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Permanent pacemaker upgrade.

We were interested to read the paper on pacemaker upgrade from Brandt et al. in Sweden. We were concerned, however, that they seem to be advocating routine upgrade of pacemakers from single to dual chamber at the time of elective generator change. Close inspection of their results does not bear out this policy. Of 34 patients in whom upgrade was attempted, one procedure failed due to arterial bleeding, three patients developed atrial lead malfunction and two patients did not leave hospital until the fourth postoperative day (reasons were not given). Six patients (18%) therefore had a less than straightforward peri-procedural course. As pointed out by Sutton, data on pacemaker upgrade — a procedure previously assumed to carry little risk — are sparse. Our recent report on 44 patients undergoing pacemaker upgrade, however, identified a significant incidence of complications. Gribbin et al. examined comparable