Individual ( A ) and summarized ( B ) values for mean electromechanical activation time (EMAT) during diaphragmatic stimulation for time-synchronous DDD (right atrium-left ventricle)-diaphragmatic pacing with different coupling intervals ( n = 11). The boundaries of the boxes indicate the 25th and 75th percentiles, the whiskers indicate minimum and maximum values, and the horizontal line marks the median value. DDD (no PIDS), DDD mode without diaphragm stimulation; EMAT, electromechanical activation time; PIDS-Vp 10 ms (or 20 or 30 ms), ventricle stimulation 10 ms (or 20 or 30 ms) after diaphragmatic stimulation; Vp-PIDS 10 ms (or 20 or 30 ms), diaphragmatic stimulation 10 ms (or 20 or 30 ms) after ventricle stimulation.