| 박재형¹, 박희남¹, 고경정¹, 김숙경¹, 장진근¹, 최종일¹, 임홍의¹, Chun Hwang,² 김영훈 ¹ |
Background Radiofrequency catheter ablation (RFCA) of atrial fibrillation (AF) guided by complex fractionated atrial electrogram (CFAE) has been known to be effective for eliminating AF in the selected patients, however, underlying electrophysiology of CFAE has not been clearly elucidated yet. We hypothesized the left atrial (LA) voltage and conduction pattern affects the CFAE.
Methods and Results We performed RFCA of AF in 30 patients (14 Paroxysmal AF, 22 male, 54.8±10.7 years old) guided by NavX. Color coded CFAE map, voltage maps during AF and high right atrial (HRA) pacing (500ms), and isochronal map were generated by contact bipolar electrogram (70-100 points in the LA), and analyzed by image-pro software in the anterior posterior and posterior anterior views, respectively. Each map was divided to 4 quadrants and local differences of CFAE cycle length (CL), voltage, and conduction velocities (CV) were compared. Results: 1. The areas with mean LA voltage < 2.0 mV during HRA pacing showed lower CV (0.6±0.2m/s vs. 0.9±0.4m/s, p<0.01). 2. The LA voltage during AF was correlated to that during pacing at HRA (R=0.43, p<0.001), although LA voltage during AF (2.6±2.2mV) was lower than that during pacing (5.8±2.6mV, p<0.01). 3. The quadrants with CFAE CL <120ms had higher voltage than those >120 ms (3.4±3.1mV vs. 2.1±1.3mV, p<0.01 during AF; 7.0±4.6mV vs. 4.1±2.7mV, p<0.001 during pacing). 4. Anterior right superior quadrant (septum) had shortest CFAE CL (133.3±67.7ms) and posterior right inferior quadrant had longer CFAE CL (176.5±87.2ms) than other areas (149.9±71.5ms, p=NS). In the posterior left inferior quadrant (perimitral area), CFAE CL had good correlation with CV (R=0.71, p<0.01), however, CFAE CL was not related to CV in other areas
Conclusion CFAE CL < 120ms had higher LA voltage and CFAE CL was related to the CV only at the perimitral area. However, the most areas of CFAE did not correlate with areas of slowed conduction or low voltage zone. Therefore, more detailed assessment of underlying electrophysiological substrate for CFAE is required.
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