Devices, systems, and methods for sensing cardiac electrical activity and blood pressure within a blood vessel are disclosed. A vascular sensor includes a fixation element configured to secure the vascular sensor within a blood vessel, a sensor module housing coupled to the fixation element, a pressure sensor disposed within an interior portion of the housing and configured to sense blood pressure within the vessel, and a number of electrocardiogram sensing electrodes exposed to tissue and blood within the blood vessel and configured to sense cardiac electrical data within the blood vessel. A controller module processes the sensed cardiac electrical data and blood pressure data and stores the data within a memory unit and/or transmits the data to a communicating device in wireless communication with the vascular sensor.