title: Left atrial volumes and associated stroke subtypes.
abstract: BACKGROUND
  Cardio embolism and cerebrovascular atherosclerosis are two major mechanisms of stroke. Studies investigating associations between advanced echocardiographic parameters and stroke mechanisms are limited.
  
  
  METHODS
  This study is a standardized review of 633 patients admitted to the stroke service of a tertiary care hospital following a standardized stroke investigation and management pathway. Stroke subtypes were characterized using the Causative Classification System, using the hospitals online radiologic archival system with CCS certified stroke investigators. Patients with two mechanisms were excluded.
  
  
  RESULTS
  Patients with cardioembolic stroke had a higher proportion of atrial fibrillation (p < 0.001), acute myocardial infarction (p < 0.001) and ischemic heart disease (p < 0.001). On electrocardiogram (ECG) and transthoracic Echo (TTE), patients with cardioembolic stroke had a greater atrial fibrillation (p < .00), left ventricular thrombus (p < .00), left ventricular ejection fraction <30% (p < .00) and global hypokinesia (p < .00) Patients with cardioembolic stroke had higher mean left atrial volume indices (LAVi) (p < 0.001), mean left ventricular mass indices (LVMi) (p < 0.05) and mean left atrial diameters (LAD) (p < 0.05). At LAVi of 29-33 ml/m2, the risk of atherothrombotic stroke increased. The risk of cardioembolic stroke increased with LAVi of 34 ml/m2 and above.
  
  
  CONCLUSIONS
  Left atrial volume indices may be linked to specific stroke phenotype. At mild increases in left atrial dimensions, the risks of atherosclerotic stroke are high, and probably reflect hypertension as the unifying mechanism. Further increases in left atrial dimensions shifts the risk towards cardioembolic stroke.
authors.forename: Quratulain
authors.initials: Q
authors.lastname: Shaikh
authors.forename: Bilal
authors.initials: B
authors.lastname: Ahmed
authors.forename: Maryam
authors.initials: M
authors.lastname: Ahmed
authors.forename: Jamal Hussain
authors.initials: JH
authors.lastname: Mahar
authors.forename: Masood
authors.initials: M
authors.lastname: Ahmad
authors.forename: Ayesha
authors.initials: A
authors.lastname: Ahmed
authors.forename: Farzin
authors.initials: F
authors.lastname: Majeed
authors.forename: Fariha Sadiq
authors.initials: FS
authors.lastname: Ali
authors.forename: Maria
authors.initials: M
authors.lastname: Khan
authors.affiliation: The International Cerebrovascular Translational Clinical Research Training Program, Stroke Services, Aga Khan University, Karachi, Pakistan. ayeesha.kamal@aku.edu.
authors.forename: Ayeesha Kamran
authors.initials: AK
authors.lastname: Kamal
mesh_terms: D004562:Electrocardiography / Q000379:methods; D006325:Heart Atria / Q000473:pathology* / Q000503:physiopathology; D006801:Humans; D020521:Stroke / Q000145:classification* / Q000175:diagnosis* / Q000503:physiopathology