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Prospective randomized study of mode switching in a clinical trial of pacemaker therapy for sinus node dysfunction
Michael O Sweeney1, Anne S Hellkamp, Kenneth A Ellenbogen
1Brigham and Women's Hospital and Harvard Medical School, Boston, Massachusetts 02115, USA. mosweeney@partners.org
Journal of Cardiovascular Electrophysiology
|March 19, 2004
Summary
Mode switching (MS) in DDDR pacemakers reduces pacemaker reprogramming due to rapid ventricular pacing (RVP) during atrial high-rate episodes (AHREs) in patients with sinus node dysfunction (SND). However, MS did not improve quality of life or cardiovascular symptoms.
Area of Science:
- Cardiology
- Biomedical Engineering
- Clinical Electrophysiology
Background:
- Atrial fibrillation (AF) is prevalent in pacemaker patients with sinus node dysfunction (SND).
- Rapid ventricular pacing (RVP) can occur in DDDR mode pacing during AF.
- The clinical utility of mode switching (MS) to mitigate RVP in SND patients remains unclear.
Purpose of the Study:
- To evaluate the clinical benefit of mode switching (MS) in patients with sinus node dysfunction (SND) experiencing atrial high-rate episodes (AHREs).
- To assess the impact of MS on cardiovascular symptoms, quality of life, and pacemaker reprogramming in DDDR-paced SND patients.
Main Methods:
- A subrandomization of 202 patients from the Mode Selection Trial (MOST) compared MS ON versus MS OFF in DDDR-paced SND patients.
- Outcomes assessed included cardiovascular symptoms, quality of life (QOL), and pacemaker reprogramming due to RVP during AHREs.
- Median follow-up was 2.2 years, with analysis of AHRE characteristics and clinical events.
Main Results:
- Mode switching (MS) significantly reduced pacemaker reprogramming due to RVP during AHREs (3.1% vs 13.2%, P=0.011).
- No significant differences were observed in the frequency, duration, or time spent in AHREs between MS ON and MS OFF groups.
- Cardiovascular symptoms, quality of life, death, stroke, and heart failure hospitalizations were similar between the two groups.
Conclusions:
- Mode switching (MS) effectively reduces pacemaker reprogramming related to RVP in SND patients with AHREs.
- Despite reducing reprogramming, MS did not demonstrate significant improvements in overall quality of life or cardiovascular symptoms in this patient cohort.
