Indian Pediatr 2019;56:336
Procaterol for Infantile Sick Sinus Syndrome
Junya Nakajima* and Kayo Mizutani
Department of Neonatology, Kameda Medical Center,
Sick sinus syndrome (SSS) is a type of bradyarrythmia due to abnormal
pacemaking of a degenerated sinoatrial (SA) node; the pathophysiology
and optimal treatment of neonatal SSS remains unclear .
A male neonate was born at the gestational age of 30
weeks by emergency cesarean section due to maternal hypertensive
disorders of pregnancy. The patient’s body weight and length were 1361 g
(–0.80 SD) and 40.0 cm (–0.03 SD), respectively. His Apgar scores were
3, 5, and 8 at 1, 5, and 10 minutes after birth, respectively. After
resuscitation, including intubation, he was admitted to the neonatal
intensive care unit (NICU). Echocardiography revealed no structural
abnormality. After administration of indomethacin for eight times from
the 1st to 23rd days, the ductus arteriosus became narrower and
asymptomatic. On day 13, the first extubation was performed. Soon after
extubation, a recurrent attack of bradycardia with a heart rate of 50 to
80/min was observed, which required re-intubation and mechanical
ventilation. Holter electrocardiography (ECG) performed on day 17 showed
that an escaped rhythm occurred for 0.7% of the total 24 recorded hours,
leading to the diagnosis of SSS. Enteral administration of procaterol
via gastric tube with a dose of 0.65 µg/kg for three times/day was
initiated on day 21. The frequency of bradycardia reduced, and the
minimum heart rate increased above 90 beats/min, whereas his heart rate
at rest was elevated to 180–190 beats/min soon after initiating
procaterol. Therefore, procaterol was adjusted to 0.65 µg/kg/dose for
two times/day on the 22nd day. From the 34th day, procaterol was
increased to 1 µg/kg/dose for two times/day for prevention of
bradycardia after re-extubation. Holter ECG performed on day 34 showed
disappearance of the escape rhythm, and the patient was successfully
extubated on day 38. He is now 6 months of age, and the procaterol
therapy has been continued after the discharge. SSS is well controlled
and pacemaker implantation was not required.
Although the fundamental treatment for SSS is
pacemaker implantation, several problems, such as a small body size and
limitation of medical resources makes it difficult to apply it
immediately in the neonatal period, especially for preterm infants
[1-3]. The present case suggests the efficacy of enteral procaterol in
infantile SSS management.
Acknowledgments: Dr Hiroyuki Sato, Dr.
Atsushi Kondo, Dr Ayaka Tomita, Dr Yui Miyazawa, Dr Sato, Dr Kondo, Dr
Tomita and Dr Miyazawa for participating in treatment of the patient. We
also thank Ellen Knapp from Edanz Group (www.edanzediting.com/ac) for
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2. Epstein AE, DiMarco JP, Ellenbogen KA, Estes NA,
Freedman RA, Gettes LS, et al. ACC/AHA/HRS 2008 Guidelines for
Device-based Therapy of Cardiac Rhythm Abnormalities: A Report of the
American College of Cardiology/American Heart Association Task Force on
Practice Guidelines (Writing Committee to Revise the ACC/AHA/NASPE 2002
Guideline Update for Implantation of Cardiac Pacemakers and
Antiarrhythmia Devices): developed in collaboration with the American
Association for Thoracic Surgery and Society of Thoracic Surgeons.
3. Jaeggi E, Ohman A. Fetal and neonatal arrhythmias. Clin Perinatol.