Spectral profiles of complex fractionated atrial electrograms are different in longstanding and acute onset atrial fibrillation atrial electrogram spectra

Abstract

Spectral Profiles of CFAE.

Background: Spectral analysis of complex fractionated atrial electrograms (CFAE) may be useful for gaining insight into mechanisms underlying paroxysmal and longstanding atrial fibrillation (AF). The commonly used dominant frequency (DF) measurement has limitations.

Method: CFAE recordings were acquired from outside the 4 pulmonary vein ostia and at 2 left atrial free wall sites in 10 paroxysmal and 10 persistent AF patients. Two consecutive 8s-series were analyzed from recordings >16s in duration. Power spectra were computed for each 8s-series in the range 3-12 Hz and normalized. The mean and standard deviation of normalized power spectra (MPS and SPS, respectively) were compared for paroxysmal versus persistent CFAE. Also, the DF and its peak amplitude (ADF) were compared for pulmonary vein sites only. Power spectra were computed using ensemble average and Fourier methods.

Results: No significant changes occurred in any parameter from the first to second recording sequence. For both sequences, MPS and SPS were significantly greater, and DF and ADF were significantly less, in paroxysmals versus persistents. The MPS and ADF measurements from ensemble spectra produced the most significant differences in paroxysmals versus persistents (P < 0.0001). DF differences were less significant, which can be attributed to the relatively high variability of DF in paroxysmals. The MPS was correlated to the duration of uninterrupted persistent AF prior to electrophysiologic study (P = 0.01), and to left atrial volume for all AF (P < 0.05).

Conclusions: The MPS and ADF measurements introduced in this study are probably superior to DF for discerning power spectral differences in paroxysmal versus longstanding CFAE. (J Cardiovasc Electrophysiol, Vol. 23, pp. 971-979, September 2012).

Figure 1

An example of complex fractionated atrial electrogram spectrum and harmonic relationships in a recording from the right inferior pulmonary vein ostium in a longstanding, persistent atrial fibrillation patient. Panel A, no harmonic removal. Panel B, removal of harmonic 2. Panel C, the Fourier power spectrum for the same recording. The mean and standard deviation in the spectral profile is given at upper right in each panel. See text for further details.

Figure 2

An example of the complex fractionated atrial electrogram spectrum and harmonic relationships in a recording from the left superior pulmonary vein ostium obtained during acutely induced atrial fibrillation in a patient with paroxysmal atrial fibrillation is shown in panel A. The mean and standard deviation in the spectral profile is given at upper right. To show how these spectral profile parameters change, values are also shown when peaks away from the dominant frequency are masked (B), when the dominant frequency peak is masked (C), and when the remaining peaks are scaled to a range of 0–1 after masking the dominant frequency (D).

Figure 3

An example of a complex fractionated atrial electrogram recording outside the right superior pulmonary vein in a patient with paroxysmal atrial fibrillation is shown in panel A. The ensemble average frequency spectrum for the recording in Panel A, in the range 3–12 Hz, is shown in Panel B (no harmonic interactions removed). An example of a complex fractionated atrial electrogram recording from the left superior pulmonary vein in persistent atrial fibrillation is shown in panel C. The ensemble average frequency spectrum for this complex fractionated atrial electrogram (no harmonic interactions removed) is shown in panel D. So that detail can be observed, only 2 seconds of recording time is shown in panels A and C. However, the spectra in panels B and D were generated from the entire 8.4 second sequence length.

Figure 4

Scatterplots of ADF versus MPS for each patient are graphed in panel A. Each solid black circle represents a persistent atrial fibrillation patient and each × represents a paroxysmal atrial fibrillation patient. Scatterplots of DF versus SPS for each patient are graphed in panel B. In panels C and D, the results are shown obtained using Fourier power spectral analysis. In each panel the best discriminating line is also shown for separating the 2 types of atrial fibrillation.

Figure 5

In the top panel, a plot is shown of persistent atrial fibrillation patient data from Figure 4A, with the duration of uninterrupted atrial fibrillation prior to electrophysiologic study noted in number of months for longstanding patients. In the lower panel, all atrial fibrillation patient data from Figure 4A are plotted, with left atrial volume noted in milliliters in all 10 longstanding atrial fibrillation and 7 paroxysmal atrial fibrillation patients. Volumetric data were not obtained for 2 paroxysmal patients (noted by −).