Impact of atrial functional substrate in patients with atrial fibrillation: The potential utility of decremental evoked potential mapping in the atrium

Figures

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  Figure 1. Definition of atrial decremental evoked potential (DEEP). Atrial DEEP was defined as atrial bipolar electrograms (EGMs) exhibiting a local activation delay of more than 10 ms after an extrastimulus (S2) as compared with the previous beat (S1). (Left) Several EGMs recorded during S1 of 600 ms and after S2 (10 ms above the atrial refractoriness) exhibiting a minimal change (<10 ms) in EGM duration, indicating DEEP–. (Right) In contrast, several EGMs showed a notable decrement of more than 10 ms after S2 as compared with the previous beat (S1) defined as DEEP+. These were recorded on the left atrial roof. LA = left atrial; LIPV = left inferior pulmonary vein; LSPV = left superior pulmonary vein; RIPV = right inferior pulmonary vein; RSPV = right superior pulmonary vein.

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  Figure 2. Study enrollment. During study periods, 213 patients who underwent atrial fibrillation (AF) ablation at Tottori University Hospital were reviewed. A total of 111 patients were excluded due to the exclusion criteria. As a result, 102 patients were included in this study. Fifty-four patients exhibited decremental evoked potential (DEEP) properties, while 48 patients did not exhibit DEEP properties.

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  Figure 3. Regional distribution of decremental evoked potential (DEEP) according to the 2 different pacing sites. DEEP mapping was performed at the left atrial (LA) roof and posterior wall from 2 different pacing sites (endocardially from the left atrial appendage [LAA] and epicardially from the proximal coronary sinus [CS]). DEEP was equally distributed between the LA roof and posterior wall. Per analysis according to the pacing site, there was a tendency for DEEP to be observed more frequently with CS pacing than LAA pacing; however, there was no significant difference. LIPV = left inferior pulmonary vein; LSPV = left superior pulmonary vein; RIPV = right inferior pulmonary vein; RSPV = right superior pulmonary vein.