Electroanatomic mapping during atrial fibrillation revealed lower global mean voltage compared to paced rhythm (0.7 vs. 2.1 mV, P<0.001), showing CFE sites do not necessarily mark abnormal substrate.
Observational (n=12)
Does the presence of complex fractionated electrograms (CFE) and low voltage during AF correlate with abnormal atrial substrate during paced rhythm in patients with persistent AF?
Areas of complex fractionated electrograms and low voltage during AF frequently demonstrate normal atrial myocardial characteristics during sinus rhythm, indicating they do not necessarily identify abnormal atrial substrate.
Absolute Event Rate: 0.7% vs 2.1%
p-value: p=<0.001
AIMS: Mapping of atrial fibrillation (AF) involves identification of low-voltage regions associated with complex fractionated electrograms (CFE) which theoretically represent abnormal substrate and targets for ablation. Whether low-voltage CFE areas also identify abnormal substrate during paced rhythm is unknown. METHODS AND RESULTS: Twelve patients with persistent AF undergoing ablation of AF had high-density three-dimensional electroanatomic maps created during AF and paced rhythm (24 maps) and the mean voltage during AF and paced rhythm was compared for eight segments of the left atrium (LA). The following were correlated during AF and paced rhythm: regional mean voltage; %low voltage (defined as <0.5 mV); and extent of CFE. In addition, the relationship between the extent of CFE in AF: (i) %low voltage and (ii) conduction during paced rhythm were determined. Mean voltage was lower during AF than paced rhythm for all regions and globally (0.7 ± 0.2 mV vs. 2.1 ± 0.6 mV, P < 0.001). The regional and overall %low voltage of the LA was greater during AF than paced rhythm (53 ± 19% vs. 9 ± 2%, P < 0.001). There was no correlation between mean voltage or %low voltage during AF and paced rhythm. Complex fractionated electrograms were prevalent throughout all regions during AF, but did not correlate with %low voltage, fractionation, or slowed conduction during paced rhythm. CONCLUSION: Areas of CFE and low voltage recorded during AF frequently demonstrate normal atrial myocardial characteristics (normal conduction, electrograms, and voltage) during sinus rhythm. Therefore, AF CFE sites do not necessarily identify regions of an abnormal atrial substrate. However, this does not exclude the possibility that CFE might identify a focal driver or source occurring in a region of normal atrial myocardium.
Teh et al. (Tue,) conducted a observational in persistent atrial fibrillation (n=12). Electroanatomic mapping during atrial fibrillation vs. Electroanatomic mapping during paced rhythm was evaluated on Global mean voltage (p=<0.001). Electroanatomic mapping during atrial fibrillation revealed lower global mean voltage compared to paced rhythm (0.7 vs. 2.1 mV, P<0.001), showing CFE sites do not necessarily mark abnormal substrate.