RESUMO
We examined the hypothesis that a greater than or equal to 2 second pause detected on 24-hour Holter monitoring in patients with persistent atrial fibrillation and complaints of syncope or dizziness lacked sufficient specificity to warrant implantation of a permanent pacemaker. We retrospectively reviewed cases from our 24-hour electrocardiographic (Holter) monitoring data base. A total of 411 consecutive Holter monitoring records demonstrating persistent atrial fibrillation obtained during a 5-year period (1982 to 1987) were examined. One hundred and five (26%) patients had cerebral symptoms (dizziness or syncope) as a primary indication for monitoring 80 (76%) patients were identified with documented ventricular pauses of greater than or equal to 2 seconds. Three hundred and six patients (74%) underwent 24-hour monitoring without cerebral symptoms as an indication and 209 (68%) patients had greater than or equal to 2-second pauses. Clinical information was available in 164 (50 symptomatic and 114 asymptomatic) patients. There were no significant differences in the clinical or Holter findings between the two groups. Of the 50 symptomatic patients, 15 (30%) underwent permanent pacemaker placement and the remaining 35 (70%) were managed conservatively during a mean follow-up of 23 +/- 5 months. Eleven of 15 paced (73%) and 31 of 35 (89%) nonpaced patients experienced resolution of their cerebral symptoms (NS). The sensitivity of Holter monitoring in detecting pauses of greater than or equal to 2 seconds in patients with cerebral symptoms was high (76%), but the specificity (32%) and positive predictive values (28%) were low.(ABSTRACT TRUNCATED AT 250 WORDS)