Devices are described herein including mounts configured to removably mount electrodes and other elements of the devices to a garment (e.g., a close-fitting undergarment) of a wearer. The devices include at least two electrodes configured such that the electrodes are maintained in secure electrical contact with skin of the wearer when the device is so mounted. The devices can be mounted to garments at various locations on the torso of the wearer such that an electrocardiographic signal related to the electrical activity of the heart of the wearer can be extracted from voltage fluctuations between the at least two electrodes. Such devices can be used for continuous logging or other applications of the electrocardiographic signals of the wearer. Such logged electrocardiographic signals could be used to determine a medical or health state of the wearer.