Paeds Cardio Flashcards
What are the 4 defects in the tetralogy of Fallot?
- Pulmonary valve stenosis
- RV hypertrophy
- VSD
- Overriding aorta (takes blood from both the RV and LV)
Mnemonic is PROVe
- Pulmonic, RV, Overriding, VSD
How does squatting reverse a “Tet spell”?
Tet spells occur when vasodilation (ie with exercise) leads to a drop in systemic vascular resistance, leading to worsening of the R) to L) shunt
Can also occur with increase pulmonary resistance such as with crying, hyperventilating, straining (ie with defecation) valsalva and feeding
Other causes include infection, pain, dehydration and on waking from sleep
Squatting reduces overall 02 consumption by resting, and occludes the arteries supplying the legs leading to sudden increase in SVR, reversing the shunt back to L) to R)
Opiates such as Morphine are also used (0.1mg/kg IV). They suppress respiratory drive, reduce pulmonary resistance, reduce tachycardia and overall 02 demand
What other defects must be present for a neonate with TGA to survive?
PDA
VSD
Cardiac issues presenting to ED by age in infants
<1 month likely duct dependent
>1month likely heart failure
What clinical features are red flags for cardiac defects?
Persistent cyanosis
Murmurs and active praecordium (praecordial thump)
Absent femoral pulses
Faltering growth
Persistent tachypnoea/tachycardia
Palpable liver edge
Gallop rhythm
What are the causes of ischaemic looking ECG’s in young children (STD and STE)?
Ischaemia!
ALCAPA (Anomalous left coronary arising from pulmonary artery)
Peri/Myocarditis
Hypotension with global hypoperfusion
How can you treat a child having a tet spell?
Ketamine for sedation
morphine to reduce RR
metaraminol increase SVR
Squat patient
02
cautious fluids
What are the main causes of syncope in kids <6yo?
seizures
breath holding spells
cardiac disorders
Vasovagal uncommon <6yo
How is acute rheumatic fever diagnosed (ARF)?
two major criteria
or
One major and two minor criteria
+
Evidence of preceding strep A infection
What are the Major criteria for ARF?
- Carditis
- Polyarthritis (Aseptic monoarthritis in high risk groups)
- Sydenham chorea
- Subcutaneous nodules
- Erythema marginatum
What are the minor criteria for ARF
- Fever >38.5C
- Polyarthralgia or aseptic monoarthritis
- Prolong PR interval on ECG
- CRP >30
- ESR >30 high risk, >60 low risk
When should juvenile t waves begin to resolve?
Appears about 7 days old
Disappears approx 7 years of age
Unclear why newborns <7 days old don’t have this
What is a rough guide to evaluating paeds ECG’s?
Rate
Rhythm
Axis
Intervals
Evaluate juvenile t waves
Assess for LVH and RVH
When does the paeds heart rate roughly equate to an adults heart rate?
After 6yo
What are the most common causes of sinus bradycardia in children?
Aerobically fit child (most common)
Hypothyroidism
Long QT syndrome
What is the most common cause of 2nd degree AV block in infants?
Babies of mothers with SLE (self limiting)
Primary SLE
Post congenital heart disease surgery
What is the most common causes of junctional rhythms (firing from AV node) in infants?
infection
desaturation
vagal stimulation
diving reflex (ie ice bath)
What is the most common cause of VT in paeds?
Very uncommon in paediatrics, most of the time a wide complex tachycardia is SVT with aberrancy (95%)
Most common causes
Congenital heart disease
Drugs
Myocarditis
What is the most common causes of 1st degree HB in kids?
PR interval shorter in paeds, approx 120msec (3 small boxes)
Normal variant
myocarditis
Acute rheumatic fever
hyperkalaemia
ASD
Ebsteins anomaly
What is normal for the QRS axis in paeds?
- QRS normally positive in AVF
- QRS may or may not be down in I
- R) axis deviation normal until about age 6yo, should be adult axis >6yo
What is the most common signs of RVH in paeds?
Lack of juvenile T waves
Larger terminal R’ wave in V1 (rSR, compared to RSr)
What are the normal findings in a paeds ECG?
RSr pattern in V1
Juvenile T waves
Rightward axis
Dominant R waves in V1-3
Marked sinus arrhythmia
Rapid heart rate compared to adults
Longer Qtc (<490msec)
Q waves in the inferior and L) precordial leads
Slightly peaked p waves (<3mm)
Shorter PR (<120msec) and QRS (<80msec) durations
What is the typical cardiac abnormality in down’s syndrome?
Atrioventricular septal defect 37%
Isolated VSD 31%
How does dextrocardia appear on an ECG?
Northwest (extreme axis)
All S waves dominant in precordial leads
