Preface [Hot topic: Antiarrhythmics (Guest Editor: P. Matyus)]

Cardiac arrhythmias represent a major area of cardivascular disease research. Of the possible medical treatments of arrhythmias, drug therapy has gained great importance. In spite of the significant progress achieved in the basic understanding of the electrophysiology and molecular biology of transmembrane ion channels and transporters underlying the mechanism of cardiac arrhythmias and possible drug actions, during the last decade no breakthrough has occurred in the therapy. On the contrary, based on multicentric clinical trials, it is now evident that serious side effects may considerably limit the use of currently available antiarrhythmic agents to abolish or prevent atrial fibrillation and life threatening ventricular tachycardias. Therefore, it seems worthwhile to review some of the possible mechanisms which could taken into account in future drug development strategies. In this ‘Hot topic’ issue, there are included five papers by experts of the field, in which some new aspects, and opinions regarding the possible mechanisms of new drugs under and future developments are described. The first article by Andras Varro et al. summarizes in general the basic electrophysiology of the transmembrane ion channels and possible consequences of their modulation. The paper of Juan Tamargo et al. focuses on various aspects of current and future drug therapy of atrial fibrillation. Joseph Salata et al. and Péter Nánási et al. in their overviews express partly different opinions regarding the future perspectives of the inhibition of the slow delayed rectifier outward potassium current (IKs) as a possible antiarrhythmic strategy. In the last paper, Peter Mátyus et al. present the medicinal chemistry of a new series of compounds with a dual mode of action designed and developed at their own labs. supporting the concept that a finely tuned blockade of carefully selected ion channels may result in a therapeutically particularly valuable profile. We do hope that all papers per se, and the issue in its entirety, will give the reader some hints to understand the complexity of antiarrhythmic drug therapy, and will initiate further research in this area.