Calcium as a free floating ion shouldn't exist in the cell because it's actually harmful, and that will probably lead to the cell's death. It has to be held in high abundance but not too much - so either smooth or plesent riticulum is needed. There's a drug called dejoxen which stops the sodium potassium 80 p a pump,. This means you can't exchange sodium with calcium. And calcium builds up inside the heart muscle, which means the heart muscle has a greater and gr o abundance of calcium than before.