October 1, 2000Open Access
Endocardial activation during ventricular fibrillation in normal and failing canine hearts
Structured PICO
Does congestive heart failure alter the endocardial activation characteristics during ventricular fibrillation in a canine model?
P
Population
13 dogs (7 with congestive heart failure induced by combined myocardial infarction and rapid ventricular pacing, and 6 normal dogs)
I
Intervention
Endocardial activation mapping during ventricular fibrillation using a noncontact, multielectrode array balloon catheter
C
Comparator
Normal dogs (n=6)
O
Outcome
Endocardial activation characteristics during ventricular fibrillation (peak/centroid frequency, number of simultaneous noncontiguous wavefronts, wavefront turnover rate)surrogate
Dilated abnormal ventricles in a canine CHF model sustain fewer active wavefronts during ventricular fibrillation compared to normal ventricles, despite similar fundamental frequency characteristics.
Abstract
Because congestive heart failure (CHF) promotes ventricular fibrillation (VF), we compared VF in seven dogs with CHF induced by combined myocardial infarction and rapid ventricular pacing to VF in six normal dogs. A noncontact, multielectrode array balloon catheter provided full-surface real-time left ventricular (LV) endocardial electrograms and a dynamic color-coded display of endocardial activation projected onto a three-dimensional model of the LV. Fast Fourier transform (FFT) analysis of virtual electrograms showed no difference in peak or centroid frequency in CHF dogs compared with normals. The average number of simultaneous noncontiguous wavefronts present during VF was higher in normals (2.4 +/- 1.0 at 10 s of VF) than in CHF dogs (1.3 +/- 1.0, P < 0.005) and decreased in both over time. The wavefront "turnover" rate, estimated using FFT of the noncontiguous wavefront data, did not differ between normals and CHF and did not change over 5 min of VF. Thus the fundamental frequency characteristics of VF are unaltered by CHF, but dilated abnormal ventricles sustain fewer active wavefronts than do normal ventricles.