[Calcium metabolism and transmembrane potential of thrombocytes in patients with frequent ventricular extrasystole treated with anti-arrhythmia drugs].

The effect of antiarrhythmic drugs on platelet calcium metabolism in peripheral blood has been examined. Anti-arrhythmic agents (ethmozine, ethacizine, quinidine, disopyramide, amiodarone), used extensively for the control of various heart rhythm disorders, as well as calcium antagonists (verapamil were shown to have a calcium-blocking property. It is demonstrated that the rate of reduction in the total number of extrasystoles in the presence of antiarrhythmic drugs is correlated to the magnitude of their in vitro calcium-blocking effect. It can be assumed that the action of antiarrhythmic drugs is in part mediated by their effect on calcium currents; at the same time, disorders of Ca2+ transport in myocardial cells are a cause of developing arrhythmias. The ability of antiarrhythmic drugs to affect platelet calcium ion currents may be used for preliminary assessment of the efficiency of antiarrhythmic drugs, used clinically to control heart rhythm disorders.