Electro static discharge (ESD) protection is provided for electronic devices with integrated circuits, such as for example heart rate monitors. The ESD protection protects against voltage accumulation and discharge through device external parts that are connected to internal device circuitry. The ESD protection isolates the internal device circuitry and provides a low impedance path over which electro static charges and any transient voltages in the device may discharge. The integrated circuits, electrical components, and other parts protected from ESD may be connected to monitor circuitry and be externally exposed, such as sensing or measurement parts exposed outside the device. The external parts may include a sensing case back, sensing push-buttons, or other components that provide a signal to or are otherwise in communication with the internal device circuitry.