Does the heart rate stabilize and remain stable with calcium ions?

Yes, the heart rate stabilizes and remains stable with calcium ions.

Calcium ions play a crucial role in regulating the heart's electrical activity, which controls the heart rate. The influx of calcium ions into cardiac muscle cells during the cardiac action potential triggers the release of more calcium ions from intracellular stores, leading to muscle contraction. This process, known as calcium-induced calcium release, is essential for the normal, rhythmic contraction of the heart.

When calcium ion levels are within the optimal range, the heart rate is stable and regular. However, if calcium ion levels are too low or too high, it can disrupt the electrical signals that coordinate the heart's contractions, leading to abnormal heart rhythms (arrhythmias).

For instance, low calcium ion levels (hypocalcemia) can prolong the cardiac action potential and slow down the heart rate, while high calcium ion levels (hypercalcemia) can shorten the action potential and increase the heart rate.

Therefore, maintaining the proper balance of calcium ion concentrations is crucial for stabilizing and sustaining a regular heart rate.