title: Atrial standstill in sinus node disease due to extensive atrial fibrosis: impact on dual chamber pacemaker implantation.
abstract: OBJECTIVE
  Atrial standstill is characterized by the absence of atrial activity. We report about a series of cases, in which conventional atrial pacemaker lead implantation in patients with symptomatic sinus node disease failed due to lack of excitable right atrial tissue, thus, prompting the diagnosis of atrial standstill. We hypothesized that mapping of the atria with subsequent identification of myocardium still amenable to atrial pacing would allow dual chamber pacemaker implantation.
  
  
  RESULTS
  In four patients, atrial lead implantation failed. In these patients, spontaneous or fibrillatory electrical activity was absent but the atria could not be captured despite high stimulation voltages at conventional atrial sites. We suspected partial or complete atrial standstill and subsequently confirmed this hypothesis by conventional (n = 1) or electroanatomical mapping (n = 3). Areas of fibrotic tissue were present in all patients as identified by lack of spontaneous electrical activity and inability of local electrical capture via the mapping catheter. Surviving atrial tissue, which could be electrically captured with subsequent conduction of activity to the atrioventricular (AV) node, was present in three patients. Successful targeted atrial lead implantation at these sites was achieved in all these patients. Isolated sinus node activity without conduction to the atria was found in one patient.
  
  
  CONCLUSIONS
  Partial atrial standstill may be present and prevent atrial lead implantation in patients with sinus node disease. In these patients, recognition of partial atrial standstill and identification of surviving muscular islets with connection to the AV node by mapping studies may still allow synchronous AV sequential pacing.
authors.affiliation: Department of Cardiology, Charité Berlin Campus Benjamin Franklin, Hindenburgdamm 30, 12203 Berlin, Germany Department of Cardiology, University Hospital, Technical University Aachen RWTH, Pauwelstrasse 30, 52074 Aachen, Germany barbara.bellmann@charite.de.
authors.forename: Barbara
authors.initials: B
authors.lastname: Bellmann
authors.affiliation: Department of Cardiology, Charité Berlin Campus Benjamin Franklin, Hindenburgdamm 30, 12203 Berlin, Germany.
authors.forename: Mattias
authors.initials: M
authors.lastname: Roser
authors.affiliation: Department of Cardiology, Charité Berlin Campus Benjamin Franklin, Hindenburgdamm 30, 12203 Berlin, Germany.
authors.forename: Bogdan
authors.initials: B
authors.lastname: Muntean
authors.affiliation: Department of Cardiology, Charité Berlin Campus Benjamin Franklin, Hindenburgdamm 30, 12203 Berlin, Germany.
authors.forename: Verena
authors.initials: V
authors.lastname: Tscholl
authors.affiliation: Department of Cardiology, Charité Berlin Campus Benjamin Franklin, Hindenburgdamm 30, 12203 Berlin, Germany.
authors.forename: Patrick
authors.initials: P
authors.lastname: Nagel
authors.affiliation: Department of Cardiology, University Hospital, Technical University Aachen RWTH, Pauwelstrasse 30, 52074 Aachen, Germany.
authors.forename: Michael
authors.initials: M
authors.lastname: Schmid
authors.affiliation: Department of Cardiology, University Hospital, Technical University Aachen RWTH, Pauwelstrasse 30, 52074 Aachen, Germany Kardiologie an der Rudower Chaussee, Rudower Chausee 9, 12489 Berlin, Germany.
authors.forename: Patrick
authors.initials: P
authors.lastname: Schauerte
mesh_terms: D000328:Adult; D000368:Aged; D016279:Atrial Function, Left; D016280:Atrial Function, Right; D064752:Atrial Remodeling; D002304:Cardiac Pacing, Artificial; D015150:Echocardiography, Doppler; D015716:Electrocardiography, Ambulatory; D022062:Electrophysiologic Techniques, Cardiac; D004867:Equipment Design; D005260:Female; D005355:Fibrosis; D006325:Heart Atria / Q000473:pathology / Q000503:physiopathology; D006801:Humans; D008297:Male; D008875:Middle Aged; D010138:Pacemaker, Artificial; D012804:Sick Sinus Syndrome / Q000175:diagnosis / Q000503:physiopathology / Q000628:therapy*; D012849:Sinoatrial Node / Q000503:physiopathology*; D013997:Time Factors; D014022:Tissue Survival; D016896:Treatment Outcome
keywords: Atrial mapping; Atrial standstill; Pacemaker; Sinus node