Event monitors are similar to Holter monitors that are worn during normal daily activities. Most event monitors have wires that connect the device to sensors. The sensors are stuck to your chest using sticky patches.They only record heart rhythm during symptoms and there is usually a button that needs to pressed to start recording. Some event monitors start automatically if they detect abnormal heart rhythms. These are small and are connected via cell phone technology. These can be worn from a few days to a few weeks.