Influence of field potential duration on spontaneous beating rate of human induced pluripotent stem cell-derived cardiomyocytes: Implications for data analysis and test system selection.
INTRODUCTION
Field potential duration in human pluripotent stem cell (hiPSC)-derived cardiomyocytes is discussed as parameter for the assessment of drug-induced delayed repolarization. In spontaneously beating hiPSC-derived cardiomyocytes field potential duration varies depending on beating rate but beating rate can also be influenced by field potential duration. This interdependence is not fully understood and therefore mandates careful data analysis and cautious interpretation of the results.


METHODS
We analysed data from several types of hiPSC-derived cardiomyocytes and, for comparison, primary embryonic chick cardiomyocytes using reference compounds to study the relationship between spontaneous rate and field potential duration. Based on such data we developed a method based on a regression model of drug-induced changes in the inter-beat interval versus changes in the field potential duration to distinguish primary rate from repolarisation effects.


RESULTS
We demonstrate the application of this approach with reference and research compounds. Cells from different sources differed with regard to the direct or indirect effects of reference compounds on spontaneous beating. All cell types showed an adaptation of field potential duration upon rate changes induced by reference compounds, however, the adaptation of the spontaneous rate after compound-induced changes in field potential duration varied considerably between cell types.


DISCUSSION
As shown by comparison with data from guinea pig papillary muscle, an ex vivo model with a fixed stimulation rate, this approach is more appropriate than the application of correction algorithms routinely used for in vivo data since such algorithms do not account for a dependence of rate on field potential duration.
['Rast|Georg|G|', 'Kraushaar|Udo|U|', 'Buckenmaier|Sandra|S|', 'Ittrich|Carina|C|', 'Guth|Brian D|BD|']
D000200:Action Potentials D023401:Animal Use Alternatives D000818:Animals D018929:Cell Culture Techniques D002478:Cells, Cultured D002642:Chick Embryo D006168:Guinea Pigs D006339:Heart Rate D006801:Humans D057026:Induced Pluripotent Stem Cells D008955:Models, Cardiovascular D009200:Myocardial Contraction D032383:Myocytes, Cardiac D010210:Papillary Muscles D013997:Time Factors
Cardiomyocyte Delayed repolarization Methods Drug safety Induced pluripotent stem cell Proarrhythmic risk Rate correction algorithm