Plateau phase

The Plateau phase is a stage in the electrical activity of heart cells during a heartbeat, specifically in the process called action potential. During this phase, the heart cells maintain an electric charge because certain channels in the cell membrane open and stay open, allowing calcium ions to enter. This causes the cell to stay excited a little longer, which helps coordinate the heart's contraction. The Plateau ensures the heart muscle contracts fully and then relaxes properly before the next beat, maintaining a steady heartbeat and effective blood flow.