title: Effects of the association of dual-site dynamic atrial overdrive and atenolol in preventing recurrent atrial fibrillation.
abstract: OBJECTIVE
  Evaluate the effects of optimized atrial stimulation--OAS (dual-site atrial pacing, heart rate above the intrinsic rate, and specific functional algorithm), and the use of atenolol in preventing recurrent atrial fibrillation (AF). Primary endpoint: to quantify the rate of AF episodes. Secondary endpoints: assessment of quality of life, specific cardiovascular symptoms, rate of hospital admissions, rate of electrical and pharmacological cardioversions, and adverse cardiac events.
  
  
  METHODS
  Twenty-five patients with recurrent episodes of paroxysmal AF and sinus node disease had dual-site atrial and ventricular pacemakers implanted, and were started on atenolol, 100 mg/day. Next, they were randomized to two groups: GROUP I: first three months with OAS and the specific pacing algorithm (DAO) turned on, and three more months with the algorithm off. GROUP II: the inverse sequence to GROUP I. The pacing mode chosen was DDDR, and after three months patients underwent clinical and electronic evaluations of the stimulation system by: automatic mode switch (AMS), 24-hour Holter monitoring, Doppler echocardiogram, and SF-36 questionnaire. Following, a crossover comparison took place, and a new assessment was performed six months later.
  
  
  RESULTS
  When compared to the group with the algorithm turned off, OAS patients had lower rates of: AF/week (p < 0.001); AMS activations (p < 0.01); hospitalizations (p < 0.001); cardioversions (p < 0.001), and higher scores on the physical and mental components of quality of life.
  
  
  CONCLUSIONS
  The hybrid therapy adopted, OAS associated with the use of atenolol, reduced the rate of recurrent AF and improved the clinical-functional status of patients with symptomatic bradyarrhythmias.
authors.affiliation: Hospital São Francisco de Assis.
authors.forename: Antonio da Silva
authors.initials: Ada S
authors.lastname: Menezes
authors.forename: Martino
authors.initials: M
authors.lastname: Martinelli Filho
authors.forename: Carlos Cléber dos Santos
authors.initials: CC
authors.lastname: Menezes
authors.forename: Roberto
authors.initials: R
authors.lastname: Costa
authors.forename: José Antônio Franchini
authors.initials: JA
authors.lastname: Ramires
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D000465:Algorithms; D000889:Anti-Arrhythmia Agents / Q000627:therapeutic use*; D001262:Atenolol / Q000627:therapeutic use*; D001281:Atrial Fibrillation / Q000517:prevention & control*; D002304:Cardiac Pacing, Artificial; D003131:Combined Modality Therapy; D018592:Cross-Over Studies; D004554:Electric Countershock; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D008297:Male; D008875:Middle Aged; D011446:Prospective Studies; D011788:Quality of Life; D055502:Secondary Prevention; D012804:Sick Sinus Syndrome / Q000628:therapy*; D016037:Single-Blind Method; D013997:Time Factors
chemical_list: D000889:Anti-Arrhythmia Agents; D001262:Atenolol