Sometimes a person with heart disease will experience tightness in the chest, which is called angina. This isn't a heart attack, but it's definitely a major warning that one could be on its way. Angina occurs when the heart isn't receiving enough oxygen to function properly. One way of relieving angina is through the use of calcium channel blockers (CCBs).
CCBs relax the blood vessels and help expand the arteries, allowing more oxygenated blood to pass to and from the heart. By doing so, CCBs lower blood pressure. They also prevent calcium from penetrating blood vessel walls. This is important because calcium hardens the blood vessels, diminishing their function and creating more work for the heart.
Some CCBs work quickly, but the effects don't last long, while others work slowly over time, with longer-lasting effects.