Long sinus pause on ECG rhythm strip

Long sinus pause on ECG rhythm strip


Long Sinus Pause

Long Sinus Pause on Holter ECG

ECG rhythm strip documenting a long sinus pause of around 8.5 seconds. Such long pauses would indicate suppression of sinus node activity and is a manifestation of sick sinus syndrome.

Pauses more than 3 seconds while awake, would indicate implantation of a permanent pacemaker, provided reversible causes can be ruled out. Occasionally long pauses can occur during sleep, which need not have the same significance as pauses which occur while awake. Pauses during sleep can be recognized only by continuous monitoring by either Holter or event recorders.

Long pauses can occur during termination of a tachyarrhythmia, classically after termination of atrial fibrillation in a tachy-brady syndrome. This is because of down regulation of pacemaker current (If current, also known as funny current) by the prolonged tachycardia. That is why pauses on termination of tachycardias do not have the same weightage as spontaneous pauses regarding indication for permanent pacemaker implantation. Some such pauses may not recur after ablation of the tachycardia focus.

In a case report, a teenager with paroxysmal ectopic atrial tachycardia with long sinus pauses was presented [1]. Longest pause was 5s and the pauses were mostly, but not always, associated with termination of the tachycardia. Electrophysiology study showed ectopic atrial tachycardia originating from the right atrial appendage. There was no bradycardia or sinus pause documented in a Holter done one week after catheter ablation of the ectopic atrial tachycardia.

Long sinus pauses due to autonomic dysfunction has been reported in a case of temporal lobe epilepsy [2]. Ten second sinus pause about 20 seconds after seizure onset was documented in this patient. Patient underwent DDD pacemaker implantation.

In another interesting case, carotid sinus syndrome with recurrent sinus pauses with syncope due to a massive multinodular goiter was reported [3]. There was no recurrence of bradycardia after an uneventful total thyroidectomy.

References

  1. Balaji S. Management of paroxysmal ectopic atrial tachycardia with long sinus pauses in a teenager. Indian Pacing Electrophysiol J. 2016 Feb 12;15(5):249-50. doi: 10.1016/j.ipej.2016.02.003. PMID: 27134442; PMCID: PMC4834423.
  2. Amor MM, Eltawansy SA, Osofsky J, Holland N. Recurrent sinus pauses: an atypical presentation of temporal lobe epilepsy. Case Rep Crit Care. 2014;2014:918247. doi: 10.1155/2014/918247. Epub 2014 Sep 28. PMID: 25328719; PMCID: PMC4195260.
  3. Deshmukh A, Ozcan C. Symptomatic Long Pauses and Bradycardia due to Massive Multinodular Goiter. Case Rep Cardiol. 2017;2017:4201942. doi: 10.1155/2017/4201942. Epub 2017 Aug 6. PMID: 28845312; PMCID: PMC5563397.