title: [Effects of myocardial stretching on excitation frequencies determined by spectral analysis during ventricular fibrillation].
abstract: OBJECTIVE
  The aim of this study was to analyze the effects of myocardial stretching on excitation frequencies, as determined by spectral analysis, during ventricular fibrillation.
  
  
  METHODS
  In 12 isolated rabbit heart preparations, ventricular activation during ventricular fibrillation was recorded with multiple electrodes. Recordings were obtained before, during and after ventricular dilatation produced with an intraventricular balloon. The dominant frequency of the signals obtained with each of the electrodes was determined by spectral analysis.
  
  
  RESULTS
  During the control phase, the mean, minimum and maximum dominant frequencies were, respectively, 14.3 1.7, 12.5 1.7, and 16.2 1.4 Hz, and the average difference between the maximum and minimum frequencies was 3.6 2.1 Hz. This difference was over 4 Hz in four cases, and in no case did it exceed 8 Hz. During ventricular stretching, the mean dominant frequency increased significantly (21.1 6.1 Hz; p < 0.0001), as did the minimum values (14 2.6 Hz; p < 0.05) and especially the maximum values (26.6 7.7 Hz; p < 0.0001). The difference between the maximum and minimum frequencies (12.6 6.4 Hz; p < 0.001) was over 4 Hz in all cases except one, and over 8 Hz in 9 cases. The maximum values were distributed heterogeneously during ventricular stretching. Upon suppressing ventricular stretching, the dominant frequency did not differ from controls.
  
  
  CONCLUSIONS
  Myocardial frequency maps during ventricular fibrillation show limited variations in the dominant frequency of the signals recorded in the lateral wall of the left ventricle. During stretching, the patterns were heterogeneous, due mainly to the marked increase in the maximum dominant frequency. In the experimental model used, the effects of stretching remitted after suppressing ventricular dilatation.
authors.affiliation: Servicio de Cardiología del Hospital Clínico Universitario de Valencia. España. francisco.j.chorro@uv.es
authors.forename: Francisco J
authors.initials: FJ
authors.lastname: Chorro
authors.forename: José
authors.initials: J
authors.lastname: Millet
authors.forename: Angel
authors.initials: A
authors.lastname: Ferrero
authors.forename: Antonio
authors.initials: A
authors.lastname: Cebrián
authors.forename: Joaquín
authors.initials: J
authors.lastname: Cánoves
authors.forename: Alvaro
authors.initials: A
authors.lastname: Martínez
authors.forename: Luis
authors.initials: L
authors.lastname: Mainar
authors.forename: Juan Carlos
authors.initials: JC
authors.lastname: Porres
authors.forename: Juan
authors.initials: J
authors.lastname: Sanchis
authors.forename: Vicente
authors.initials: V
authors.lastname: López Merino
authors.forename: Luis
authors.initials: L
authors.lastname: Such
mesh_terms: D000818:Animals; D004594:Electrophysiology; D006321:Heart / Q000503:physiopathology*; D066298:In Vitro Techniques; D009206:Myocardium; D011817:Rabbits; D014693:Ventricular Fibrillation / Q000503:physiopathology*