We use whole cell patch clamp technique to investigate electrophysiological properties of myocytes isolated by means of enzyme dissociation from the different regions of small mammalian hearts. We determine the restitution properties of action potentials of isolated myocytes at different pacing rates during normal and abnormal responses (alternans). We aim to understand the transition from the normal responses to alternans at the cellular level.
We use high resolution optical mapping technique to records electrical activity (action potentials) from the epicardial surface of the small mammalian hearts with the help of voltage-sensitive dyes. Our dual-cameras set up allows recording from >80% of the heart surface.
We perform numerical simulations of the physiological ionic models of cardiac action potentials in different species aiming to compliment and to further drive our previously described experiments. We use a novel approach reflecting the influence of ionic currents kinetics on the dynamic characteristics of periodically paced cardiac myocytes to achieve a good qualitative and quantitative agreement with experimental data.