Single Chamber Atrial Leadless Pacing for Isolated Sinus Node Dysfunction

• Implantable Loop Recorder (Device): Implantation of a loop recorder in subjects with sick sinus syndrome and normal atrioventricular conduction who are receiving an atrial leadless pacemaker as standard of care.

Primary outcomes

• Incidence of atrial fibrillation [24 months]: Incidence of atrial fibrillation in patients implanted with a single chamber (Aveir AR, Abbott) leadless pacemaker and a loop recorder.

Secondary outcomes

• Composite incidence of a newly prolonged PR interval [24 months]: Composite incidence of a newly prolonged PR interval >/= 300ms or a need for system upgrade from a single chamber (Aveir AR, Abbott) leadless pacemaker to a dual chamber leadless pacemaker (Aveir DR, Abbott) at two-years
• Need for system upgrade from a single chamber to dual chamber [24 months]: Need for system upgrade from a single chamber (Aveir AR, Abbott) leadless pacemaker to a dual chamber leadless pacemaker (Aveir DR, Abbott) at two-years.
• Battery Longevity [24 months]: Remaining battery longevity of the single chamber leadless atrial pacemaker (Aveir, AR) compared with remaining battery longevity of subjects in the Aveir DR i2i study implanted with a dual chamber leadless pacemaker with comparable percentages of atrial pacing without ventricular pacing.

Sex: All, ages: 18 Years to any

Inclusion Criteria:

1. Symptomatic sinus bradycardia
2. Sino-atrial exit block
3. Symptomatic sinus arrest with sinus pauses > 2 sec during waking hours
4. Symptomatic sinus bradycardia < 40 bpm for > 1 min during waking hours
5. PR interval ≤ 0.22 sec if aged < 70 years or PR interval ≤ 0.26 sec if aged ≥ 70 years
6. QRS width ≤ 0.12 sec
7. No prior PM implantation
8. Patients willing to receive an Assert-IQ loop recorder for research purposes

Exclusion Criteria:

1. Atrioventricular block
2. Bundle branch block
3. History of atrial fibrillation
4. Carotid sinus hypersensitivity
5. Planned cardiac surgery
6. Estimated life expectancy < 1 year
7. Presence of an existing ventricular pacemaker or implantable cardioverter defibrillator
8. Known acute deep vein thrombosis of either lower extremity
9. Unable to read or write
10. Patient with Limited English Proficiency (LEP)
11. Cognitively impaired individuals
12. Pregnant

• James Gabriels, MD, Principal investigator, Northwell Health