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. Author manuscript; available in PMC: 2011 Nov 1.
Published in final edited form as: Heart Rhythm. 2010 Jul 3;7(11):1686–1694. doi: 10.1016/j.hrthm.2010.06.032

Figure 6.

Figure 6

EKG recordings of complex ectopy: Bigeminy and Trigeminy correspond to CaiO

A: EKG recording of paced rhythm with bigeminy. Each paced beat (green arrows) is followed by a ventricular ectopic beat (red arrow). T-waves on EKG signals are indicated by black arrows. Note that neither Vm nor Cai recover to baseline before the ectopic beat; in this sense, the paced/ectopic beat can be understood as a single complex AP.

B: An episode of trigeminy from the same experiment. Two paced beats are followed by an ectopic beat. The optical tracings indicate that alternans between a short monophasic paced AP and a “bigeminal” AP underlies the trigeminal pattern.

C: Simultaneous EKG and Cai tracing with brief runs of polymorphic VT. Pacing rate was 50 bpm with 2:1 capture. Each run of polymorphic VT corresponds to a single CaT with multiple secondary CaiO.