Systems and methods for evaluating electrostimulation of a heart are disclosed. A system can comprise an electrostimulation circuit that can deliver multi-site electrostimulation, including pacing at two or more sites of the heart during the same cardiac cycle. The system can comprise a heart sound sensor circuit configured to sense a heart sound (HS) signal during multi-site stimulation. The heart sound sensor circuit can also sense HS signals in response to uni-site stimulation at a specified site capturing at least a portion of the heart. The system can comprise a pacing analyzer circuit that uses the HS signals during the multi-site stimulation and during the uni-site stimulation to determine a capture status indication that indicates whether the multi-site stimulation captures the two or more sites of the heart, and can be one of a full capture indication, a partial capture indication, or a loss of capture indication.
