The following is a summary of “Methylxanthine Derivatives in the Treatment of Sinus Node Dysfunction: A Systematic Review,” published in the November 2023 issue of Cardiology by Roth et al.
Despite their known ability to increase heart rate, theophylline and aminophylline’s effectiveness in treating sinus node dysfunction remains unclear. Researchers performed a retrospective study to assess the effectiveness and safety of methylxanthines for bradyarrhythmias linked to sinus node dysfunction.
The study was carried out following PRISMA guidelines. A comprehensive search was conducted on multiple databases, including Embase, PubMed, MEDLINE, Cochrane Central, Web of Science, SciELO, Korean Citation Index, Global Index Medicus, and CINAHL. Initially, 607 studies were identified through the literature search. After applying the inclusion and exclusion criteria, 14 studies were ultimately included in this review.
The result demonstrated Bradyarrhythmias involving the sinoatrial node had various causes, such as acute cervical spinal cord injury, COVID-19, carotid sinus syncope, chronotropic incompetence, heart transplant, and chronic sinus node dysfunction. Theophylline and aminophylline were effective in increasing heart rate and reducing bradyarrhythmia recurrence. The data on symptom resolution varied; while case studies reported symptom improvement, a randomized controlled trial found no significant difference in symptom scores among the control, theophylline, and pacemaker groups in treating sick sinus syndrome. Adverse effects (AEs) were infrequent across all study designs.
The study found that methylxanthines showed promise as a pharmacological alternative or bridge to pacemaker therapy for sinus node dysfunction-related bradyarrhythmias, though optimal dosing requires further investigation.
