PubMed1992
The therapeutic approach to cardiac arrhythmias is constantly evolving due to our improved understanding of their mechanisms and clinico-prognostic implications, even if uncertainties and controversies continue to be a marked feature of this sector, perhaps more than in any other field of medicine. The frequent finding of cardiac arrhythmias in the healthy and cardiopathic population justifies the importance which the question of the diagnosis and treatment of cardiac rhythm disorders has now assumed, even if, as far as the latter is concerned, the aggressive approach has been considerably modified over the past years. This has occurred in view of the still unproven value of indiscriminate anti-arrhythmic treatment for the purposes of prolonging life. This treatment has only been demonstrated to be of value in a few studies in selected subgroups of high-risk patients. In addition, it should be underlined that it has been reported that anti-arrhythmic drugs may possible aggravate or induce new arrhythmia. This potential pro-arrhythmic effect has become increasingly recurrent due to the widespread use and diffusion of this category of drugs. Such considerations should therefore encourage greater caution in the use of these drugs. Cardiac arrhythmias may be benign or life-threatening, symptomatic or asymptomatic; they may be a warning sign of sudden death, or be the cause or effect of heart failure, be the expression of an acute or chronic heart disease, or the clinical manifestation, at a cardiac level, of an extracardiac pathology. Within this broad-ranging clinical context, arrhythmia often gives rise to therapeutic dilemmas which must be resolved with extreme rationality, taking into account the results of all available clinical trials. The results of the Cardiac Arrhythmias Suppression Trial (CAST) showed that clinical judgements of therapeutic efficacy, made in the absence of carefully controlled studies, are often incorrect. On the basis of these findings beta-blocking drugs may find increasing use, since while they are not anti-arrhythmic drugs in the strict sense of the term, they are safer due to their negligible pro-arrhythmic effect, the lower incidence of collateral effects and their proven efficacy in post-infarction. The role of beta-blockers in the treatment of manifest heart failure should not be over-looked, since by countering the deleterious effect of increased catecholamines they may improve the prognosis, thus reducing the incidence of sudden death.
Adrenergic beta-Antagonists↗