sinus node dysfunction with prolonged pauses is a rare finding in children unless they have had prior congenital heart surgery .
abrupt termination of a supraventricular tachycardia ( svt ) or pacing can be associated with sinus pauses due to overdrive suppression of the sinus node . however , such pauses are rarely seen in children despite the common prevalence of paroxysmal supraventricular tachycardia ( psvt ) perhaps because of the relative healthy state of the sinus node .
we describe a case of long sinus pauses in a teenager with an asymptomatic ectopic atrial tachycardia .
treatment with radiofrequency catheter ablation of the underlying tachyarrhythmia led to resolution of the sinus pauses .
an asymptomatic 14 year old boy was referred for evaluation of an irregular heart rhythm noted during a routine checkup .
a standard 12lead electrocardiogram revealed short runs of an atrial tachycardia ( fig .  1 ) .
an ambulatory 24 hour holter monitor done to assess the frequency and behavior of the tachycardia showed frequent sinus pauses ( fig . 
2 ) with a longest pause around 5  s. the pauses were mostly ( but not always ) associated with termination of the svt .
because of the concerns of the long sinus pauses and because we felt that pharmacologic therapy could lead to worsening of the pauses , he was taken up for catheter ablation . at the ablation procedure
, he was found to have an ectopic atrial tachycardia arising within the right atrial appendage .
the ectopic focus was mapped with three dimension electro anatomical mapping ( carto , biosense webster ) , and successfully ablated .
post ablation , he showed no sinus pauses with atrial burst pacing ( normal corrected snrt ) and holter monitor done one week later showed normal sinus rhythm with no pauses , and no sinus bradycardia ( lowest heart rate was 42 ) .
sinus node dysfunction with long sinus pauses is rare in children with an otherwise normal heart .
while sinus pauses due to overdrive suppression of the sinus node in the context of atrial fibrillation is described in adults , it has not been reported in children , .
adult reports have shown that ablation of the atrial fibrillation can lead to resolution of the sinus pauses , . however , it is unclear whether this also applies to children .
we decided to defer pacemaker therapy and instead opted for management of the tachyarrhythmia with catheter ablation .
ablation was preferred over medication because of potential concerns that an antiarrhythmic medication could lead to worsening of the bradycardia .
decision making was influenced by the fact that the patient was asymptomatic , with a normal cardiac structure and function on echocardiogram . while pacemaker placement would have been a permanent or semi - permanent intervention , ablation was preferred since it is a one - time procedure .
sinus pauses can occur in young patients with paroxysmal svt . based on this case ,
we recommend that initial treatment should be directed towards the svt and not to the bradyarrhythmia .
 sinus pauses in the setting of supraventricular tachycardia is rare in children . 
 we describe an asymptomatic teen with irregular heart rate detected during an incidental exam who was found to have short runs of a slow ectopic atrial tachycardia on electrocardiogram and prolonged sinus pauses on routine ambulatory ecg . 
 successful catheter ablation of the ectopic atrial tachycardia led to resolution of the sinus pauses . 
Introduction
Case report
Discussion
Conclusion
Author disclosures