Which medication is considered an example of an anti-arrhythmia agent?

Lidocaine is an anti-arrhythmia agent commonly used in medical practice to manage certain types of cardiac arrhythmias. It works as a Class 1B antiarrhythmic drug, primarily affecting sodium channels in the heart. By stabilizing the cardiac cell membrane and decreasing excitability, Lidocaine helps to restore a normal rhythm in the heart, making it effective in treating ventricular arrhythmias, particularly those that may arise after a myocardial infarction.

The other medications listed do not serve the primary function of managing arrhythmias. Aspirin is an antiplatelet agent used mainly for preventing blood clots. Meperidine is an opioid analgesic used for pain management, and Heparin is an anticoagulant that prevents the formation of blood clots in various medical situations. Each of these agents has its unique mechanisms of action and therapeutic uses that do not pertain to the modulation of heart rhythms.