Does which pad delivers the first shock in DSED matter?

When performing DSED, should the first shock be delivered using the anterior-lateral or anterior-posterior pad placement? Or does the placement not significantly impact effectiveness? In the 2025 Double Sequential Review: Advanced Emergency Defibrillation Techniques (self-study 2025 package) at 16:34, the first shock is shown using the anterior-posterior placement. However, I recall you mentioning in an earlier video that the anterior-lateral placement is the recommended approach for the first shock. Could you please clarify which placement is most appropriate? Thank you.

In Double Sequential External Defibrillation which pad delivers the first shock does not appear to change outcomes. So no - which monitor is delivering the first shock is not relevant. 

What does appear to make to make a difference is minimizing the time betwen shocks as much as possible. <7 ms is the ideal timeframe betwen the two shocks. As a result, ensuring that we are preapred to push each button in rapid sequence would be the prioirty. 

References: 

Cheskes, S., Verbeek, P. R., Drennan, I. R., McLeod, S. L., Turner, L., Pinto, R., Feldman, M., Davis, M., Vaillancourt, C., Morrison, L. J., Dorian, P., & Scales, D. C. (2022). Defibrillation strategies for refractory ventricular fibrillation. The New England Journal of Medicine, 387(21), 1947–1956. https://doi.org/10.1056/NEJMoa2207304