Seasonal distribution of pacemaker implantation for symptomatic bradycardia.

Permanent cardiac-pacemaker therapy is widely recognized as beneficial in the treatment of various types of symptomatic bradycardia. However, the seasonal distribution of pacemaker implantation has never been discussed. The purpose of this study was to investigate the seasonal distribution of pacemaker implantation in a large population of patients with symptomatic bradycardia. The study population consisted of 904 patients who underwent implantation of a new permanent pacemaker between January 1999 and December 2001 and were registered in the database of CPI Company in Taiwan. The number of pacemaker implantations in each month was analyzed to investigate the seasonal distribution of pacemaker implantations in a year. The number of patients who underwent pacemaker implantation between October and December was significantly higher than that of other seasons (P < 0.007). The results indicate that there is a tendency for bradyarrhythmic patients to have symptoms between October and December.