ActionPytential: An open source tool for analyzing and visualizing cardiac action potential data

Figures

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  Fig. 1. Representative ventricular action potentials from various species (Ai – human, Aii – rabbit, Aii – guinea pig, Aiv – rat, Bi – dog) and from other cardiac tissue types (Bii – dog Purkinje fiber, Bii – dog sinoatrial node, Biv – dog atrium). The phases of the cardiac ventricular action potential are denoted as red numbers in Ai: phase 0, rapid depolarization; phase 1, early rapid repolarization; phase 2, plateau; phase 3, late repolarization; phase 4, resting membrane potential. The phases of the sinoatrial node action potential are denoted as blue numbers in Bii: 4, early diastolic depolarization; 0, rapid depolarization; 1–3, repolarization.

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  Fig. 2. The ActionPytential user interface.

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  Fig. 3. – A flowchart presenting an overview of the data flow in ActionPytential.

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  Fig. 4. Separated sinoatrial action potentials from a gap-free recording shown in continuous (A) and in stacked (B) views.

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  Fig. 5. Definitions of the resting membrane potential, the action potential amplitude and the conduction time on a rat ventricular muscle action potential. The box on the left shows the first 8 ms of the same recording; SA – stimulation artifact.

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  Fig. 6. Definitions of the action potential duration at a given percent of repolarization on an action potential from dog ventricular muscle.

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  Fig. 7. Definitions of the notch-related parameters on a dog Purkinje fiber action potential.

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  Fig. 8. The timepoint where the notch occurs (NT) was not detected correctly in unfiltered cardiac action potential data with additional noise (A). After applying Butterworth filtering (120 Hz), the notch was correctly detected at up to 2 SD additional noise (B). Tickmarks in the legend represent correct detection. Colored arrowheads on the time axis represent the NT detected for the corresponding sweep. On the right, the arrowheads for No noise, 1 SD and 2 SD overlap.

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  Fig. 9. Definitions of the plateau-related parameters on a human ventricular muscle action potential. PV50: plateau voltage at the midpoint of the action potential duration, where the midpoint is calculated by halving the APD90 value.

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  Fig. 10. The manual analysis window.