Experimental analysis of the fundamental proarrhythmic and antiarrhythmic mechanisms will be performed in the heart and cardiac preparations in the following four areas:

1)Elucidation of the relationship between the proarrhythmic decrease of the repolarization reserve and altered transmembrane potassium currents (I_Kr, I_Ks, I_k1) as well as potassium channel expression, with particular regard to heart failure and diabetes.

2)Clarification of the anti- and/or proarrhythmic nature of the cardiac electrophysiological changes due to selective inhibition of potassium currents (I_to and I_k1).

3)Discovery of the correlation between the damage of the function of 'gap-junction' channels and conduction disturbances; the possibilities of stimulation of these channels by pharmacological means.

4)Establishment of the cardiac electrophysiological mechanisms underlying the antiarrhythmic action of ischaemic preconditioning.

From the completion of the research tasks outlined in the summary of content of the investigation (item "g") a better understanding of the cellular pathophysiological background of cardiac arrhythmias, of the fundamental mechanisms of the proarrhythmic action of heart failure and diabetic cardio-myopathy and of the favourable cardiac electrophysiological changes resulting in the antiarrhythmic activity of ischaemic preconditioning, can be expected.

All this may constitute a starting point for the development of entirely new-type (among others selective potassium channel blocking, 'gap-junction' stimulating) antiarrhythmic drugs.