Skip to main content
. Author manuscript; available in PMC: 2013 Apr 1.
Published in final edited form as: Circ Arrhythm Electrophysiol. 2012 Mar 9;5(2):371–379. doi: 10.1161/CIRCEP.111.969493

Figure 6.

Figure 6

Effect of atropine (10 μM) and subthresold pulses on phase 4 depolarization in superior vena cava sleeve preparations. A: Control action potentials (APs) recorded at basic cycle length (BCL) of 2000 to 50 ms displaying phase 4 depolarization and marked hyperpolarization following fast pacing. B: Atropine eliminates phase 4 depolarization as well as fast pacing-induced hyperpolarization. C. Following pacing at BCL of 500 ms, subthresold pulses introduced at a frequency of 50 Hz induce marked hyperpolarization.