Calcium and Cardiac Function

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Calcium is elemental in building bones, but this mineral also has a connection to the heart beat. The cardiac muscle keeps the heart pumping at an average rate of 70 beats per minute. The heart must contract and relax more than 100,000 times a day. The mineral calcium is critical in triggering timely and strong enough contractions in the cardiac muscle to circulate blood throughout the body.

Calcium and Cardiac Muscle

The heart is formed from specialized muscle cells called cardiomyocytes that work automatically without skipping a single beat. Like other muscles, the cardiac muscles require calcium to contract and squeeze blood out of the heart and into the arteries. Calcium flows into the muscle cells through tiny channels and works as a switch that allows each heart muscle fiber to slide past each other and shorten to contract. At the end of each contraction, calcium flows out of the channels to allow the muscles to relax and lengthen again.

The Recommended Daily Dose

The American Heart Association recommends eating a balanced diet to get enough calcium. Eat rich sources of this mineral such as spinach, kale, broccoli and other vegetable greens, legumes, soybean products and low-fat dairy products. Men should get 1,000 to 1,200 milligrams per day while women need between 1,000 to 1,300 milligrams of calcium every day.

Excess Calcium Effects

A review published in the "Journal of Biomedical Science" notes that too much calcium can cause abnormalities in your heart muscles. This can lead to excessively forceful or tight contractions of your heart and cause an irregular heartbeat -- arrhythmia and fast heart rate. A calcium overload can also cause high blood pressure, chest pain -- angina -- and contribute to heart failure.

Medications That Affect Calcium

As their name suggests, calcium-channel blockers are prescription medications that work by limiting how much calcium gets into your heart muscles. They are used to treat a variety of heart conditions including angina and high blood pressure by reducing the force and rate of each heartbeat. Calcium-channel blockers cause the heart muscles to relax and reduce the pressure of blood flow in your arteries.