title: A study of implanted cardiac rhythm recorders in advanced cardiac AL amyloidosis.
abstract: OBJECTIVE
  AL amyloidosis may respond to chemotherapy but two-thirds of patients with severe cardiac involvement die within a year of diagnosis, purportedly from tachyarrhythmias or electromechanical dissociation. We sought to characterize the nature of cardiac arrhythmias in severe cardiac AL amyloidosis using implanted cardiac rhythm recorders.
  
  
  RESULTS
  Implantable loop recorders (ILRs) were inserted within 24 h of baseline evaluation at the UK National Amyloidosis Centre, into 20 consecutive patients with newly diagnosed severe cardiac AL amyloidosis and symptoms of syncope or pre-syncope. Weekly ILR recordings and additional recordings at the time of symptoms were obtained. Median (range) follow-up from baseline was 308 (10-399) days. Thirteen patients died, and median survival in the whole cohort was 61 days from device insertion. In each of eight evaluable cases, death was heralded by bradycardia, usually associated with complete atrioventricular block (CAVB), followed shortly thereafter by pulseless electrical activity. Four patients received pacemakers, a median (range) of 7 (3-38) h after development of symptomatic CAVB, but these did not prevent rapid cardiac decompensation and death in three cases. Despite 272 loop recordings, there was only one episode of non-sustained ventricular tachycardia, which was preceded by severe bradycardia. Patients who died had significantly worse global left ventricular strain on echocardiography (P = 0.029) and reduced 6 min walk distance (P = 0.048) at baseline compared with survivors.
  
  
  CONCLUSIONS
  The discovery that bradyarrhythmias heralded terminal cardiac decompensation in most patients with severe cardiac AL amyloidosis supports a study of prophylactic pacemaker insertion in this patient population.
authors.affiliation: National Amyloidosis Centre, Division of Medicine, University College London, Royal Free Campus, Rowland Hill Street, London NW3 2PF, UK.
authors.forename: Rabya H
authors.initials: RH
authors.lastname: Sayed
authors.affiliation: Department of Cardiology, Royal Free London NHS Foundation Trust, London, UK.
authors.forename: Dominic
authors.initials: D
authors.lastname: Rogers
authors.affiliation: Department of Cardiology, Royal Free London NHS Foundation Trust, London, UK.
authors.forename: Fakhar
authors.initials: F
authors.lastname: Khan
authors.affiliation: National Amyloidosis Centre, Division of Medicine, University College London, Royal Free Campus, Rowland Hill Street, London NW3 2PF, UK.
authors.forename: Ashutosh D
authors.initials: AD
authors.lastname: Wechalekar
authors.affiliation: National Amyloidosis Centre, Division of Medicine, University College London, Royal Free Campus, Rowland Hill Street, London NW3 2PF, UK.
authors.forename: Helen J
authors.initials: HJ
authors.lastname: Lachmann
authors.affiliation: National Amyloidosis Centre, Division of Medicine, University College London, Royal Free Campus, Rowland Hill Street, London NW3 2PF, UK.
authors.forename: Marianna
authors.initials: M
authors.lastname: Fontana
authors.affiliation: National Amyloidosis Centre, Division of Medicine, University College London, Royal Free Campus, Rowland Hill Street, London NW3 2PF, UK.
authors.forename: Shameem
authors.initials: S
authors.lastname: Mahmood
authors.affiliation: National Amyloidosis Centre, Division of Medicine, University College London, Royal Free Campus, Rowland Hill Street, London NW3 2PF, UK.
authors.forename: Sajitha
authors.initials: S
authors.lastname: Sachchithanantham
authors.affiliation: National Amyloidosis Centre, Division of Medicine, University College London, Royal Free Campus, Rowland Hill Street, London NW3 2PF, UK.
authors.forename: Ketna
authors.initials: K
authors.lastname: Patel
authors.affiliation: National Amyloidosis Centre, Division of Medicine, University College London, Royal Free Campus, Rowland Hill Street, London NW3 2PF, UK.
authors.forename: Philip N
authors.initials: PN
authors.lastname: Hawkins
authors.affiliation: National Amyloidosis Centre, Division of Medicine, University College London, Royal Free Campus, Rowland Hill Street, London NW3 2PF, UK Department of Cardiology, Royal Free London NHS Foundation Trust, London, UK.
authors.forename: Carol J
authors.initials: CJ
authors.lastname: Whelan
authors.affiliation: National Amyloidosis Centre, Division of Medicine, University College London, Royal Free Campus, Rowland Hill Street, London NW3 2PF, UK j.gillmore@ucl.ac.uk.
authors.forename: Julian D
authors.initials: JD
authors.lastname: Gillmore
mesh_terms: D000328:Adult; D000368:Aged; D000686:Amyloidosis / Q000150:complications*; D000889:Anti-Arrhythmia Agents / Q000627:therapeutic use; D001145:Arrhythmias, Cardiac / Q000175:diagnosis* / Q000188:drug therapy / Q000209:etiology; D009202:Cardiomyopathies / Q000150:complications*; D003625:Data Collection; D015716:Electrocardiography, Ambulatory / Q000295:instrumentation; D004567:Electrodes, Implanted; D005260:Female; D006323:Heart Arrest / Q000209:etiology; D006801:Humans; D008297:Male; D008875:Middle Aged; D011379:Prognosis
chemical_list: D000889:Anti-Arrhythmia Agents
keywords: Amyloidosis; Bradycardia; Cardiomyopathy; Implantable loop recorder