1. Cardiac Purkinje cells
Penelope A. Boyden, PhD, Masanori Hirose, MD, PhD, Wen Dun, MD, PhD 
Heart Rhythm 
Volume 7, Issue 1, Pages (January 2010)
DOI: /j.hrthm
Copyright © 2010 Heart Rhythm Society Terms and Conditions

2. Figure 1
A: Bipolar recordings from a specialized conducting system at various locations (1–6) in the in situ canine heart. Upper electrode is fixed on the His-Purkinje bundle. Note H deflection is His activation. Lower electrode records at sites from right bundle branch (1) to left anterior false tendon (6). P indicates activation of Purkinje fibers. Time lines = 40 ms.3B: Transmembrane action potential of kid Purkinje fiber during spontaneous activity. Numbers indicate value of membrane resistance during electrical activity.73
Heart Rhythm 2010 7, DOI: ( /j.hrthm )
Copyright © 2010 Heart Rhythm Society Terms and Conditions

3. Figure 2
Recordings from distal poles of a mapping catheter in a patient with ventricular tachycardia. Evidence for participation of Purkinje fibers in the ventricular tachycardia circuit is shown by the presence of the Purkinje potential during ventricular tachycardia (Map) as well as during sinus rhythm at the same site (A, B). Pace mapping at the Purkinje site matched ventricular tachycardia morphology (C, D).7
Heart Rhythm 2010 7, DOI: ( /j.hrthm )
Copyright © 2010 Heart Rhythm Society Terms and Conditions

4. Figure 3
Lack of spontaneous impulse generation in single canine Purkinje cells. A: Fine-tip microelectrode recordings of a single Purkinje cell show small depolarizations during diastole in a well-polarized cell (–90 mV). B: Paced Purkinje cell with a normal diastolic potential but no spontaneous activity. C: Absence of pacemaker activity in canine Purkinje cell in the presence of 2.7 mM Ko (–90 mV).36
Heart Rhythm 2010 7, DOI: ( /j.hrthm )
Copyright © 2010 Heart Rhythm Society Terms and Conditions

5. Figure 4
Action potential–evoked Ca2+ transients (A) and spontaneous Ca2+ wave (B) in normal Purkinje cell aggregates. Top panels show fluorescence intensity of Ca2+ in two Purkinje cells during depolarization (A) and spontaneous Ca2+ wave (B). a–c correspond to three-dimensional surface plots of ratio images of a section of these aggregates. Ca2+ concentration is reflected by both the color and the height of the surface. The first response to a stimulus is an increase in Ca2+ (A, a), which is present mostly at the aggregate's periphery (A, b). Peak Ca2+ change occurs later in the core of the aggregate (A, c). White line on surface plot (A, c) corresponds to 10 μm. B: Spontaneous cell-wide Ca2+ wave moving along four regions of a normal Purkinje cell. A small Ca2+ transient appears at the edge of the aggregate (B, a) and induces the Ca2+ wave. Thick white line on surface plot (B, c) corresponds to 26 μm for all surface plots.44
Heart Rhythm 2010 7, DOI: ( /j.hrthm )
Copyright © 2010 Heart Rhythm Society Terms and Conditions

6. Figure 5
Large extensive Ca2+ waves in a Purkinje cell aggregate lead to sufficient depolarization to elicit an action potential. A: Selected F/Fo images from a Purkinje cell aggregate during Ca2+ wave-induced electrical activity. Time relative to t = 0 of first frame is depicted by white numbers.Lower right image is bright-field image of this aggregate. Arrow indicates a cell border. B: Transmembrane action potential changes (black line) and changes in F/Fo in several regions of interest in spontaneously active Purkinje cell shown in A (maximum diastolic potential [MDP] = –84.5 mV). Nondriven action potentials are triggered by large cell-wide Ca2+ waves (CWW). Inset shows enlargement of Ca2+ wave preceding synchronized Ca2+ release induced by the second action potential (arrow). Images in A occurred during time of the dotted line. Note a Ca2+ wavelet (μCaiT) occurs between the nondriven beats. Thick vertical and horizontal lines correspond to 1 F/Fo unit and 3 seconds (1 F/Fo, 417 ms for inset), respectively. Thin vertical black line corresponds to 12 mV.44
Heart Rhythm 2010 7, DOI: ( /j.hrthm )
Copyright © 2010 Heart Rhythm Society Terms and Conditions

7. Figure 6
Line scans of subsarcolemmal (SSL) and core regions from one Purkinje cell from normal heart (NZPC) and one Purkinje cell from 48-hour infarcted heart (IZPC). Line scan images (bottom panels) and their three-dimensional plots (top panels) are shown for each cell. Note that Ca2+ spark rate and amplitudes were higher in the SSL region in IZPC than in NZPC (Stuyvers et al, unpublished data).
Heart Rhythm 2010 7, DOI: ( /j.hrthm )
Copyright © 2010 Heart Rhythm Society Terms and Conditions