A, conduction velocity along a line from SAN centre, through SAN periphery to atrial muscle. Top, data from rabbit heart [3]. Bottom, data from Kurata-Lindblad 1D model (x
1 = 1.2 mm, x
2 = 1.24 mm) and Zhang-Oxsoft 1D model (x
1 = 1.0 mm, x
2 = 1.32 mm) shown in Fig. 4 (physiological behaviour). B and C, maximum upstroke velocity (dV
m/dt
max, B) and overshoot and maximum diastolic potential (C) of action potentials. Top, data from intact rabbit SAN preparations (Bleeker et al. [22]; Kodama et al. [23]) and small ball-like rabbit SAN preparations (Kodama and Boyett [24]). Bottom, data from Kurata-Lindblad 1D model (x
1 = 1.2 mm, x
2 = 1.24 mm) and Zhang-Oxsoft 1D model (x
1 = 1.0 mm, x
2 = 1.32 mm) shown in Fig. 4 (physiological behaviour). RSARB is a marker for SAN-atrial muscle junction.