title: Electrophysiologic assessment of conduction abnormalities and atrial arrhythmias associated with amyloid cardiomyopathy.
abstract: BACKGROUND
  Arrhythmias in cardiac amyloidosis (CA) result in significant comorbidity and mortality but have not been well characterized.
  
  
  OBJECTIVE
  The purpose of this study was to define intracardiac conduction, atrial arrhythmia substrate, and ablation outcomes in a group of advanced CA patients referred for electrophysiologic study.
  
  
  METHODS
  Electrophysiologic study with or without catheter ablation was performed in 18 CA patients. Findings and catheter ablation outcomes were compared to age- and gender-matched non-CA patients undergoing catheter ablation of persistent atrial fibrillation (AF).
  
  
  RESULTS
  Supraventricular tachycardias were seen in all 18 CA patients (1 AV nodal reentrant tachycardia, 17 persistent atrial tachycardia [AT]/AF). The HV interval was prolonged (>55 ms) in all CA patients, including 6 with normal QRS duration (≤100 ms). Thirteen supraventricular tachycardia ablations were performed in 11 patients. Of these, 7 underwent left atrial (LA) mapping and ablation for persistent AT/AF. Compared to non-CA age-matched comparator AF patients, CA patients had more extensive areas of low-voltage areas LA (63% ± 22% vs 34% ± 22%, P = .009) and a greater number of inducible ATs (3.3 ± 1.9 ATs vs 0.2 ± 0.4 ATs, P <.001). The recurrence rate for AT/AF 1 year after ablation was greater in CA patients (83% vs 25%), and the hazard ratio for postablation AT/AF recurrence in CA patients was 5.4 (95% confidence interval 1.9-35.5, P = .007).
  
  
  CONCLUSIONS
  In this group of patients with advanced CA and atrial arrhythmias, there was extensive conduction system disease and LA endocardial voltage abnormality. Catheter ablation persistent AT/AF in advanced CA was associated with a high recurrence rate and appears to have a limited role in control of these arrhythmias.
authors.affiliation: Leon H. Charney Division of Cardiology, New York University Langone Medical Center, New York, New York,. Electronic address: chirag.barbhaiya@nyumc.org.
authors.forename: Chirag R
authors.initials: CR
authors.lastname: Barbhaiya
authors.affiliation: Cardiovascular Division, Brigham and Women's Hospital, Boston, Massachusetts.
authors.forename: Saurabh
authors.initials: S
authors.lastname: Kumar
authors.affiliation: Cardiovascular Division, Brigham and Women's Hospital, Boston, Massachusetts.
authors.forename: Samuel H
authors.initials: SH
authors.lastname: Baldinger
authors.affiliation: Cardiovascular Division, Brigham and Women's Hospital, Boston, Massachusetts.
authors.forename: Gregory F
authors.initials: GF
authors.lastname: Michaud
authors.affiliation: Cardiovascular Division, Brigham and Women's Hospital, Boston, Massachusetts.
authors.forename: William G
authors.initials: WG
authors.lastname: Stevenson
authors.affiliation: Cardiovascular Division, Brigham and Women's Hospital, Boston, Massachusetts.
authors.forename: Rodney
authors.initials: R
authors.lastname: Falk
authors.affiliation: Cardiovascular Division, Brigham and Women's Hospital, Boston, Massachusetts.
authors.forename: Roy M
authors.initials: RM
authors.lastname: John
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D000686:Amyloidosis / Q000150:complications*; D001281:Atrial Fibrillation / Q000175:diagnosis / Q000503:physiopathology / Q000601:surgery; D009202:Cardiomyopathies / Q000150:complications*; D017115:Catheter Ablation / Q000379:methods*; D022062:Electrophysiologic Techniques, Cardiac / Q000379:methods; D005260:Female; D006325:Heart Atria / Q000473:pathology / Q000503:physiopathology; D006801:Humans; D008297:Male; D008875:Middle Aged; D017063:Outcome Assessment, Health Care; D012008:Recurrence; D013617:Tachycardia, Supraventricular / Q000175:diagnosis / Q000503:physiopathology
keywords: Ablation; Amyloidosis; Atrial fibrillation; Atrial flutter; Catheter ablation; Conduction; Electrophysiology