Which drug classes are associated with anti-arrhythmics?

All of the mentioned drug classes—beta-blockers, calcium channel blockers, and potassium channel blockers—are commonly used as anti-arrhythmics, making the selection of all of the above correct.

Beta-blockers are effective in treating certain types of arrhythmias by decreasing the heart rate and reducing the workload on the heart. They do this primarily by blocking the effects of adrenaline on the heart's beta receptors, thereby mitigating rapid heart rates often seen in conditions like atrial fibrillation and ventricular tachycardia.

Calcium channel blockers also play a significant role in managing arrhythmias, particularly those arising from atrial origin. By inhibiting calcium influx through L-type calcium channels, these agents help in slowing conduction through the atrioventricular (AV) node, which can be beneficial in controlling heart rate and reducing the incidence of reentrant circuits.

Potassium channel blockers are crucial as they specifically prolong the action potential duration and refractory period of cardiac tissue. This action helps to normalize heart rhythms by reducing the excitability of myocardial cells and preventing re-entrant arrhythmias, making them essential for the treatment of conditions such as atrial fibrillation and certain types of ventricular tachycardia.

Thus, the inclusion of all three drug classes as