Abstract:
Introduction: Antiarrhythmic drugs are preparations used in the treatment of cardiac
arrhythmias. Arrhythmias are found in 95% of cases of myocardial infarction within 48 hours, and
many people, including young people die from ventricular fibrillation, but not from myocardial
infarction, which is usually very small.
According to Vaughan-Williams antiarrhythmics are divided into 4 classes:
1. Class I agents interfere with the sodium (Na+) channel.
2. Class II agents are anti-sympathetic nervous system agents. Most agents in this class are
beta blockers.
3. Class III agents affect potassium (K+) efflux.
4. Class IV agents affect calcium channels and the AV node.
The purpose of the work: To make a schema that will be described mechanism of action and
effects of drugs onion channels
Methods: Literature study about antiarrhythmic drugs and their action on ion channels
Results: The class I antiarrhythmic agents interfere with the sodium channel. Class I agents
are grouped by what effect they have on the Na+ channel, and what effect they have on cardiac
action potentials. Class I agents are divided into three groups (la, lb and Ic) based upon their effect
on the length of the action potential. Class III agents predominantly block the potassium channels,
thereby prolonging repolarization. Inhibiting potassium channels, slowing repolarization, results in
slowed atrial-ventricular myocyte repolarization. Class IV agents are slow calcium channel
blockers. They decrease conduction through the AV node, and shorten phase two (the plateau) of
the cardiac action potential. Class II was not described, because they have notation onion channels.
Conclusion: Knowing classes of antiarrhythmic drugs, and their action onion channels, we
will be able to choose appropriate preparation with antiarrhythmic action, according to the patient's
pathology.
Description:
Department of Pharmacology and Clinical Pharmacology, State University of Medicine and Pharmacy “Nicolae
Testemitanu”, Chişinău, Republic of Moldova
