Left atrial very low-voltage regions strongly associated with anatomical contact areas, and high dominant frequency sites exhibited significantly lower mean voltage than complex fractionated sites (0.62 vs. 1.54 mV).
Cross-Sectional (n=22)
No
Left atrial anatomical contact areas are strongly associated with very low-voltage regions and fractionated electrograms, suggesting a structural basis for atrial fibrillation maintenance.
Absolute Event Rate: 0.62% vs 1.54%
p-value: p=<0.0001
BACKGROUND: Atrial low-voltage areas are suggested to be related to maintenance of atrial fibrillation (AF). The influence of the left atrium (LA) contact area (CoA) has not been investigated. METHODS AND RESULTS: Twenty-two persistent AF patients underwent high-density mapping during AF and sinus rhythm (SR). Three representative CoA regions in the LA (ascending aorta: anterior wall; descending aorta: left inferior pulmonary vein LIPV; and vertebrae: posterior wall) were identified. Electrogram analysis of both high dominant frequency (high-DF; >8 Hz) and complex fractionated atrial electrogram (con-CFAE; <50 ms) regions during SR was done. The anatomical relationship between CoA and both the very low-voltage areas (vLVA; <0.2 mV) and high-frequency sources was determined. Forty-seven vLVA (194.4 cm(2)) and 60 CoA (337.0 cm(2)) were documented, and 32 vLVA directly overlapped CoA. The vLVA were preferentially found in the anterior (45%) and posterior (13%) walls of the LA, and in the LIPV (13%), and corresponded to CoA sites. The mean voltage during SR at high-DF sites was significantly lower than that at con-CFAE sites (0.62 vs.1.54 mV; P<0.0001). Seventy-two percent of high-DF sites overlapped CoA, while 54% of con-CFAE did. Furthermore, 44% of high-DF surface area directly overlapped CoA, while only 19% of con-CFAE did. CONCLUSIONS: Very low-voltage regions had a strong association with CoA. Sites with CoA had a higher incidence of fractionated electrograms both during SR and AF.
Hori et al. (2014) conducted a cross-sectional in Persistent Atrial Fibrillation (n=22). Left atrium anatomical contact area (CoA) vs. Non-contact areas was evaluated on Mean bipolar voltage during sinus rhythm at high dominant frequency (high-DF) sites vs continuous complex fractionated atrial electrogram (con-CFAE) sites (p=<0.0001). Left atrial very low-voltage regions strongly associated with anatomical contact areas, and high dominant frequency sites exhibited significantly lower mean voltage than complex fractionated sites (0.62 vs. 1.54 mV).