Cardiovascular diseases have been leading the list of causes of death for several decades. However, in recent years, in most developed countries, namely Japan, Germany, France, England, Canada, and the United States, people began to die less often of cardiovascular disease and, accordingly, live longer.
Average life expectancy is not a very informative indicator, as it largely depends on child mortality. Life expectancy is much more interesting for those who succeeded in childhood. So, in Japan, people live on average up to 78 years. This achievement is, of course, the result of a whole complex of therapeutic, surgical, and even psychological efforts. But a decisive role in this victory was played by the development of a group of drugs called calcium channel blockers. Let’s consider this type of heart medication in more detail.
How does calcium affect the health of the heart?
The physicians have recently realized that calcium plays an especially important role in muscle contraction. Calcium has remained “invisible” for a long time: even with a very large content of this substance in human blood inside the cells it is small and it is firmly connected with proteins. The concentration of free ionized calcium in the cytoplasm of muscles is negligibly low. However, within a tenth of a second, for which the electrical potential covers the muscle fiber, the concentration of free calcium in it increases by a factor of 100,000! Researchers have found that it comes into contact with the contractile elements of the muscle and causes them to be shortened, while at the same time “triggering” the mechanism of oxygen absorption, storage and consumption of energy needed to work.
Where does free calcium come from in the muscle? It penetrates through special “fast” ion channels and is also released from the depots where it is stored. When the excitation is over, the excess calcium ions reconnect with the proteins or are pushed out through the same “fast” channels. The cell is then ready for excitation again.
The heart muscle is special. It is very different from the muscles that move the arms and legs. Its special feature is that it works like a pump. It has almost no “fast” calcium channels. When excited, the bulk of free calcium ions pass through the “slow” channels. This leads to the release of internal calcium ions from the depot, and the reduction develops slowly. Part of the muscle fibers of the heart has lost its contractile functions and turned into a kind of system that conducts nerve impulses – a kind of nervous system. This conductive system begins at the base of the atria, where the so-called sinus node is located, which is capable of independently producing electrical signals. Its second name is the driver of rhythm. Having originated in the sinus node, the nerve impulse spreads throughout the heart.
Calcium also enters the cells of the conductive system mainly through “slow” channels. From the cells of the rhythm driver, the impulse spreads through the atria at a rate of about one meter per second, then is necessarily trapped in the atrio-ventricular node of the heart, which provides a sequence of contractions of atria and ventricles, and then with some acceleration covers the ventricles. In the skeletal muscle of the same diameter, the impulse passing speed is almost 10 times higher, and along the nerve fiber the impulse passes even faster.
So, you should not forget about modern developments and look for exactly those drugs that can be most effective. For example, there are many excellent diabetes medications that you can take if you have a problem.