Mathematical modelling of the effects of the combination of beta-stimulation with high pacing frequency in control and hypertrophic cardiomyopathy cardiomyocytes. (A and B) Representative superimposed action potential traces (left), Ca2+-transient traces (centre), and active tension (right), elicited during stimulation at 1, at 2 Hz, or during a combination of 2 Hz pacing and β-adrenergic stimulation, in simulated CTR (A) and hypertrophic cardiomyopathy (B) myocytes. (C) Average percentage variation of physiological parameters (action potential duration at 90% repolarization, Ca-transient amplitude, Ca2+-transient time to 50% decay, active tension decay to 50% relaxation) upon combined increase of pacing rate from 1 to 2 Hz and β-adrenergic stimulation, as estimated from populations of CONTROL and hypertrophic cardiomyopathy models. (D) Average percentage variation of force amplitude upon combined 2 Hz pacing/β-stimulation. (C and D) Means ± SEM from 210 models. *P < 0.05, paired Student’s t-test.
