The Human Cardiac Electrophysiology Group is investigating the excitability of cardiomyocytes mainly isolated from the human heart. Myocyte isolation is carried out by using Langendorff preparation (guinea pig) and the chunk method (atrial appendage, ventricular tissue). Using the patch-clamp technique in the whole cell mode we are characterizing the electrical behaviour (action potentials, ionic currents) of cardiomyocytes under physiological as well as pathophysiological conditions. Furthermore (side-) effects of clinically interesting drugs on electrophysiological parameters are investigated by our group. Experimental studies are completed by mathematical modelling of single cell excitability.