Future trends in antiarrhythmic therapy

It is difficult to define what the trends will be in antiarrhythmic therapy in the coming years, particularly at a time when rhythmology has been somewhat destabilized by the unexpected results of large therapeutic trials on sudden death prevention. Schematically, drugs that do have established antiarrhythmic properties do not provide any benefit, and they can even make the patients' situation worse. On the other hand, beta-blockers, which do not satisfy the admitted rules of antiarrhythmic efficacy, are indeed capable of preventing death, and they are so doing in subgroups with heart failure, a classic contraindication. Finally, drugs such as calcium antagonists, which supposedly address the ischemic mechanism of death, do not seem to provide any benefit in this kind of trial, whereas drugs such as amiodarone have such a complex action that their probably favorable effect is not easy to explain. This uncomfortable situation probably relates to the fact that the various modes of reasoning concerning the mechanisms of arrhythmias and the effects of drugs have been too straightforward, not to say simplistic. Routinely observed arrhythmias may not have the same determinants as the arrhythmias finally responsible for death, particularly if the role of adrenergic stimulation is taken into account to explain the difference in severity. Routinely used antiarrhythmic drugs may well be effective on the former and innocuous for the patients, and at the same time ineffective on the latter and detrimental to the more severely diseased patients. Our modes of evaluation of the real effects of the drugs certainly have to be revisited, as well as the important parameters to be taken into account in the evaluation of arrhythmias.(ABSTRACT TRUNCATED AT 250 WORDS)