It depdends: There are many causes of toe spasms/cramps and it is important to identify the source. Cramps and spasms can be due to dehydration and low potassium. But they can also be due to a nerve conditions as well. I recommend you see a specialist for further evaluation. ...Read more.
1 The SA node (called the pacemaker of the heart) sends out an electrical impulse. 2  The upper heart chambers (atria) contract. 3  The AV node sends an impulse into the ventricles.  The lower heart chambers (ventricles) contract or pump.
This article is about the natural pacemaker in the heart. For the medical device that simulates the function, see artificial cardiac pacemaker. Image showing the cardiac pacemaker or SA node, the normal pacemaker within the electrical conduction system of the heart. The contraction of cardiac muscle (heart muscle) in all animals is initiated by electrical impulses known as action potentials. The rate at which these impulses fire controls the rate of cardiac contraction, that is, the heart rate. The cells that create these rhythmic impulses, setting the pace for blood pumping, are called pacemaker cells, and they directly control the heart rate.