Despite the doubtless advances in the knowledge of cardiac electrophysiology, the mechanism of action of antiarrhythmia and the considerable clinical experience with these drugs, treatment of arrhythmia remains on a trial error basis. The authors tried to use the system serving the transmission of one lead electrocardiograms by telephone as a means of checking and correcting antiarrhythmia treatment. It is a method which despite its unpretentious character and reliability is used on a very limited scale. As compared with other contemporary means of the control of the effect of antiarrhythmia treatment, i.e. above all Holter's method or investigation of plasma levels of antiarrhythmia drugs, it is less time consuming and cheaper. The preliminary results of the authors, based on initial experience, are encouraging.