A, Voltage-clamp protocol (top) and representative recordings of SCaEs (Fluo-3, middle) and corresponding INCX (bottom) from a Ctl (left) and cAF (right) myocyte, respectively following steady-state stimulation for 1-minute at 0.5 Hz. B, Susceptibility to SCaEs in Ctl and cAF. *P<0.05 vs. Ctl (Fisher’s exact test). C, Mean±SEM frequency (left), latency (middle), and amplitude (right) of SCaEs in Ctl and cAF. D, Mean±SEM amplitude of SCaE-generated INCX. C,D, *P<0.05 and **P<0.01 vs. corresponding means in Ctl. Numbers indicate myocytes/patients.