Drugs affecting the cardiac action potential. The sharp rise in voltage ("0") corresponds to the influx of sodium ions, whereas the two decays ("1" and "3", respectively) correspond to the sodium-channel inactivation and the repolarizing efflux of potassium ions. The characteristic plateau ("2") results from the opening of voltage-sensitive calcium channels.|alt=Plot of membrane potential versus time. The initial resting phase (region 4) is negative and constant flowed by sharp rise (0) to a peak (1). The plateau phase (2) is slightly below the peak. The plateau phase is followed by a fairly rapid return (3) back to the resting potential (4).<unk> s, also known as cardiac dysrhythmia medications, are a group of pharmaceuticals that are used to suppress abnormal rhythms of the heart (cardiac arrhythmias), such as atrial fibrillation, atrial flutter, ventricular tachycardia, and ventricular fibrillation. Many attempts have been made to classify<unk> s. The problem arises from the fact that many of the<unk> s have multiple modes of action, making any classification imprecise.
Antiarrhythmic agent
Antihypotensive agent
Lipid-lowering agent
Neuromuscular blocking agents
Antihypertensive drug
Antiplatelet drug
Neuromuscular-blocking drug
Antidote