When are “pauses” reported on Holter a concern?
Pauses of up to 2 seconds are common in the general population and are especially common in the elderly. These pauses are usually benign. The most frequent causes of pauses are blocked (non-conducted) premature atrial contractions (PACs), sinus arrhythmia, temporary pauses in the rate of discharge of the sinoatrial node (i.e., sinus pauses) and medication-induced pauses.
Pauses of longer than 2 seconds, especially when frequent and accompanied by episodes of significant bradycardia (less than 40 beats per minute), suggest the possibility of sick sinus syndrome.
Longer pauses (3 seconds or greater) are more likely to be symptomatic and pathologic. Pacemaker implantation should be considered if there are symptoms of syncope, dizziness, or severe fatigue in association with prolonged pauses (i.e. 3 seconds or more) or with persistent bradycardia.
Grauer K, Leytem B. A systematic approach to Holter monitor interpretation. Am Fam Physician. 1992 Apr;45(4):1641-8