A system, the system comprising: one or more processors; and a memory coupled to the one or more processors, wherein the memory stores program instructions, wherein the program instructions are executable by the one or more processors to: obtain cardiac activity signals, at electrodes (114, 126) of an implantable medical device, in connection multiple cardiac beats and in connection with different IMD orientations relative to gravitational force; obtain acceleration signatures, at a sensor of the IMD, indicative of heart sounds generated during the cardiac beats; obtain device location information, at the IMD, with respect to the gravitational force during the cardiac beats; determine when the IMD shifts within a subcutaneous implant region based on the device location information; group the acceleration signatures associated with first and second sets of cardiac beats into a corresponding one of first and second posture bins based on the device location information and based on the determination of IMD shifts; and identify a difference between the acceleration signals in the first posture bin in connection with treating a heart condition. one or more processors; and a memory coupled to the one or more processors, wherein the memory stores program instructions, wherein the program instructions are executable by the one or more processors to: obtain cardiac activity signals, at electrodes (114, 126) of an implantable medical device, in connection multiple cardiac beats and in connection with different IMD orientations relative to gravitational force; obtain acceleration signatures, at a sensor of the IMD, indicative of heart sounds generated during the cardiac beats; obtain device location information, at the IMD, with respect to the gravitational force during the cardiac beats; determine when the IMD shifts within a subcutaneous implant region based on the device location information; group the acceleration signatures associated with first and second sets of cardiac beats into a corresponding one of first and second posture bins based on the device location information and based on the determination of IMD shifts; and identify a difference between the acceleration signals in the first posture bin in connection with treating a heart condition. obtain cardiac activity signals, at electrodes (114, 126) of an implantable medical device, in connection multiple cardiac beats and in connection with different IMD orientations relative to gravitational force; obtain acceleration signatures, at a sensor of the IMD, indicative of heart sounds generated during the cardiac beats; obtain device location information, at the IMD, with respect to the gravitational force during the cardiac beats; determine when the IMD shifts within a subcutaneous implant region based on the device location information; group the acceleration signatures associated with first and second sets of cardiac beats into a corresponding one of first and second posture bins based on the device location information and based on the determination of IMD shifts; and identify a difference between the acceleration signals in the first posture bin in connection with treating a heart condition.