title: Microembolism and catheter ablation II: effects of cerebral microemboli injection in a canine model.
abstract: BACKGROUND
  Asymptomatic cerebral lesions have been observed on diffusion weighted MRI (DWI) scans shortly after catheter ablation of atrial fibrillation, but the pathogenesis of these lesions is incompletely understood.
  
  
  RESULTS
  Twelve dogs underwent selective catheterization of the internal carotid or vertebral arteries. Either a microbubbled mixture of air (1.0-4.0 mL), blood, contrast, and saline (n=5), or heat-dried pulverized blood (particle size <600 μm) mixed with saline and contrast (n=6) was injected. One sham control experiment was performed. MRI scans were performed preinjection, and at 1, 2, and 4 days postinjection. Neurological tests were performed daily. Gross pathology and histopathology were performed on the brains after being euthanized on day 4. Three animals died <24 hours after injection. Hyperintense lesions were observed on DWI (median maximum diameter 3.1 mm) in 2 of 4 animals after air embolism and in 3 of 5 animals after particulate embolism. No DWI lesions were detected in the remaining 5 animals (including the sham control). Lesions seen on DWI and confirmed on the fluid attenuating inversion recovery sequence correlated well with anatomic lesions on histopathology.
  
  
  CONCLUSIONS
  Cerebral embolization of air microbubbles or microparticulate debris that approximate the embolic sources from catheter ablation can create hyperintense DWI punctate lesions in a canine model. The location and size of the DWI/fluid attenuating inversion recovery lesions correlate with pathological findings.
authors.affiliation: Department of Cardiovascular Medicine, Oakland University William Beaumont School of Medicine, Royal Oak, MI 48073, USA. dhaines@beaumont.edu
authors.forename: David E
authors.initials: DE
authors.lastname: Haines
authors.forename: Mark T
authors.initials: MT
authors.lastname: Stewart
authors.forename: Noah D
authors.initials: ND
authors.lastname: Barka
authors.forename: Nicole
authors.initials: N
authors.lastname: Kirchhof
authors.forename: Linnea R
authors.initials: LR
authors.lastname: Lentz
authors.forename: Nicki M
authors.initials: NM
authors.lastname: Reinking
authors.forename: Jon F
authors.initials: JF
authors.lastname: Urban
authors.forename: Franck
authors.initials: F
authors.lastname: Halimi
authors.forename: Thomas
authors.initials: T
authors.lastname: Deneke
authors.forename: Emanuel
authors.initials: E
authors.lastname: Kanal
mesh_terms: D000818:Animals; D001522:Behavior, Animal; D062906:Cardiac Catheters; D002343:Carotid Artery, Internal; D017115:Catheter Ablation / Q000009:adverse effects* / Q000295:instrumentation; D002406:Catheterization, Peripheral; D002533:Cerebral Angiography; D038524:Diffusion Magnetic Resonance Imaging; D004195:Disease Models, Animal; D004285:Dogs; D004618:Embolism, Air / Q000209:etiology / Q000473:pathology / Q000503:physiopathology; D004867:Equipment Design; D020766:Intracranial Embolism / Q000209:etiology* / Q000473:pathology / Q000503:physiopathology; D009043:Motor Activity; D009460:Neurologic Examination; D013997:Time Factors; D014711:Vertebral Artery