An apparatus, a system, and a method for monitoring and/or performing a diagnosis. A first implantable device measures a property of a first tissue in a body and includes a housing. The housing includes a first processing circuitry for causing the first implantable device to measure the property of the first tissue. A second implantable device for measures a property of a second tissue in the body and includes a housing. The housing includes a second processing circuitry for causing the second implantable device to measure the property of the second tissue using at least one sensor. The second implantable device is communicatively coupled to the first implantable device and provides information about the measured property of the second tissue to at least one of the following: the first implantable device and at least one processing device disposed externally to the body.