Which of the following is NOT a function of anti-arrhythmic drugs?

In the context of anti-arrhythmic drugs, their primary function is to help restore normal heart rhythms and to manage abnormal heartbeats. One of the key actions of these medications is to decrease conduction velocity, alter the excitability of cardiac cells, and suppress abnormal automaticity, which are all crucial in managing arrhythmias effectively.

Anti-arrhythmic drugs do not typically increase heart rate as this can exacerbate arrhythmias or lead to additional complications. Instead, their aim is often to stabilize the heart rhythm or slow down an excessively fast heart rate. By decreasing conduction velocity, they help slow down the electrical impulses in the heart, allowing for a more coordinated and effective heartbeat. Additionally, altering the excitability of cardiac cells contributes to preventing spontaneous arrhythmic activity. Suppressing abnormal automaticity also ensures that erratic electrical signals, which can lead to arrhythmias, are minimized.

Thus, the notion that anti-arrhythmic drugs can increase heart rate is misaligned with their intended therapeutic effects.