[Spectrum of effects of beta receptor blockade in cardiac arrhythmias].

The efficacy of beta adrenergic blocking agents has been observed in the treatment of a variety of cardiac arrhythmias. Electrophysiological experiments demonstrated that beta receptor blocking drugs prevent catecholamine-induced alterations of the transmembrane action potential. Clinically used beta blocking agents are effective in preventing arrhythmias provoked by sympathetic stimulation such as sinus tachycardia, paroxysmal junctional tachycardia, atrial, nodal, and ventricular premature contractions. Beta receptor blocking drugs are especially useful in tachycardias based on hyperkinetic heart syndrome and in exercise-induced premature beats in patients suffering from coronary heart disease. Beta blocking agents are--at least in our hands--most useful in combination with class I antiarrhythmic drugs with the intention to reduce the dosage--i.e. the side effects--of various antiarrhythmic drugs. In hyperthyroidism beta adrenergic blocking agents are effective complementary to the specific treatment. In cases of intoxication with beta blocking drugs complicated by myocardial depression and severe bradycardia glucagon must be regarded as a very useful compound.