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 (CA) signals, at electrodes of an implantable medical device (IMD) , 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 (CA) signals, at electrodes of an implantable medical device (IMD) , 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 (CA) signals, at electrodes of an implantable medical device (IMD) , 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. <EOS>