An implantable medical device (IMD) includes an optical hemodynamic sensor comprising at least one optical emitter and at least one detector. In some examples, the at least one optical emitter may be optically coupled to at least one light transmission member that extends from a housing of the IMD. In addition, in some examples, the at least one detector may be optically coupled to at least one light transmission member that extends from the housing of the IMD. In other examples, an optical emitter and/or detector of a hemodynamic sensor may be carried by an extension member that extends from a housing of the IMD. The elongated member may electrically couple the optical emitter and/or detector to a controller or other components within the IMD housing.