Untiring team effort cures a sick newborn with
cardiac rhythm disorders
A 16-day-old, sick child was brought to
BLK Super Speciality Hospital with a
history of persistently increasing heart
rate (tachycardia with HR of 300/
min). The patient was on ventilator in
a shock state. The baby was admitted
to NICU. Evaluation of cardiac
rhythm showed that the baby was in
Supraventricular Tachycardia (SVT,
ECG A). The baby's weight at the time
of admission was just 3.9 kilogram.
Echo result showed normal cardiac
anatomy with severe left ventricular
dysfunction.
Immediately after securing external
jugular vein access, 3 doses of
adenosine were given. However, there
was no response. Subsequently, direct
current synchronized cardioversion
(DC cardioversion) was given (4 joules
and 8 joules). Still, there was no
response, and the patient remained in
SVT rhythm.
Loading doses of metoprolol (0.4
mg) and amiodarone (5 mg/kg) were
given after which the baby regained
normal sinus rhythm. Following
this, maintenance doses of these two
medicines were started. After an hour,
the same tachyarrhythmia re-occurred
with HR of 300/min. Oral flecainide
was started along with metoprolol and
amiodarone injections, and normal
sinus rhythm was achieved again.
The following day, ECG was done
which showed a long QT interval
(QTc: 0.57 sec). As a result, flecainide
and amiodarone were discontinued as
both these medications cause long
QT interval.
Electrophysiology consultation
was sought which hinted that the
abnormal rhythm could probably
be due to pre-excitation (WPW
syndrome). The patient was advised
to stop metoprolol and to start with
esmolol injection. The same evening,
SVT happened again. Consequently,
boluses of metoprolol and amiodarone
were given and rhythm was reverted
to normal sinus rhythm. The same
medications were continued along
with metoprolol and amiodarone
infusion. Esmolol was stopped. The
next day, long QT happened again,
as a result amiodarone was stopped,
and metoprolol infusion (3mcg/kg/min)
was continued. There was no further
episode of SVT. Propranolol tablet was
started. After a 24 hour observation,
metoprolol injection was tapered over
the next 3-4 days. The patient was
extubated on the 3rd day.
The baby was discharged on oral
propranolol. Pre-discharge tests
showed normal left ventricle function
on echocardiography and normal sinus
rhythm along with normal QT interval
in ECG B.
Dr. Gaurav Agrawal
Consultant
Paediatric Cardiology
BLK Heart Centre
BLK Super Speciality
Hospital, New Delhi