Safety and comfort of patients mobilized 24 and 48 hours after a pacemaker implantation: a retrospective study. Background. In Italy bed rest times after a pacemaker implantation (PI) may vary between 24 and 72 hours, although previous studies showed that early mobilization does not increase the risk of complications. Objective. To observe the safety and comfort of mobilization 24 and 48 hours after PI. Methods. Observational retrospective study on clinical records of consecutive patients undergoing PI from January 2009 to April 2012 in Monzino Hospital in Milan and with a bed rest of 24 or 48 hours. Results. A total of 411 patients were included (Group 48h n=251, Group 24h: n=160). Complications occurred more frequently in the Group 48h: haematomas (3.2% vs 1.9% OR:1.71, p=0.4269); lead dislocations (1.9% vs. 0.6%; OR:3.23 p=0.2863). Patients with longer bed rest received more analgesics for back pain (BP) or pacemaker pocket pain (PPP) (BP: 12% vs 3.1%; OR:4.21; p=0.0036; PPP 13.1% vs 3.7% OR:3.88; p=0.0029). Conclusions. The mobilization after 24 hours to PI increased patients' comfort without increasing risks. Future studies are warranted to explore the effects of a bed rest shorter than 24 hours.