title: Same morphology of ventricular premature complexes triggering repeated ventricular fibrillation.
abstract: BACKGROUND
  Episodes ventricular fibrillation (VF) initiated by ventricular premature complexes (VPCs) of a single morphology have been reported. However, the characteristics of the VPCs over long periods of time are unknown.
  
  
  OBJECTIVE
  To compare the morphologies and coupling intervals of VPCs that initiate episodes of VF that occur at different time periods.
  
  
  METHODS
  The database of the follow-up of the International Classification of Diseases (ICD) unit was reviewed and patients having at least two spontaneous VF episodes with available recorded EGMs in unipolar and bipolar configuration were included in the study. The coupling interval and morphology of the initiating beat were analyzed.
  
  
  RESULTS
  Nine out of 300 patients with ICD had two or more spontaneous VF episodes. The time interval between episodes ranged from seconds (arrhythmic storm) to 3 years. The fibrillatory VPCs presented the same morphology in both recordings in all episodes of each patient. The coupling intervals of VPCs initiating VF were close for the episodes that occurred during a single arrhythmic storm and were more variable when the time intervals between episodes of VF were longer.
  
  
  CONCLUSIONS
  VPCs triggering VF that occur at different times in the same patient have similar morphologies suggesting similar sites of origin for the initial VPC of VF in each patient.
authors.affiliation: Arrhythmia Unit, University Hospital Virgen de la Arrixaca, Murcia, Ctra. Madrid-Cartagena, 30120, El Palmar, Murcia, Spain. juanjosanchezmunoz@me.com
authors.forename: Juan José
authors.initials: JJ
authors.lastname: Sánchez-Muñoz
authors.forename: Arcadio
authors.initials: A
authors.lastname: García-Alberola
authors.forename: Juan
authors.initials: J
authors.lastname: Martínez-Sánchez
authors.forename: Pablo
authors.initials: P
authors.lastname: Peñafiel-Verdú
authors.forename: César
authors.initials: C
authors.lastname: Caro-Martínez
authors.forename: Sergio
authors.initials: S
authors.lastname: Manzano-Fernández
authors.forename: Mariano
authors.initials: M
authors.lastname: Valdés-Chavarri
mesh_terms: D000328:Adult; D000368:Aged; D017147:Defibrillators, Implantable; D004562:Electrocardiography; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D014693:Ventricular Fibrillation / Q000209:etiology* / Q000503:physiopathology* / Q000517:prevention & control; D018879:Ventricular Premature Complexes / Q000150:complications* / Q000503:physiopathology* / Q000517:prevention & control