What detects the heart's electrical activity on the patient's skin?

The detection of the heart's electrical activity on the patient's skin is achieved through the use of electrodes. Electrodes are conductive pads that are placed on the skin to capture the electrical signals generated by the heart. These signals are then transmitted to a monitoring device or an electrocardiograph for recording and analysis.

Each electrode acts as a sensor that detects and measures the electrical impulses associated with heartbeats. This information is vital for diagnosing various cardiac conditions, as it reflects the heart's rhythm and electrical activity in real-time.

While leads refer to the connections that transmit signals from the electrodes to the monitoring equipment, they themselves do not directly detect electrical activity. Transmitters and monitors refer to devices that process and display the data gathered by electrodes, but it is the electrodes themselves that perform the initial detection of the heart’s electrical activity.