title: The association of atrial tachyarrhythmias with isolated atrial amyloid disease: preliminary observations in autopsied heart specimens.
abstract: OBJECTIVE
  Isolated atrial amyloidosis (IAA) is associated with atrial tachyarrhythmias. However, only a few studies have appraised atrial tachyarrhythmias and atrial depolarization abnormalities in connection with high-grade IAA. We conducted a collaborative retrospective study to assess this association.
  
  
  METHODS
  One hundred consecutive autopsied hearts were studied histologically for IAA. To increase the specificity for atrial depolarization abnormalities in this preliminary study, we excluded those specimens with intermediate amyloid involvement, i.e. IAA grades 1 and 2 (grade 0 = absent or trivial deposits; grade 1 = small deposits; grade 2 = moderate deposits; grade 3 = dense, large deposits). We then screened for baseline, premortem electrocardiograms (ECGs) to assess rhythm. In those with sinus rhythm, the P wave axis, duration, dispersion and terminal force in V1 were determined under magnification.
  
  
  RESULTS
  Of the 27 premortem ECGs corresponding to the autopsy specimens with grades 3 (sample) or 0 (controls) IAA, 9 showed sinus rhythm, 13 showed atrial fibrillation, 1 showed atrial flutter and 4 were uninterpretable. Fourteen autopsied hearts (52%) were positive for grade 3 IAA. Ten of those had atrial tachyarrhythmias (9 atrial fibrillation and 1 atrial flutter) compared to 4 of the 13 hearts with grade 0 IAA (72 vs. 31%, respectively; p = 0.03). Although there was excellent interobserver agreement using intraclass correlation coefficients, there were no significant differences in P wave measurements among the small number of patients with sinus rhythm for grade 3 versus grade 0 IAA.
  
  
  CONCLUSIONS
  In a collaborative, preliminary, pilot assessment of autopsied hearts for which premortem ECGs were necessarily screened retrospectively, significantly more hearts with high-grade IAA were associated with atrial tachyarrhythmias compared to those with low-grade IAA. A larger study with an appropriately matched autopsy control group is needed to confirm these and previous observations.
authors.affiliation: Division of Cardiology, Department of Medicine, St. Boniface General Hospital, University of Manitoba, Winnipeg, MB, Canada. vignendra@hotmail.com
authors.forename: Vignendra
authors.initials: V
authors.lastname: Ariyarajah
authors.forename: Ivo
authors.initials: I
authors.lastname: Steiner
authors.forename: Petra
authors.initials: P
authors.lastname: Hájková
authors.forename: Aliasghar
authors.initials: A
authors.lastname: Khadem
authors.forename: Jiri
authors.initials: J
authors.lastname: Kvasnicka
authors.forename: Sirin
authors.initials: S
authors.lastname: Apiyasawat
authors.forename: David H
authors.initials: DH
authors.lastname: Spodick
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D000686:Amyloidosis / Q000453:epidemiology* / Q000473:pathology*; D001344:Autopsy; D005260:Female; D006325:Heart Atria / Q000473:pathology; D006801:Humans; D008297:Male; D008875:Middle Aged; D009206:Myocardium / Q000473:pathology*; D010865:Pilot Projects; D012189:Retrospective Studies; D012307:Risk Factors; D013612:Tachycardia, Ectopic Atrial / Q000453:epidemiology* / Q000473:pathology*