Click on image to view larger version.

Figure 3 Interatrial conduction delay. Interatrial conduction delay was estimated by measuring the interval from S2 at high right atrial (HRA) to the first sharp deflection of A2 at the distal coronary sinus (CS), and was calculated as the time interval between atrial response at the distal CS (A1A2) and the stimulus coupling interval (S1S2), that is, A1A2 – S1S2. The maximal interatrial conduction delay was then determined. Abbreviations as in Figure 2.