title: Determinants of left atrial appendage volume in stroke patients without chronic atrial fibrillation.
abstract: BACKGROUND
  Left atrial appendage (LAA) volume has been shown to be increased in patients with acute cryptogenic stroke. Atrial fibrillation (AF) is a well-recognized risk factor but it is not the only one associated with LAA enlargement. The aim of the study was to clarify the multifactorial etiology of LAA enlargement in cardiogenic stroke/TIA patients without AF.
  
  
  METHODS
  Altogether 149 patients with suspected cardioembolic stroke/TIA (47 females; mean age 61 years) underwent cardiac CT. Diagnosed AF on admittance was an exclusion criteria but 24-hour Holter ambulatory ECG revealed paroxysmal AF (PAF) in 20 patients. Body surface area adjusted LAA volume was evaluated. Eighteen different variables were registered including general characteristics, definite and potential causal risk factors for ischemic stroke/TIA, clinical echoparameters and CT based cardiac volumetric and adipose tissue measurements. A stepwise linear regression analysis was performed to achieve a model adjusted for the number of predictors of LAA volume increase.
  
  
  RESULTS
  In linear regression analysis, the best model accounted for 30% of the variability in LAA volume, including PAF (19%) and enlarged left atrial volume (6%), enlarged left ventricle end-systolic diameter (3%) and decreased pericardial adipose tissue (2%). No multi-colinearity between variables was observed. In addition to PAF, no other definitive or potential causal risk factors could account for the LAA volume in these patients.
  
  
  CONCLUSIONS
  LAA volume increase seems to be poorly associated with currently known stroke/TIA risk factors, except for AF. Targeting more comprehensive ECG monitoring for stroke patients with increased LAA volume should be considered.
authors.affiliation: Department of Clinical Radiology, Kuopio University Hospital, Kuopio, Finland; Unit of Neurology, Institute of Clinical Medicine, University of Eastern Finland, Kuopio, Finland; Unit of Radiology, Institute of Clinical Medicine, University of Eastern Finland, Kuopio, Finland.
authors.forename: Mikko
authors.initials: M
authors.lastname: Taina
authors.affiliation: Department of Clinical Radiology, Kuopio University Hospital, Kuopio, Finland; Unit of Radiology, Institute of Clinical Medicine, University of Eastern Finland, Kuopio, Finland.
authors.forename: Petri
authors.initials: P
authors.lastname: Sipola
authors.affiliation: Department of Clinical Radiology, Kuopio University Hospital, Kuopio, Finland; Unit of Radiology, Institute of Clinical Medicine, University of Eastern Finland, Kuopio, Finland.
authors.forename: Antti
authors.initials: A
authors.lastname: Muuronen
authors.affiliation: Unit of Radiology, Institute of Clinical Medicine, University of Eastern Finland, Kuopio, Finland; Heart Center, Kuopio University Hospital, Kuopio, Finland.
authors.forename: Marja
authors.initials: M
authors.lastname: Hedman
authors.affiliation: Department of Cardiology, Keski-Suomi Central Hospital, Jyväskylä, Finland.
authors.forename: Pirjo
authors.initials: P
authors.lastname: Mustonen
authors.affiliation: Unit of Neurology, Institute of Clinical Medicine, University of Eastern Finland, Kuopio, Finland; NeuroCenter, Kuopio University Hospital, Kuopio, Finland.
authors.forename: Anne-Mari
authors.initials: AM
authors.lastname: Kantanen
authors.affiliation: Unit of Neurology, Institute of Clinical Medicine, University of Eastern Finland, Kuopio, Finland; NeuroCenter, Kuopio University Hospital, Kuopio, Finland.
authors.forename: Pekka
authors.initials: P
authors.lastname: Jäkälä
authors.affiliation: Department of Clinical Radiology, Kuopio University Hospital, Kuopio, Finland; Unit of Radiology, Institute of Clinical Medicine, University of Eastern Finland, Kuopio, Finland.
authors.forename: Ritva
authors.initials: R
authors.lastname: Vanninen
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D020517:Atrial Appendage / Q000473:pathology*; D001281:Atrial Fibrillation / Q000473:pathology*; D002908:Chronic Disease; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D012307:Risk Factors; D020521:Stroke / Q000209:etiology / Q000473:pathology*