeat 12-lead ECG revealed a short PR interval and pre-excitation consistent with Wolff Parkinson White
Unwell neonate
A 2-week girl presented to the emergency department pale, breathless and refusing feeds. A tachycardia was noted (Figure 4). She has supraventricular tachycardia with obvious retrograde P waves. Adenosine was administered converting the babe to sinus rhythm. No pre-excitation was present.
The ECG is consistent with supraventricular tachycardia. The mechanism is the same as in Wolff Parkinson White syndrome however the pathway in this case was only unidirectional and does not conduct downwards in
Screening ECG
A 4-day-old infant with Trisomy 21 had a screening ECG performed (Figure 5). The automated report read: ‘Sinus rhythm. Right axis deviation. Consider anterior ischaemia. Abnormal ECG’. The ECG however is normal for age.
The ECG of the newborn is very different to that of an adult in a number of ways and will progressively change from newborn to childhood to adolescence and then adulthood. Automated ECG reports may not have paediatric algorithms or the algorithm is not used if the date of birth
Lethargy and malaise
A 6-year-old boy sees a paediatrician for lethargy and malaise and a baseline tachycardia with irregularity is noted. An ECG is performed (Figure 6).
Atrial ectopic tachycardia (also called focal atrial tachycardia) originates in the either atrium from a focus other than the sinus node. The P waves usually have an abnormal axis. The tachycardia has an ‘automatic’ basis and often has wide variation in rate (‘warm up’ – ‘cool down’). There may be varying degrees of atrioventricular block. The
Shortness of breath
A 2-year-old boy came to the emergency Department because of laboured breathing. He had clinical evidence of cardiac failure and a baseline tachycardia between 130–150 bpm. His ECG is shown in Figure 7.
Whilst not diagnostic, this ECG is typical for the so-called ‘permanent form of junctional reciprocating tachycardia’ (‘PJRT’). The P waves have an abnormal axis and are inverted in leads II, III and aVF. The differential diagnosis is atrial ectopic tachycardia arising from the low right atrium.
Seizure
A 3-year-old girl was taken to a local hospital via ambulance after a seizure at home. There was no significant past history and no known history of drug ingestion. She was lapsing in and out of consciousness. Her presenting ECG is shown in Figure 8a. It shows ventricular tachycardia and then probable sinus rhythm with first degree atrioventricular block, a broad QRS complex with a right bundle branch block pattern and some premature beats.
After intubation a second ECG was obtained (Figure 8b).
Incidental bradycardia
A 5-year-old boy who is admitted to hospital after fracturing his arm after a fall from his bike. Routine observations note heart rate of approximately 50 bpm. Observations are otherwise normal. An ECG was performed showing complete atrioventricular block (Figure 9). In retrospect his parents commented that he is more tired of an evening than his brothers and that he sleeps poorly. His asymptomatic mother was positive for anti-Ro/SSA antibodies and it was presumed he had undiagnosed congenital
Palpitations and pre-syncope
A 9-year-old boy had sudden onset of palpitations and pre-syncope whilst sitting in math class. He was transferred to the closest Emergency Department. His ECG is shown in Figure 10. The diagnosis of supraventricular tachycardia was made, however adenosine was given but failed to revert him to sinus rhythm. After the diagnosis was appreciated he was reverted to sinus rhythm using intravenous verapamil.
Belhassen’s ventricular tachycardia is a relatively narrow complex (but still broad complex),