Epicardial-to-Endocardial Activation Gradients and Conduction Block During Atrial Fibrillation in the Human Left Atrial Posterior Wall

Figures

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  Figure 1.. Three-dimensional maps demonstrating standardized positions for simultaneous endocardial and epicardial mapping. Representative 3-dimensional maps demonstrating standardized positions for simultaneous endocardial and epicardial mapping: mid-posterior wall (A and B), mid-inferior left atrium (C), inferolateral left atrium (D). Overlapping multipolar catheters (Advisor HD Grid, Abbott) are shown on the endocardial (purple) and epicardial (green) left atrial surfaces.

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  Figure 2.. Catheter proximity for simultaneous endocardial and epicardial mapping. Representative 3-dimensional maps demonstrating the proximity of multipolar catheters (Advisor HD Grid, Abbott) during simultaneous endocardial and epicardial mapping. Distances between catheters are measured and vary between 4 and 5 mm.

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  Figure 3.. Representative examples of epicardial-endocardial bipolar voltage discrepancy during atrial fibrillation from 2 de novo patients with simultaneous epicardial and endocardial mapping, and an example of epicardial ablation. A and C, Endocardial bipolar voltage maps, and B and D demonstrate epicardial bipolar voltage maps. E, Typical lesion set for epicardial ablation. F, Postepicardial ablation map. Voltage scale from 0.05 mV (red) to 0.5 mV (purple).

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  Figure 4.. Simultaneous bipolar epicardial and endocardial voltage mapping. A, Sinus rhythm (SR) endocardial (Endo) bipolar voltage. B, SR epicardial (Epi) bipolar voltage. C, Atrial fibrillation (AF) Endo bipolar voltage. D, AF Epi bipolar voltage. Bipolar voltage maps during SR and AF from a patient with simultaneous Epi and Endo mapping. A and B demonstrate Endo and Epi bipolar voltage maps, respectively, during SR, which show relatively healthy and comparable bipolar voltage. C and D demonstrate Endo and Epi bipolar voltage maps, respectively, during AF, which show lower voltage compared with sinus rhythm and slightly greater regions of preserved Epi bipolar voltage compared with the endocardium.

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  Figure 5.. Simultaneous epicardial and endocardial bipolar and unipolar voltage mapping. A. Atrial fibrillation (AF) endocardial (Endo) bipolar voltage. B, AF Endo unipolar voltage. C, AF epicardial (Epi) bipolar voltage. D, AF Epi unipolar voltage. Representative example of bipolar and unipolar Endo and Epi maps derived during simultaneous Epi-Endo mapping. Endo and Epi bipolar voltage maps (A and C), as well as Endo and Epi unipolar voltage maps (B and D), are shown. The unipolar Endo map (B) shows some areas where there is low Endo bipolar voltage (A) but greater Endo unipolar voltage that corresponds to greater Epi bipolar and unipolar voltage (C and D). The Endo and Epi HD grid catheter positioning corresponds to simultaneous Endo and Epi recordings. Simultaneous Endo recordings (green electrograms) demonstrate areas of low to no electrograms as compared with the Epi electrograms (orange recordings). Bipolar voltage scale from 0.05 mV (red) to 0.5 mV (purple). Unipolar voltage scale from 0.15 mV (red) to 1.0 V (purple).

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  Figure 6.. Asynchronous epicardial and endocardial conduction. A, Epicardial (Epi) leading endocardial (Endo) conduction. B, Endo leading Epi conduction. C, Greater Epi than Endo activation. D, Greater Epi>Endo activation. Representative episodes of Endo-Epi conduction during simultaneous Epi and Endo mapping. The figure shows 3-dimensional geometries, multipolar catheter (Advisor HD Grid, Abbott) positions on the Endo and Epi left atrial surfaces, and electrograms from these catheters and the decapolar catheter in the coronary sinus. A, Epi activity leading Endo activity. B, Endo activity leading Epi activity. C and D, Greater activation frequency on the Epi compared with the Endo surface.

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  Figure 7.. Variable conduction block between endocardium and epicardium. A, Endocardial (Endo) to epicardial (Epi) Wenckebach block during atrial fibrillation (AF). B, Epi to Endo Block during sinus rhythm (SR). C, Epi to Endo Block and Delay during AF. D, Epi to Endo Block During AF. For example, episodes of conduction block between the Endo and Epi left atrial posterior wall (LAPW) surfaces during simultaneous Epi and Endo mapping (SEEM). A, Single nonconducted beat due to Wenckebach conduction from the Endo to Epi surface during AF. B, Nonconducted beats from the Epi to Endo surface during sinus rhythm. C, Intermittent Epi to Endo block, and Epi to Endo delay, during AF. D, Regionally variable Epi to Endo block during AF.

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  Figure 8.. Sustained epicardial-to-endocardial conduction block. Representative episodes of sustained epicardial-to-endocardial conduction block during simultaneous epicardial and endocardial mapping (SEEM). The bottom left shows not only sustained epicardial-to-endocardial block but also transient 2:1 block on the epicardial surface. The figure shows 3-dimensional geometries, multipolar catheter (Advisor HD Grid, Abbott) positions on the endocardial and epicardial left atrial surfaces, and electrograms from these catheters and the decapolar catheter in the coronary sinus.