Question

What effects does the drug "diltiazem" have on calcium and action potential duration in the heart?

A) Increases calcium influx; Prolongs action potential duration
B) Decreases calcium influx; Shortens action potential duration
C) Increases calcium efflux; Shortens action potential duration
D) Decreases calcium efflux; Prolongs action potential duration

Answer 1

Diltiazem, a calcium channel blocker, decreases calcium influx and shortens action potential duration in the heart.

Step-by-step explanation:

The drug diltiazem affects calcium influx and action potential duration in the heart. It is a calcium channel blocker, which means it blocks or slows the inward movement of calcium ions through calcium channels. This ultimately leads to a decrease in calcium influx, resulting in a decrease in action potential duration. Therefore, the correct option is B) Decreases calcium influx; Shortens action potential duration.