Calcium channel blockers have what dromotropic effect?

Calcium channel blockers have what dromotropic effect?

• A. Positive
• B. Negative
• C. Neutral
• D. None

Answer: (B)

Calcium channel blockers slow conduction through the AV node by blocking the L-type calcium channels that drive nodal conduction. This reduces how quickly impulses pass from atria to ventricles, giving a negative dromotropic effect. Verapamil and diltiazem are classic examples that produce this effect, which is why they’re used for rate control in atrial tachyarrhythmias. In contrast, many dihydropyridine blockers mainly affect vascular smooth muscle and have little impact on AV nodal conduction, so their dromotropic effect is minimal.

Calcium channel blockers slow conduction through the AV node by blocking the L-type calcium channels that drive nodal conduction. This reduces how quickly impulses pass from atria to ventricles, giving a negative dromotropic effect. Verapamil and diltiazem are classic examples that produce this effect, which is why they’re used for rate control in atrial tachyarrhythmias. In contrast, many dihydropyridine blockers mainly affect vascular smooth muscle and have little impact on AV nodal conduction, so their dromotropic effect is minimal.