A medical device and medical device system for determining capture during delivery of a ventricular pacing therapy that includes a subcutaneous sensing device comprising a subcutaneous electrode to sense a subcutaneous cardiac signal and to emit a trigger signal in response to the sensed cardiac signal, an intracardiac therapy delivery device capable of being implanted within a left ventricle of a heart to receive the trigger signal and deliver the ventricular pacing therapy to the left ventricle in response to the emitted trigger signal, and a processor positioned within the subcutaneous sensing device, the processor configured to compare a beat of the subcutaneous cardiac signal sensed by the sensing device subsequent to the ventricular pacing therapy being delivered to a baseline template associated with a non-paced beat, and determine whether the delivered ventricular pacing therapy captures the left ventricle in response to the comparing.
