Calcium channel blockers are medicines commonly used to:

• Lower blood pressure and prevent chest pain in people who have angina.
• Treat hypertension.

The following calcium channel blockers can also slow heart rate:

• Diltiazem (such as Cardizem)
• Verapamil (such as Calan)

Diltiazem and verapamil are used for atrial fibrillation.

By slowing heart rate and lowering blood pressure, calcium channel blockers help reduce the heart's workload. Calcium channel blockers may also directly improve blood flow to the heart by reversing spasms that can occur in the coronary arteries, which supply blood to the heart muscle. Successful treatment of high blood pressure also helps reduce the risk of atrial fibrillation.