The cardiac muscle (or heart muscle) makes up the bulk of the heart’s mass. This muscle is an extremely specialized form of muscle that pumps blood throughout the body. In normal adults, the heart will beat at a rate of 60 to 100 times per minute. Arrhythmia is a set of conditions in which the heartbeat is irregular – either too slow or too fast. According to the Mayo Clinic, there are more than 3 million cases of arrhythmias in the USA per year. The symptoms of a cardiac arrhythmia may include palpitations, dizziness, fainting spells, fatigue, shortness of breath, and chest pain.
The heart’s upper two chambers are the atria, and the two lower chambers are the ventricles. Normally, the signal for the heart to beat comes from the heart’s sinus node (seen in the upper portion of the right atrium) which works as a natural pacemaker. The heartbeat signal then travels to the atrioventricular node (found between the atria) and onto the muscles of the ventricles. This stimulates the ventricles to contract, resulting in a heartbeat(1).
The importance of a properly performing heart to one’s health is unquestioned, and there is much scientific evidence that good nutrition plays a significant role in support of heart health and a normal heartbeat. Studies have demonstrated that some of the most crucial minerals for heart health include magnesium, potassium, and calcium. These minerals play very specific roles in the generation of a proper heartbeat. Calcium and magnesium work together to control muscle contraction, while sodium and potassium help the nerve cells send electrical signals that signal the muscles to contract. Today we take a closer look at calcium’s specific roles in heart health.
Calcium’s Role in Heart Health
Calcium is known for its essential involvement in the building and maintenance of bones. However, it also plays a critical role in the function of the heart. The heart is formed from specialized muscle cells that when functioning properly work automatically, without the heart skipping a beat. The stimulation for the contraction of the cardiac muscle is a bit different from the stimulation of skeletal muscle contraction. We can willingly stimulate skeletal muscle contraction, which is not so for the cardiac muscles. The muscles work automatically, at a rate of about 70 beats or contractions per minute. Meaning that the heart muscles must contract and relax about 100,000 times per day(2).
Calcium is critical to the regulation of the contraction and relaxation of the cardiac muscle. Cardiac muscles contract from the stimulation of a unique group of cardiac cells known as the sinoatrial node (SA node). Cardiac muscle contraction is directly determined by the level of calcium elevation during the phase of the heartbeat when the heart muscle contracts and pumps blood from the chambers into the arteries(3). Calcium fires the SA node, which stimulates the rest of the cardiac cells to contract, and the heartbeat is made. A defect in the removal of calcium from the cytosol during diastole would impair cardiac relaxation, which is needed to allow the heart chambers to refill with the blood needed for the next contraction.
Proper heart rhythm is reliant on the adequate dietary intake of calcium. Balchem’s Albion minerals provide a gentle and bioavailable form of calcium called Calcium Bisglycinate Chelate. Supplementing the diet with this form of calcium helps to ensure that an adequate amount of calcium is absorbed and utilized by the body. Look for supplements containing this form.
The cardiac muscle or heart muscle makes up the bulk of the heart’s mass. It is one of the body’s three muscle groups: skeletal, smooth, and cardiac muscle. Cardiac muscle is an extremely specialized form of muscle that pumps blood throughout the body. Cardiac muscle is only found in the heart.
Proper heart rhythm is reliant on the adequate dietary intake of four minerals: calcium, magnesium, potassium, and sodium. Calcium and magnesium work together to control muscle contraction. While magnesium plays a significant role in heart health, a large part of the population is deficient in magnesium and would benefit from supplementation to support heart health.
Magnesium’s Role in Heart Health
The heart has the highest magnesium requirement of any organ in the human body, especially the left ventricle. Magnesium is important for coordinating the activity of the cardiac muscles (myocytes). It has been shown that low magnesium increases one’s risk for cardiac arrhythmias and heart palpitations. Magnesium deficiency can reduce pump activity, resulting in partial depolarization and changes in the activity of many potential-dependent membrane channels(3). Magnesium has been reported to increase the sinus node recovery time, atrioventricular node (AVN) conduction time during sinus rhythm, atrial-paced cycle length, AV node refractory period, and effective refractory period(4). This allows the heart to relax longer and allows for more effective refilling. Low magnesium levels have been seen to result in a variety of cardiac arrhythmias, such as atrial fibrillation and atrial flutter. Magnesium’s electrophysiological actions have been shown to help prevent premature ventricular contractions.
Balchem’s Albion minerals provide a highly bioavailable form of magnesium called Magnesium Bisglycinate Chelate. Supplementing the diet with Albion minerals can help to ensure that an adequate amount of magnesium is being absorbed and utilized by the body. Look for supplements containing this form of magnesium.
Proper heart rhythm is reliant on the adequate dietary intake of minerals, particularly calcium, magnesium, potassium, and sodium. Sodium and potassium work together to help signal the cardiac muscles to contract and relax normally.
Potassium’s Critical Role in Supporting Heart Health
Electrolytes, including sodium and potassium, both play critical roles in the maintenance of proper heart rhythm. The rhythmic contractions of the heart are controlled by periodic changes in the membrane potential of the cardiac myocytes. The SA node initiates the start of the heart beat (it maintains its own automaticity). Once the SA node fires, the myocytes cause their rhythmic contraction/relaxation waves. The rhythmic contraction of the heart is controlled by periodic changes of the membrane potential of the cardiac myocytes, called action potentials(5). The cardiac action potentials consist of 5 phases. First there is the time of rapid depolarization, in which sodium flows into the cell. This is followed by a short and small repolarization, which is followed by a long plateau at a depolarized level. Then, repolarization of the plateau potential takes place, and the final phase continues to the next rapid depolarization. The action potential is the result of a concerted action of inward (depolarizing) and outward (hyperpolarizing) ionic currents. The outward component is carried by potassium (K+) ions through potassium-permeable transmembrane proteins, the potassium channels.
So, the control of contraction and relaxation of the cardiac muscles requires a proper quantitative relation between extracellular sodium and intracellular potassium. If these are out of balance, the heart rhythm is disrupted – leading to different types of arrhythmias.
Interested in learning more?
Balchem’s Albion minerals can provide one with bioavailable forms of calcium, magnesium, and potassium. These minerals can be used as a dietary supplement to ensure adequate intake in the diet.
- Harvard Medical School. (2018). Cardiac Arrhythmias Retrieved June 27, 2018, from Harvard Health Online
- Stephanie C. (2017). Cardiac Cell Functions Retrieved Aug. 14, 2017, from Livestrong.com:
Marks AR. (2003). Journal of Clinical Investigation, 111(5):597-600.
- ANGUS M., ANGUS Z. (2001). Cardiovascular actions of magnesium. Crit Care Clin, 53:299-307
- Cieslewicz A., et al. (2013). Journal of Elementology. 181, 317-327
- Markwardt F. (2002). The Role of Potassium Ions in the Control of Heart Function. In: Foà P.P., Walsh M.F. (eds) Ion Channels and Ion Pumps. Endocrinology and Metabolism (Progress in Research and Clinical Practice), vol 6. Springer, New York, NY