ParamAP: Standardized Parameterization of Sinoatrial Node Myocyte Action Potentials  Christian Rickert, Catherine Proenza  Biophysical Journal  Volume 113, Issue 4, Pages 765-769 (August 2017) DOI: 10.1016/j.bpj.2017.07.001 Copyright © 2017 Biophysical Society Terms and Conditions

Figure 1 Schematic illustration of AP parameters reported by ParamAP. Shown here are the representative AP waveform (top) and first derivative of AP (bottom). PP (top, black dot), and MDP1 and MDP2 (top, blue dots), mark the extrema of the AP waveform. DDR (top, orange dots, and line) is determined from the best linear fit segment from a search within a predefined time interval. EDD, LDD, DD, APD, APD50, and APD90 are indicated with horizontal gray lines (top). APA is indicated by a vertical black line (top). MUV and MRR (bottom, green dots) mark the extrema of the first derivative of the AP waveform. THR (top and bottom, red dots, and dashed red line) is determined from the best linear fit (bottom, red dots, and red line) within a predefined time interval in the first derivative trace (DDD; bottom, dashed red line) plus 0.5 mV/ms. To see this figure in color, go online. Biophysical Journal 2017 113, 765-769DOI: (10.1016/j.bpj.2017.07.001) Copyright © 2017 Biophysical Society Terms and Conditions

Figure 2 Robust analysis of a wide range of AP waveforms. Given here are representative results returned by ParamAP for four distinct AP waveforms. Shown are membrane potentials (green and blue circles), rates of change of membrane potential (open circles), THR (red circle), DDR (dashed line), and APDs (horizontal lines and black circles). See User Manual in the Supporting Material for complete details of ParamAP output. To see this figure in color, go online. Biophysical Journal 2017 113, 765-769DOI: (10.1016/j.bpj.2017.07.001) Copyright © 2017 Biophysical Society Terms and Conditions