[Hemodynamic effects of anti-arrhythmia substances]

Medical treatment of cardiac arrhythmias is limited by several side effects. Haemodynamic and proarrhythmic effects are the most important limitations of antiarrhythmic drug therapy. In this paper we present data from several studies on the haemodynamic side effects of antiarrhythmic drugs of Class I and III according to Vaughan-Williams. The results were discussed with special regard to the influence of these drugs on myocardial contractility. From the results presented it is concluded that there are no important differences in the negative inotropic effects among the Class I drugs. The clinically observed more marked cardiodepressant action of some of these drugs is probably due to their unfavourable effects on pre- and afterload of the left ventricle. From a theoretical point of view, Class III drugs should have a more favourable haemodynamic profile. However, after acute administration the commercially available Class III drugs also had a cardiodepressant action. A possible explanation for this finding might be other side effects of the Class III drugs currently available, since a pure Class III drug does not exist at present. Therefore, the special haemodynamic profile of each drug should be taken into consideration for antiarrhythmic treatment.