Australian Doctor 12th July Issue 2024 | Page 25

HOW TO TREAT 25
ausdoc . com . au 12 JULY 2024

HOW TO TREAT 25

loud that it becomes palpable , such as in Eisenmenger syndrome . 34 An ECG is helpful as it shows RV hypertrophy .
The heart rate is slower in later childhood and adolescence , so it may then be possible to separate the two components of the second heart sounds , where a louder second component ( pulmonary closure ) suggests pulmonary hypertension .
Pulmonary primary hypertension is rare and , despite the current available management , still has a poor longterm prognosis . There is often a delay of six months or longer before the diagnosis is considered , particularly in a child with increasing breathlessness on exertion . Identifying a louder pulmonary closure suggests pulmonary hypertension , further aided by an ECG showing RV hypertrophy . Confirmation of the diagnosis and starting appropriate treatment may improve the short- and long-term outlook . 35
Pulmonary hypertension may occasionally be the only sign pres-
Alicia Fagerving ( WMSE ), Laboratoires Servier / CC BY-SA : bit . ly / 3wXlMxq
Box 2 . Features that should prompt referral in infancy and childhood
• Tachypnoea .
• Differential pulses .
• Cyanosis .
• Poor weight gain .
• If the infant or child is dysmorphic or has syndromic features suggestive of a genetic disorder .
• Genetic disorders , even in the absence of a murmur , may warrant referral because a cardiac abnormality — either a congenital anomaly or a cardiomyopathy — may be present . — For example , children with a hypermobility connective tissue disorder may develop mitral valve prolapse and mitral incompetence , a dilated aortic root and ascending aorta and require long-term surveillance .
ent despite a serious congenital heart
Source : Rashed ER et al 2022 33
abnormality , such as cor triatriatum ,
supravalvular mitral stenosis , a parachute
mitral valve or a smallish LV .
unrecognised cardiac abnormality , is
There are generally no murmurs . 34 The rise in the pulmonary venous
rarely found . A careful history may uncover a
pressures leads to a rise in the pulmo-
history of asthma ; the parents some-
nary arterial pressures as evidenced
times refer to this as bronchitis or
by a louder pulmonary closure or
bronchiolitis , which has now evolved
summated second heart sound in the pulmonary area . Diagnosis and appropriate treatment of surgically
into exercise-induced bronchospasm . 38 The development of a cough and wheeze , especially on stopping
correctable lesions may result in good
the exercise , supports the diagnosis .
long-term outcomes .
Provocative pulmonary function studies
may be helpful or , alternatively , a
PALPITATIONS
therapeutic trial with a bronchodilator
This symptom , especially common
before sustained activity may aid the
in later childhood and adolescence ,
diagnosis .
is rarely associated with an arrhythmia . 12 The issues related to the diagnosis of SVT in the newborn and in early
Figure 5 . Coarctation of the aorta .
CHEST PAIN Left-sided chest pain is common and
infancy have been discusses earlier . 29
usually attributed to the heart . How-
The presence of pre-excitation on
ever , such pain is often experienced
the interval ECG indicates an ante-
while at rest and rarely with exer-
grade conducting pathway . A normal
cise , with the child able to run with-
ECG does not exclude an accessory
out developing chest pain . Ischaemic
pathway with retrograde conduc-
chest pain is rare in childhood .
tion . A careful history may suggest
Consider ischaemic pain in any
ectopic beats rather than palpitations ;
child / adolescent who has had Kawa-
patients complain of a strong beat
saki disease and has persistent cor-
that relates to the post-ectopic beat , which has a greater stroke volume because of greater filling of the ven-
onary aneurysms , especially a giant aneurysm . 9 If in doubt , especially in older children or adolescents , a stress
tricles . A 24-hour Holter will deter-
exercise test can be helpful .
mine whether the ectopics are atrial
Be mindful that non-specific chest
or ventricular in origin , as well as the
pain may be a manifestation of myo-
overall ectopic load . Treatment is sel-
carditis / pericarditis as was seen in the
dom required and is only necessary if
recent COVID-19 pandemic following
there are runs of ectopics , especially arising from the ventricle .
11 , 39 the Pfizer and Moderna vaccines . Occasionally , adolescents may present
The sudden onset and sudden
with a giant pericardial effusion asso-
decay of a rapid heart rate suggest a
ciated with non-specific chest pain . 40
probable diagnosis of an arrhythmia ,
Rarely , there is an anomalous ori-
such as SVT . This is almost the only
gin of the coronary arteries , especially
tachyarrhythmia seen in childhood and
the left coronary artery arising from
adolescence , particularly if the heart is normal .
In contrast , a sudden onset followed by a gradual decay , or a gradual onset and decay , is unlikely to be caused by
Figure 6 . Neonatal post ductal pulse oximetry .
the order of 150-160bpm ; this may
frequently disappear ; they rarely lead
cardiac electrophysiologist is war-
the right coronary sinus ; this may lead to ischaemic or non-specific chest pain . The anomaly is usually readily detected on echocardiogram . 41 If in doubt , a CT angiogram will clarify the
an arrhythmia . Consider other causes
be slightly irregular compared with a
to EAT .
ranted as the diagnosis is complex , the
diagnosis . Localised coronary artery
for the probable sinus tachycardia .
regular rapid heart rate of the order
An exercise stress test may be indi-
treatment problematic and the out-
stenosis remains a nightmare — even
Adolescents are usually able to dis-
of 180bpm or more seen with SVT .
cated if there are multifocal ventricu-
come guarded . 37
for the cardiologist .
tinguish between the rapid heart rate
The diagnosis is made even more dif-
lar ectopics to exclude the possibility
experienced with exercise and the
ficult as the ectopic atrial focus often
of catecholaminergic polymor-
BREATHLESSNESS WITH ACTIVITY
CARDIOMYOPATHY
rapid heart rate that may arise with the
looks like a normal P wave . A 24-hour
phic ventricular tachycardia . This is
Children and adolescents with breath-
A family history of cardiomyopathy
onset of an arrhythmia . Documenting
Holter is helpful , particularly if there
important as catecholaminergic pol-
lessness while playing sport are often
prompts referral of children for an
an episode of the tachycardia is essential to make a diagnosis , initiate appropriate intervention and transition from
is a high average rate that fails to settle overnight . Note that a prolonged delay in the diagnosis of EAT may
ymorphic ventricular tachycardia may result in sudden death in otherwise-healthy children . 36
referred for exclusion of a cardiac cause . Further investigation may be warranted if their shortness of breath is worse
echocardiogram to ensure they do not have a similar problem . 42 If a genetic cause is found in the index patient , and
oral medication to an electrophysiol-
result in a dilated cardiomyopathy
Sudden collapse , especially if
than that experienced by their peers
this is not detected in the child , ongo-
ogy study and ablation .
from the incessant tachycardia . Atrial
occurring after activity , raises the pos-
with the same degree of physical activ-
ing surveillance and echocardiograp-
Ectopic atrial tachycardia ( EAT )
ectopics are common prenatally and
sibility of a channelopathy , such as
ity . However , a cardiac cause , such as
ghy are not needed . That is particularly
may produce a raised heart rate in
into the newborn period and then
prolonged QT interval . Referral to a an underlying cardiomyopathy or an important in children of a parent with