Let's look at what happens in the heart's electrical pathways during an abnormally slow heartbeat. An abnormally slow heartbeat is a heart rhythm problem called a bradyarrhythmia. Sometimes, this can be caused by the heart's electrical signals not working properly.
Usually this happens at the SA node or where the electrical signals cross from the atria into the ventricles. In a bradyarrhythmia that starts from the SA node, the signals may be sent too slowly, which is called bradycardia.
In other cases, they may alternate between being too fast and too slow. This is called sick sinus. Sometimes the signals may just stop, which is called sinus arrest. In other bradyarrhythmias, signals may not be able to travel all the way through the heart's electrical pathway to the ventricle. This is called heart block.
The end result is that the heart contracts too slowly and may not pump enough blood to the body and brain. This condition can cause minor problems or very serious life-threatening situations.
