Twins with implanted pacemakers: Is there an increased mortality risk for the co-twin? A follow-up study based on the Danish Twin Registry and the Danish Pacemaker Register.

Journal Article


The main indications for implanting a cardiac pacemaker are either acquired atrio-ventricular block (AVB) or sick sinus syndrome (SSS). In general, the exact aetiology of these conditions is unknown. Genetic factors may play a role. Untreated AVB is associated with increased mortality but SSS seems to have a good prognosis. The present study was designed to assess whether first-degree relatives of these patients have an increased mortality risk.


We investigated the survival pattern of the co-twins of twins who have had a cardiac pacemaker implanted, by linking two nationwide registries in Denmark: the Danish Pacemaker Register and the Danish Twin Registry. For each "pacemaker-twin" four control-twins matched with respect to age, sex, and zygosity were selected among the twins who were alive at the time of the pacemaker implantation. A total of 159 twins with a pacemaker treated bradycardia of unknown aetiology were identified of which 73 had AVB and 64 had SSS. A total of 622 matched control-twins could be identified. The survival from age six of the co-twins of the "pacemaker-twins" was compared with that of the co-twins of the control-twins. The follow-up period ended January 1st, 2000.


The survival curves for the co-twins of the "pacemaker-twins" were virtually identical to those of the co-twins of the control-twins. This finding was consistent for both AVB and SSS and for monozygotic as well as dizygotic twins.


No increased mortality risk could be demonstrated for first-degree relatives--including monozygotic twins--of patients with a cardiac pacemaker implanted due to either acquired AVB or SSS.

Full Text

Duke Authors

Cited Authors

  • Tveskov, C; Skytthe, A; Arnsbo, P; Vaupel, JW; Møller, M; Christensen, K

Published Date

  • November 2005

Published In

Volume / Issue

  • 7 / 6

Start / End Page

  • 598 - 603

PubMed ID

  • 16216763

Pubmed Central ID

  • 16216763

Electronic International Standard Serial Number (EISSN)

  • 1532-2092

International Standard Serial Number (ISSN)

  • 1099-5129

Digital Object Identifier (DOI)

  • 10.1016/j.eupc.2005.07.003


  • eng