According to at least one aspect, a wearable cardiac device is provided. The wearable cardiac device includes a garment worn about a torso of a patient, at least one sensing electrode to monitor cardiac activity of the patient, and a controller including a plurality of separate and distinct modules distributed about and/or integrated into the garment. The plurality of separate and distinct modules includes, for example, an operations module coupled to the at least one sensing electrode and configured to detect at least one cardiac condition of the patient and/or a communications module coupled to the operations module to communicate with an external device. In some examples, the wearable cardiac device may be configured as a treatment device and include an energy storage module coupled to at least one therapy electrode and configured to store energy for at least one therapeutic shock to be applied to the patient.