Shorter AP duration with faster repolarization in RVCM. (A) Representative traces of AP in LVCM (black line) and RVCM (gray line). APs were evoked by 6 ms of square pulse under the current-clamp mode of nystatin-perforated whole-cell patch clamp. (B) Membrane capacitance (C_m) separately measured under the conventional whole-cell mode (n = 29 and 27, n = 6). (C–M) Summary of AP parameters measured in the nystatin-perforated recordings (n = 22 and 19, n = 5). (C) Peak amplitude; from RMP to peak depolarization. (D) Peak time; time difference between the onset of stimuli and the peak AP (the distance between the two vertical arrows in A). (E) RMP. (F) Maximal increasing speed; the maximum speed of AP depolarization. (G) Maximum increasing time; the time point showing the maximum increasing speed from the onset of stimuli. (H) Maximum decreasing speed; the maximum speed of AP repolarization after the peak. (I) Maximum decreasing time (MdT); the time of MdT from the onset of stimuli. (J) Peak to MdT; the time duration from AP peak to MdT. (K–M) APD₁₀, APD₅₀, and APD₉₀, representing the time to repolarize 10, 50, and 90% from the peak, respectively. All statistical tests performed using nested t test. **, P < 0.01; ***, P < 0.001; ****, P < 0.0001. The gray dot means the measured value of individual cells, and the block dot represents the average of the measured value for each animal. The black line in the column means average of measured value. Repol, repolarization.