Various types of cardiac cells come together to form the cardiac muscles. These are also known as ‘heart cells’ in some cases. These help the heart in its function of providing different parts of the body with blood. Since the heart is the strongest muscle in the body and beats 24 hours of the day, 7 days a week until we die, these types of cardiac cells are quite complex and different from other cells in our body. For starters they only have one nucleus. These cells coordinate and work at the same time to ensure that blood is transported throughout the body.
Only if the various types of cardiac cells work at the same time can blood be transported throughout the entire body. These types of cardiac cells are known as cardiomyocytes. They are quite strong and weakening of these types of cardiac cells would result in poor transport of blood around the body. The cardiac muscle is quite strong because of these types of cardiac cells and persists till death. Certain medications would make it possible for blood to flow to those parts of the heart that are damaged. This could either happen due to trauma, an injury or because it is in your genes.
The other of the two types of cardiac cells is known as the cardiac pacemaker. These create rhythmic pulses to ensure that the heart rate is kept at a constant pace. You know how they say that the heart beats 70 times per minute? That is controlled by these types of cardiac cells. These types of cardiac cells are very important because they ensure that the blood flows through our bodies at a constant pace- at a pace that is required by our bodies to survive.
A heart attack usually occurs when blood vessels servicing the heart are not supplied with the blood they require and so no blood is transported to those types of cardiac cells that are around the arteries. As a result the cells cannot transport blood to important parts of the heart and the heart then stops functioning gradually. The heart and the cells go into ‘shut down’ mode and that is how a heart attack would cause death. It is no longer possible to revive them once they go into this ‘phase’ though according to recent discoveries it may be possible to revive them by using stem cells. New blood can be supplied to them so that they do not die completely. This would help keep a person alive for longer despite the fact that these types of cardiac cells are not receiving blood.
In some cases it may be possible to revive a person by using a defibrillator which is used to stop the heart from racing away and to bring it back into sync but this has nothing to do with cardiac cells.
It was initially thought that these cells cannot regenerate or be renewed. In 2009 it was that both types of cardiac cells can indeed be renewed and regenerated despite of what most people though was the case at first.