NEW POSSIBILITIES OF PHARMACOLOGICAL CARDIOVERSION OF NEWLY DEVELOPED PAROXYSM OF ATRIAL FIBRILLATION
Atrial fibrillation (AF) is one of the most common cardiac arrhythmias. The review presents the current possibilities of pharmacological cardioversion of AF paroxysm, the mechanisms of action which are applied in practical cardiology antiarrhythmics (AAS) of the various classes are presented. One of these new AAS is vernakalant (drug formulation - solution for intravenous administration), the mechanism of antiarrhythmic action which is associated with selective inhibition of atrial mostly voltage-dependent potassium channels, especially potassium channels delayed rectifier current (IKur) and channels activated by acetylcholine (KAch). Furthermore, vernakalant inhibits frequency-dependent and voltage-dependent sodium channels as well localized in the atria. The data on the pharmacokinetics of vernakalant and the results of its clinical application. Evaluating the results of numerous clinical studies, we can conclude that the new AAS vernakalant is effective and safe in relieving the AF, which lasts from 3 hours to 7 days. The initial dose is 3 mg/kg is administered intravenously over 10 min, with no effect after 15 minutes possible re-introduction in dose of 2 mg/kg. However, the probability of restoring sinus rhythm in the absence of the effect of the first dose is significantly reduced. With a longer period the AF or TA effectiveness of the drug is extremely low. Good clinical effect of vernakalant, and provides for AF, occurred after cardiac surgery. Ability of vernakalant to cause ventricular arrhythmias (ventricular fibrillation, ventricular tachycardia type "feast") appears minimal. In general, the researchers indicate good tolerability of vernakalant.