Which calcium channel blockers are known to lower a client's heart rate?

Verapamil is a calcium channel blocker that is specifically known for its ability to lower heart rate. This medication primarily affects the cardiovascular system by blocking calcium channels in the heart and blood vessels. As a result, it decreases the force of contraction of the heart muscle and the conduction of electrical impulses through the AV node, which leads to a reduction in heart rate.

In contrast, amlodipine and nifedipine are more selective for vascular smooth muscle and primarily function to reduce peripheral vascular resistance and blood pressure rather than significantly impacting heart rate. Diltiazem, while it does have some effects on heart rate, is often regarded as having a milder effect compared to verapamil. Therefore, verapamil is the most notable calcium channel blocker for managing conditions associated with an elevated heart rate, making it the correct choice in this context.