title: Paced ventricular electrogram fractionation predicts sudden cardiac death in hypertrophic cardiomyopathy.
abstract: OBJECTIVE
  Paced electrogram fractionation analysis (PEFA) has been assessed for the prediction of sudden cardiac death (SCD) in a large-scale, prospective study of patients with hypertrophic cardiomyopathy (HCM).
  
  
  RESULTS
  We determined the positive predictive value (PPV) of PEFA in relation to other risk factors for SCD and outcomes in 179 patients with HCM and no prior history of cardiac arrest. Patients were followed over a mean 4.3 years (range: 1.1-6.3 years). Thirteen patients had SCD-equivalent events: four of these patients died suddenly, three were resuscitated from ventricular fibrillation (VF), and six had implantable cardioverter-defibrillator (ICD) discharges in response to VF. PEFA identified nine of these patients and another 14 non-VF patients yielding a censored PPV of between 0.19 and 0.59 that was greater than the PPV that was the formal stopping point of the trial (0.18). Eighty per cent of patients were followed for 4 years or more. The PPV for the identification of SCD in this group was 0.38 (0.17-0.59). The use of two or more conventional markers to predict SCD identified five patients with SCD-equivalent events in the 4-year follow-up group and 42 other patients without events yielding a PPV of 0.106 (confidence limits 0.02-0.15).
  
  
  CONCLUSIONS
  PEFA identifies HCM patients at risk of SCD with greater accuracy than non-invasive techniques and may have an important role in determining indications for ICD prescription.
authors.affiliation: Department of Cardiology, Papworth Hospital, University of Cambridge, Cambridge CB23 3RE, UK.
authors.forename: Richard C
authors.initials: RC
authors.lastname: Saumarez
authors.forename: Mariusz
authors.initials: M
authors.lastname: Pytkowski
authors.forename: Maciej
authors.initials: M
authors.lastname: Sterlinski
authors.forename: John P
authors.initials: JP
authors.lastname: Bourke
authors.forename: Jonathan R
authors.initials: JR
authors.lastname: Clague
authors.forename: Stuart M
authors.initials: SM
authors.lastname: Cobbe
authors.forename: Derek T
authors.initials: DT
authors.lastname: Connelly
authors.forename: Michael J
authors.initials: MJ
authors.lastname: Griffith
authors.forename: Pascal P
authors.initials: PP
authors.lastname: McKeown
authors.forename: Karen
authors.initials: K
authors.lastname: McLeod
authors.forename: John M
authors.initials: JM
authors.lastname: Morgan
authors.forename: Nicolas
authors.initials: N
authors.lastname: Sadoul
authors.forename: Lidia
authors.initials: L
authors.lastname: Chojnowska
authors.forename: Christopher L-H
authors.initials: CL
authors.lastname: Huang
authors.forename: Andrew A
authors.initials: AA
authors.lastname: Grace
mesh_terms: D000293:Adolescent; D000328:Adult; D002304:Cardiac Pacing, Artificial; D002312:Cardiomyopathy, Hypertrophic / Q000401:mortality / Q000628:therapy*; D016757:Death, Sudden, Cardiac / Q000517:prevention & control*; D015716:Electrocardiography, Ambulatory; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D011446:Prospective Studies; D012372:ROC Curve; D018570:Risk Assessment; D012307:Risk Factors