Spectral analysis of intracardiac electrograms during induced and spontaneous ventricular fibrillation in humans.
OBJECTIVE
Very limited data are available on the differences between spontaneous and induced episodes of ventricular fibrillation (VF) in humans. The aim of the study was to compare the spectral characteristics of the electrical signal recorded by an implantable cardioverter defibrillator (ICD) during both types of episodes.


RESULTS
Thirteen ICD patients with at least one spontaneous and one induced VF recorded by the device were included in the study. A spectral representation was obtained for the first 3 s of the intracardiac unipolar electrogram during VF. The dominant frequency (f(d)), the peak power at f(d), an organization index (OI), a bandwidth measurement, and an estimate of the correlation with a sinusoidal wave (leakage) were estimated for each episode. The f(d) was higher in induced episodes (4.75 +/- 0.57 vs. 3.95 +/- 0.59 Hz for the spontaneous episodes, P = 0.002), as well as the degree of organization assessed by the OI, bandwidth, and leakage parameters.


CONCLUSIONS
Clinical and induced VF episodes in humans have different spectral characteristics. Changes in the electrophysiological substrate or in the location of the arrhythmia wavefront at onset could play a role to explain the observed differences.
Sánchez-Muñoz
Juan José
JJ
Arrhythmia Unit, Hospital Universitario Virgen de la Arrixaca de Murcia, El Palmar, Murcia 30120, Spain. jjsanchezmunoz@gmail.com
Rojo-Alvarez
José Luis
JL
García-Alberola
Arcadi
A
Everss
Estrella
E
Alonso-Atienza
Felipe
F
Ortiz
Mercedes
M
Martínez-Sánchez
Juan
J
Ramos-López
Javier
J
Valdés-Chavarri
Mariano
M
D017147:Defibrillators, Implantable; D003936:Diagnosis, Computer-Assisted / Q000379:methods*; D004562:Electrocardiography / Q000379:methods*; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity; D014693:Ventricular Fibrillation / Q000175:diagnosis*