  Contemporary realistic mathematical models of single-cell cardiac electrical
excitation are immensely detailed. Model complexity leads to parameter
uncertainty, high computational cost and barriers to mechanistic understanding.
There is a need for reduced models that are conceptually and mathematically
simple but physiologically accurate. To this end, we consider an archetypal
model of single-cell cardiac excitation that replicates the phase-space
geometry of detailed cardiac models, but at the same time has a simple
piecewise-linear form and a relatively low-dimensional configuration space. In
order to make this archetypal model practically applicable, we develop and
report a robust method for estimation of its parameter values from the
morphology of single-stimulus action potentials derived from detailed ionic
current models and from experimental myocyte measurements. The procedure is
applied to five significant test cases and an excellent agreement with target
biomarkers is achieved. Action potential duration restitution curves are also
computed and compared to those of the target test models and data,
demonstrating conservation of dynamical pacing behaviour by the fine-tuned
archetypal model. An archetypal model that accurately reproduces a variety of
wet-lab and synthetic electrophysiology data offers a number of specific
advantages such as computational efficiency, as also demonstrated in the study.
Open-source numerical code of the models and methods used is provided.
